[Qemu-devel] [PATCH v5 0/4] colo: Add support for continuous replication

[Qemu-devel] [PATCH v5 0/4] colo: Add support for continuous replication

[Lukas Straub]

Hello Everyone,
These Patches add support for continuous replication to colo. This means
that after the Primary fails and the Secondary did a failover, the Secondary
can then become Primary and resume replication to a new Secondary.

On a side note, I wrote a Pacemaker Resource Agent for colo which I will
post when its ready.
I have to say it's quite fun to randomly kill a Node, wait for resync
and repeat and see how the VM stays alive all the time. :)

Regards,
Lukas Straub

v5:
 - change syntax for the position= parameter
 - fix spelling mistake

v4:
 - fix checkpatch.pl warnings

v3:
 - add test for replication changes
 - check if the filter to be inserted before/behind belongs to the same interface
 - fix the error message for the position= parameter
 - rename term "after" -> "behind" and variable "insert_before" -> "insert_before_flag"
 - document the quorum node on the secondary side
 - simplify quorum parameters in documentation
 - remove trailing spaces in documentation
 - clarify the testing procedure in documentation

v2:
 - fix email formating
 - fix checkpatch.pl warnings
 - fix patchew error
 - clearer commit messages


Lukas Straub (4):
  block/replication.c: Ignore requests after failover
  tests/test-replication.c: Add test for ignoring requests after
    failover
  net/filter.c: Add Options to insert filters anywhere in the filter
    list
  colo: Update Documentation for continuous replication

 block/replication.c        |  38 ++++++-
 docs/COLO-FT.txt           | 212 +++++++++++++++++++++++++++----------
 docs/block-replication.txt |  28 +++--
 include/net/filter.h       |   2 +
 net/filter.c               |  92 +++++++++++++++-
 qemu-options.hx            |  10 +-
 tests/test-replication.c   |  52 +++++++++
 7 files changed, 358 insertions(+), 76 deletions(-)

--
2.20.1

[Qemu-devel] [PATCH v5 1/4] block/replication.c: Ignore requests after failover

[Lukas Straub]

After failover the Secondary side of replication shouldn't change state, because
it now functions as our primary disk.

In replication_start, replication_do_checkpoint, replication_stop, ignore
the request if current state is BLOCK_REPLICATION_DONE (sucessful failover) or
BLOCK_REPLICATION_FAILOVER (failover in progres i.e. currently merging active
and hidden images into the base image).

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
---
 block/replication.c | 38 +++++++++++++++++++++++++++++++++++---
 1 file changed, 35 insertions(+), 3 deletions(-)

diff --git a/block/replication.c b/block/replication.c
index 3d4dedddfc..97cc65c0cf 100644
--- a/block/replication.c
+++ b/block/replication.c
@@ -454,6 +454,17 @@ static void replication_start(ReplicationState *rs, ReplicationMode mode,
     aio_context_acquire(aio_context);
     s = bs->opaque;

+    if (s->stage == BLOCK_REPLICATION_DONE ||
+        s->stage == BLOCK_REPLICATION_FAILOVER) {
+        /*
+         * This case happens when a secondary is promoted to primary.
+         * Ignore the request because the secondary side of replication
+         * doesn't have to do anything anymore.
+         */
+        aio_context_release(aio_context);
+        return;
+    }
+
     if (s->stage != BLOCK_REPLICATION_NONE) {
         error_setg(errp, "Block replication is running or done");
         aio_context_release(aio_context);
@@ -529,8 +540,7 @@ static void replication_start(ReplicationState *rs, ReplicationMode mode,
                    "Block device is in use by internal backup job");

         top_bs = bdrv_lookup_bs(s->top_id, s->top_id, NULL);
-        if (!top_bs || !bdrv_is_root_node(top_bs) ||
-            !check_top_bs(top_bs, bs)) {
+        if (!top_bs || !check_top_bs(top_bs, bs)) {
             error_setg(errp, "No top_bs or it is invalid");
             reopen_backing_file(bs, false, NULL);
             aio_context_release(aio_context);
@@ -577,6 +587,17 @@ static void replication_do_checkpoint(ReplicationState *rs, Error **errp)
     aio_context_acquire(aio_context);
     s = bs->opaque;

+    if (s->stage == BLOCK_REPLICATION_DONE ||
+        s->stage == BLOCK_REPLICATION_FAILOVER) {
+        /*
+         * This case happens when a secondary was promoted to primary.
+         * Ignore the request because the secondary side of replication
+         * doesn't have to do anything anymore.
+         */
+        aio_context_release(aio_context);
+        return;
+    }
+
     if (s->mode == REPLICATION_MODE_SECONDARY) {
         secondary_do_checkpoint(s, errp);
     }
@@ -593,7 +614,7 @@ static void replication_get_error(ReplicationState *rs, Error **errp)
     aio_context_acquire(aio_context);
     s = bs->opaque;

-    if (s->stage != BLOCK_REPLICATION_RUNNING) {
+    if (s->stage == BLOCK_REPLICATION_NONE) {
         error_setg(errp, "Block replication is not running");
         aio_context_release(aio_context);
         return;
@@ -635,6 +656,17 @@ static void replication_stop(ReplicationState *rs, bool failover, Error **errp)
     aio_context_acquire(aio_context);
     s = bs->opaque;

+    if (s->stage == BLOCK_REPLICATION_DONE ||
+        s->stage == BLOCK_REPLICATION_FAILOVER) {
+        /*
+         * This case happens when a secondary was promoted to primary.
+         * Ignore the request because the secondary side of replication
+         * doesn't have to do anything anymore.
+         */
+        aio_context_release(aio_context);
+        return;
+    }
+
     if (s->stage != BLOCK_REPLICATION_RUNNING) {
         error_setg(errp, "Block replication is not running");
         aio_context_release(aio_context);
--
2.20.1

[Qemu-devel] [PATCH v5 2/4] tests/test-replication.c: Add test for ignoring requests after failover

[Lukas Straub]

This simulates the case that happens when we resume COLO after failover.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
---
 tests/test-replication.c | 52 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)

diff --git a/tests/test-replication.c b/tests/test-replication.c
index f085d1993a..5addfc2227 100644
--- a/tests/test-replication.c
+++ b/tests/test-replication.c
@@ -489,6 +489,56 @@ static void test_secondary_stop(void)
     teardown_secondary();
 }

+static void test_secondary_failover_then_ignore_requests(void)
+{
+    BlockBackend *top_blk, *local_blk;
+    Error *local_err = NULL;
+
+    top_blk = start_secondary();
+    replication_start_all(REPLICATION_MODE_SECONDARY, &local_err);
+    g_assert(!local_err);
+
+    /* write 0x22 to s_local_disk (IMG_SIZE / 2, IMG_SIZE) */
+    local_blk = blk_by_name(S_LOCAL_DISK_ID);
+    test_blk_write(local_blk, 0x22, IMG_SIZE / 2, IMG_SIZE / 2, false);
+
+    /* replication will backup s_local_disk to s_hidden_disk */
+    test_blk_read(top_blk, 0x11, IMG_SIZE / 2,
+                  IMG_SIZE / 2, 0, IMG_SIZE, false);
+
+    /* write 0x33 to s_active_disk (0, IMG_SIZE / 2) */
+    test_blk_write(top_blk, 0x33, 0, IMG_SIZE / 2, false);
+
+    /* do failover (active commit) */
+    replication_stop_all(true, &local_err);
+    g_assert(!local_err);
+
+    /* it should ignore all requests from now on */
+
+    /* start after failover */
+    replication_start_all(REPLICATION_MODE_PRIMARY, &local_err);
+    g_assert(!local_err);
+
+    /* checkpoint */
+    replication_do_checkpoint_all(&local_err);
+    g_assert(!local_err);
+
+    /* stop */
+    replication_stop_all(true, &local_err);
+    g_assert(!local_err);
+
+    /* read from s_local_disk (0, IMG_SIZE / 2) */
+    test_blk_read(top_blk, 0x33, 0, IMG_SIZE / 2,
+                  0, IMG_SIZE / 2, false);
+
+
+    /* read from s_local_disk (IMG_SIZE / 2, IMG_SIZE) */
+    test_blk_read(top_blk, 0x22, IMG_SIZE / 2,
+                  IMG_SIZE / 2, 0, IMG_SIZE, false);
+
+    teardown_secondary();
+}
+
 static void test_secondary_do_checkpoint(void)
 {
     BlockBackend *top_blk, *local_blk;
@@ -584,6 +634,8 @@ int main(int argc, char **argv)
     g_test_add_func("/replication/secondary/write", test_secondary_write);
     g_test_add_func("/replication/secondary/start", test_secondary_start);
     g_test_add_func("/replication/secondary/stop",  test_secondary_stop);
+    g_test_add_func("/replication/secondary/failover_then_ignore_requests",
+                    test_secondary_failover_then_ignore_requests);
     g_test_add_func("/replication/secondary/do_checkpoint",
                     test_secondary_do_checkpoint);
     g_test_add_func("/replication/secondary/get_error_all",
--
2.20.1

[Qemu-devel] [PATCH v5 3/4] net/filter.c: Add Options to insert filters anywhere in the filter list

[Lukas Straub]

To switch the Secondary to Primary, we need to insert new filters
before the filter-rewriter.

Add the options insert= and position= to be able to insert filters
anywhere in the filter list.

position should be "head" or "tail" to insert at the head or
tail of the filter list or it should be "id=<id>" to specify
the id of another filter.
insert should be either "before" or "behind" to specify where to
insert the new filter relative to the one specified with position.

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
---
 include/net/filter.h |  2 +
 net/filter.c         | 92 +++++++++++++++++++++++++++++++++++++++++++-
 qemu-options.hx      | 10 ++---
 3 files changed, 98 insertions(+), 6 deletions(-)

diff --git a/include/net/filter.h b/include/net/filter.h
index 49da666ac0..22a723305b 100644
--- a/include/net/filter.h
+++ b/include/net/filter.h
@@ -62,6 +62,8 @@ struct NetFilterState {
     NetClientState *netdev;
     NetFilterDirection direction;
     bool on;
+    char *position;
+    bool insert_before_flag;
     QTAILQ_ENTRY(NetFilterState) next;
 };

diff --git a/net/filter.c b/net/filter.c
index 28d1930db7..cd2ef9e979 100644
--- a/net/filter.c
+++ b/net/filter.c
@@ -171,11 +171,47 @@ static void netfilter_set_status(Object *obj, const char *str, Error **errp)
     }
 }

+static char *netfilter_get_position(Object *obj, Error **errp)
+{
+    NetFilterState *nf = NETFILTER(obj);
+
+    return g_strdup(nf->position);
+}
+
+static void netfilter_set_position(Object *obj, const char *str, Error **errp)
+{
+    NetFilterState *nf = NETFILTER(obj);
+
+    nf->position = g_strdup(str);
+}
+
+static char *netfilter_get_insert(Object *obj, Error **errp)
+{
+    NetFilterState *nf = NETFILTER(obj);
+
+    return nf->insert_before_flag ? g_strdup("before") : g_strdup("behind");
+}
+
+static void netfilter_set_insert(Object *obj, const char *str, Error **errp)
+{
+    NetFilterState *nf = NETFILTER(obj);
+
+    if (strcmp(str, "before") && strcmp(str, "behind")) {
+        error_setg(errp, "Invalid value for netfilter insert, "
+                         "should be 'before' or 'behind'");
+        return;
+    }
+
+    nf->insert_before_flag = !strcmp(str, "before");
+}
+
 static void netfilter_init(Object *obj)
 {
     NetFilterState *nf = NETFILTER(obj);

     nf->on = true;
+    nf->insert_before_flag = false;
+    nf->position = g_strdup("tail");

     object_property_add_str(obj, "netdev",
                             netfilter_get_netdev_id, netfilter_set_netdev_id,
@@ -187,11 +223,18 @@ static void netfilter_init(Object *obj)
     object_property_add_str(obj, "status",
                             netfilter_get_status, netfilter_set_status,
                             NULL);
+    object_property_add_str(obj, "position",
+                            netfilter_get_position, netfilter_set_position,
+                            NULL);
+    object_property_add_str(obj, "insert",
+                            netfilter_get_insert, netfilter_set_insert,
+                            NULL);
 }

 static void netfilter_complete(UserCreatable *uc, Error **errp)
 {
     NetFilterState *nf = NETFILTER(uc);
+    NetFilterState *position = NULL;
     NetClientState *ncs[MAX_QUEUE_NUM];
     NetFilterClass *nfc = NETFILTER_GET_CLASS(uc);
     int queues;
@@ -219,6 +262,41 @@ static void netfilter_complete(UserCreatable *uc, Error **errp)
         return;
     }

+    if (strcmp(nf->position, "head") && strcmp(nf->position, "tail")) {
+        Object *container;
+        Object *obj;
+        char *position_id;
+
+        if (!g_str_has_prefix(nf->position, "id=")) {
+            error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "position",
+                       "'head', 'tail' or 'id=<id>'");
+            return;
+        }
+
+        /* get the id from the string */
+        position_id = g_strndup(nf->position + 3, strlen(nf->position) - 3);
+
+        /* Search for the position to insert before/behind */
+        container = object_get_objects_root();
+        obj = object_resolve_path_component(container, position_id);
+        if (!obj) {
+            error_setg(errp, "filter '%s' not found", position_id);
+            g_free(position_id);
+            return;
+        }
+
+        position = NETFILTER(obj);
+
+        if (position->netdev != ncs[0]) {
+            error_setg(errp, "filter '%s' belongs to a different netdev",
+                        position_id);
+            g_free(position_id);
+            return;
+        }
+
+        g_free(position_id);
+    }
+
     nf->netdev = ncs[0];

     if (nfc->setup) {
@@ -228,7 +306,18 @@ static void netfilter_complete(UserCreatable *uc, Error **errp)
             return;
         }
     }
-    QTAILQ_INSERT_TAIL(&nf->netdev->filters, nf, next);
+
+    if (position) {
+        if (nf->insert_before_flag) {
+            QTAILQ_INSERT_BEFORE(position, nf, next);
+        } else {
+            QTAILQ_INSERT_AFTER(&nf->netdev->filters, position, nf, next);
+        }
+    } else if (!strcmp(nf->position, "head")) {
+        QTAILQ_INSERT_HEAD(&nf->netdev->filters, nf, next);
+    } else if (!strcmp(nf->position, "tail")) {
+        QTAILQ_INSERT_TAIL(&nf->netdev->filters, nf, next);
+    }
 }

 static void netfilter_finalize(Object *obj)
@@ -245,6 +334,7 @@ static void netfilter_finalize(Object *obj)
         QTAILQ_REMOVE(&nf->netdev->filters, nf, next);
     }
     g_free(nf->netdev_id);
+    g_free(nf->position);
 }

 static void default_handle_event(NetFilterState *nf, int event, Error **errp)
diff --git a/qemu-options.hx b/qemu-options.hx
index 08749a3391..23fa5a344e 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -4368,7 +4368,7 @@ applications, they can do this through this parameter. Its format is
 a gnutls priority string as described at
 @url{https://gnutls.org/manual/html_node/Priority-Strings.html}.

-@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}]
+@item -object filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{all|rx|tx}][,status=@var{on|off}][,position=@var{head|tail|id=<id>}][,insert=@var{behind|before}]

 Interval @var{t} can't be 0, this filter batches the packet delivery: all
 packets arriving in a given interval on netdev @var{netdevid} are delayed
@@ -4387,11 +4387,11 @@ queue @var{all|rx|tx} is an option that can be applied to any netfilter.
 @option{tx}: the filter is attached to the transmit queue of the netdev,
              where it will receive packets sent by the netdev.

-@item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support]
+@item -object filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support][,position=@var{head|tail|id=<id>}][,insert=@var{behind|before}]

 filter-mirror on netdev @var{netdevid},mirror net packet to chardev@var{chardevid}, if it has the vnet_hdr_support flag, filter-mirror will mirror packet with vnet_hdr_len.

-@item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support]
+@item -object filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support][,position=@var{head|tail|id=<id>}][,insert=@var{behind|before}]

 filter-redirector on netdev @var{netdevid},redirect filter's net packet to chardev
 @var{chardevid},and redirect indev's packet to filter.if it has the vnet_hdr_support flag,
@@ -4400,7 +4400,7 @@ Create a filter-redirector we need to differ outdev id from indev id, id can not
 be the same. we can just use indev or outdev, but at least one of indev or outdev
 need to be specified.

-@item -object filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_hdr_support]
+@item -object filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_hdr_support][,position=@var{head|tail|id=<id>}][,insert=@var{behind|before}]

 Filter-rewriter is a part of COLO project.It will rewrite tcp packet to
 secondary from primary to keep secondary tcp connection,and rewrite
@@ -4413,7 +4413,7 @@ colo secondary:
 -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
 -object filter-rewriter,id=rew0,netdev=hn0,queue=all

-@item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}]
+@item -object filter-dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{len}][,position=@var{head|tail|id=<id>}][,insert=@var{behind|before}]

 Dump the network traffic on netdev @var{dev} to the file specified by
 @var{filename}. At most @var{len} bytes (64k by default) per packet are stored.
--
2.20.1

[Qemu-devel] [PATCH v5 4/4] colo: Update Documentation for continuous replication

[Lukas Straub]

Document the qemu command-line and qmp commands for continuous replication

Signed-off-by: Lukas Straub <lukasstraub2@web.de>
---
 docs/COLO-FT.txt           | 212 +++++++++++++++++++++++++++----------
 docs/block-replication.txt |  28 +++--
 2 files changed, 173 insertions(+), 67 deletions(-)

diff --git a/docs/COLO-FT.txt b/docs/COLO-FT.txt
index ad24680d13..e98c95ca2b 100644
--- a/docs/COLO-FT.txt
+++ b/docs/COLO-FT.txt
@@ -145,35 +145,65 @@ The diagram just shows the main qmp command, you can get the detail
 in test procedure.
 
 == Test procedure ==
-1. Startup qemu
-Primary:
-# qemu-system-x86_64 -accel kvm -m 2048 -smp 2 -qmp stdio -name primary \
-  -device piix3-usb-uhci -vnc :7 \
-  -device usb-tablet -netdev tap,id=hn0,vhost=off \
-  -device virtio-net-pci,id=net-pci0,netdev=hn0 \
-  -drive if=virtio,id=primary-disk0,driver=quorum,read-pattern=fifo,vote-threshold=1,\
-         children.0.file.filename=1.raw,\
-         children.0.driver=raw -S
-Secondary:
-# qemu-system-x86_64 -accel kvm -m 2048 -smp 2 -qmp stdio -name secondary \
-  -device piix3-usb-uhci -vnc :7 \
-  -device usb-tablet -netdev tap,id=hn0,vhost=off \
-  -device virtio-net-pci,id=net-pci0,netdev=hn0 \
-  -drive if=none,id=secondary-disk0,file.filename=1.raw,driver=raw,node-name=node0 \
-  -drive if=virtio,id=active-disk0,driver=replication,mode=secondary,\
-         file.driver=qcow2,top-id=active-disk0,\
-         file.file.filename=/mnt/ramfs/active_disk.img,\
-         file.backing.driver=qcow2,\
-         file.backing.file.filename=/mnt/ramfs/hidden_disk.img,\
-         file.backing.backing=secondary-disk0 \
-  -incoming tcp:0:8888
-
-2. On Secondary VM's QEMU monitor, issue command
+Note: Here we are running both instances on the same Machine for testing,
+change the IP Addresses if you want to run it on two Hosts
+
+== Startup qemu ==
+1. Primary:
+# imagefolder="/mnt/vms/colo-test"
+
+The disks for the primary and secondary need to be the same before starting colo
+# cp --reflink=auto $imagefolder/primary.qcow2 $imagefolder/primary-copy.qcow2
+
+# qemu-system-x86_64 -enable-kvm -cpu qemu64,+kvmclock -m 512 -smp 1 -qmp stdio \
+   -vnc :0 -device piix3-usb-uhci -device usb-tablet -name primary \
+   -netdev tap,id=hn0,vhost=off,helper=/usr/lib/qemu/qemu-bridge-helper \
+   -device rtl8139,id=e0,netdev=hn0 \
+   -chardev socket,id=mirror0,host=127.0.0.1,port=9003,server,nowait \
+   -chardev socket,id=compare1,host=127.0.0.1,port=9004,server,wait \
+   -chardev socket,id=compare0,host=127.0.0.1,port=9001,server,nowait \
+   -chardev socket,id=compare0-0,host=127.0.0.1,port=9001 \
+   -chardev socket,id=compare_out,host=127.0.0.1,port=9005,server,nowait \
+   -chardev socket,id=compare_out0,host=127.0.0.1,port=9005 \
+   -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 \
+   -object filter-redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out \
+   -object filter-redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 \
+   -object iothread,id=iothread1 \
+   -object colo-compare,id=comp0,primary_in=compare0-0,secondary_in=compare1,\
+outdev=compare_out0,iothread=iothread1 \
+   -drive if=ide,id=colo-disk0,driver=quorum,read-pattern=fifo,vote-threshold=1,\
+children.0.file.filename=$imagefolder/primary.qcow2,children.0.driver=qcow2 -S
+
+2. Secondary:
+# imagefolder="/mnt/vms/colo-test"
+
+# qemu-img create -f qcow2 $imagefolder/secondary-active.qcow2 10G
+
+# qemu-img create -f qcow2 $imagefolder/secondary-hidden.qcow2 10G
+
+# qemu-system-x86_64 -enable-kvm -cpu qemu64,+kvmclock -m 512 -smp 1 -qmp stdio \
+   -vnc :1 -device piix3-usb-uhci -device usb-tablet -name secondary \
+   -netdev tap,id=hn0,vhost=off,helper=/usr/lib/qemu/qemu-bridge-helper \
+   -device rtl8139,id=e0,netdev=hn0 \
+   -chardev socket,id=red0,host=127.0.0.1,port=9003,reconnect=1 \
+   -chardev socket,id=red1,host=127.0.0.1,port=9004,reconnect=1 \
+   -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 \
+   -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 \
+   -object filter-rewriter,id=rew0,netdev=hn0,queue=all \
+   -drive if=none,id=parent0,file.filename=$imagefolder/primary-copy.qcow2,driver=qcow2 \
+   -drive if=none,id=childs0,driver=replication,mode=secondary,file.driver=qcow2,\
+top-id=childs0,file.file.filename=$imagefolder/secondary-active.qcow2,\
+file.backing.driver=qcow2,file.backing.file.filename=$imagefolder/secondary-hidden.qcow2,\
+file.backing.backing=parent0 \
+   -drive if=ide,id=colo-disk0,driver=quorum,read-pattern=fifo,vote-threshold=1,\
+children.0=childs0 \
+   -incoming tcp:0:9998
+
+
+3. On Secondary VM's QEMU monitor, issue command
 {'execute':'qmp_capabilities'}
-{ 'execute': 'nbd-server-start',
-  'arguments': {'addr': {'type': 'inet', 'data': {'host': 'xx.xx.xx.xx', 'port': '8889'} } }
-}
-{'execute': 'nbd-server-add', 'arguments': {'device': 'secondary-disk0', 'writable': true } }
+{'execute': 'nbd-server-start', 'arguments': {'addr': {'type': 'inet', 'data': {'host': '127.0.0.1', 'port': '9999'} } } }
+{'execute': 'nbd-server-add', 'arguments': {'device': 'parent0', 'writable': true } }
 
 Note:
   a. The qmp command nbd-server-start and nbd-server-add must be run
@@ -182,44 +212,112 @@ Note:
      same.
   c. It is better to put active disk and hidden disk in ramdisk.
 
-3. On Primary VM's QEMU monitor, issue command:
+4. On Primary VM's QEMU monitor, issue command:
 {'execute':'qmp_capabilities'}
-{ 'execute': 'human-monitor-command',
-  'arguments': {'command-line': 'drive_add -n buddy driver=replication,mode=primary,file.driver=nbd,file.host=xx.xx.xx.xx,file.port=8889,file.export=secondary-disk0,node-name=nbd_client0'}}
-{ 'execute':'x-blockdev-change', 'arguments':{'parent': 'primary-disk0', 'node': 'nbd_client0' } }
-{ 'execute': 'migrate-set-capabilities',
-      'arguments': {'capabilities': [ {'capability': 'x-colo', 'state': true } ] } }
-{ 'execute': 'migrate', 'arguments': {'uri': 'tcp:xx.xx.xx.xx:8888' } }
+{'execute': 'human-monitor-command', 'arguments': {'command-line': 'drive_add -n buddy driver=replication,mode=primary,file.driver=nbd,file.host=127.0.0.1,file.port=9999,file.export=parent0,node-name=replication0'}}
+{'execute': 'x-blockdev-change', 'arguments':{'parent': 'colo-disk0', 'node': 'replication0' } }
+{'execute': 'migrate-set-capabilities', 'arguments': {'capabilities': [ {'capability': 'x-colo', 'state': true } ] } }
+{'execute': 'migrate', 'arguments': {'uri': 'tcp:127.0.0.1:9998' } }
 
   Note:
   a. There should be only one NBD Client for each primary disk.
-  b. xx.xx.xx.xx is the secondary physical machine's hostname or IP
-  c. The qmp command line must be run after running qmp command line in
+  b. The qmp command line must be run after running qmp command line in
      secondary qemu.
 
-4. After the above steps, you will see, whenever you make changes to PVM, SVM will be synced.
+5. After the above steps, you will see, whenever you make changes to PVM, SVM will be synced.
 You can issue command '{ "execute": "migrate-set-parameters" , "arguments":{ "x-checkpoint-delay": 2000 } }'
-to change the checkpoint period time
+to change the idle checkpoint period time
+
+6. Failover test
+You can kill one of the VMs and Failover on the surviving VM:
+
+If you killed the Secondary, then follow "Primary Failover". After that,
+if you want to resume the replication, follow "Primary resume replication"
+
+If you killed the Primary, then follow "Secondary Failover". After that,
+if you want to resume the replication, follow "Secondary resume replication"
+
+== Primary Failover ==
+The Secondary died, resume on the Primary
+
+{'execute': 'x-blockdev-change', 'arguments':{ 'parent': 'colo-disk0', 'child': 'children.1'} }
+{'execute': 'human-monitor-command', 'arguments':{ 'command-line': 'drive_del replication0' } }
+{'execute': 'object-del', 'arguments':{ 'id': 'comp0' } }
+{'execute': 'object-del', 'arguments':{ 'id': 'iothread1' } }
+{'execute': 'object-del', 'arguments':{ 'id': 'm0' } }
+{'execute': 'object-del', 'arguments':{ 'id': 'redire0' } }
+{'execute': 'object-del', 'arguments':{ 'id': 'redire1' } }
+{'execute': 'x-colo-lost-heartbeat' }
+
+== Secondary Failover ==
+The Primary died, resume on the Secondary and prepare to become the new Primary
+
+{'execute': 'nbd-server-stop'}
+{'execute': 'x-colo-lost-heartbeat'}
+
+{'execute': 'object-del', 'arguments':{ 'id': 'f2' } }
+{'execute': 'object-del', 'arguments':{ 'id': 'f1' } }
+{'execute': 'chardev-remove', 'arguments':{ 'id': 'red1' } }
+{'execute': 'chardev-remove', 'arguments':{ 'id': 'red0' } }
+
+{'execute': 'chardev-add', 'arguments':{ 'id': 'mirror0', 'backend': {'type': 'socket', 'data': {'addr': { 'type': 'inet', 'data': { 'host': '127.0.0.1', 'port': '9003' } }, 'server': true } } } }
+{'execute': 'chardev-add', 'arguments':{ 'id': 'compare1', 'backend': {'type': 'socket', 'data': {'addr': { 'type': 'inet', 'data': { 'host': '127.0.0.1', 'port': '9004' } }, 'server': true } } } }
+{'execute': 'chardev-add', 'arguments':{ 'id': 'compare0', 'backend': {'type': 'socket', 'data': {'addr': { 'type': 'inet', 'data': { 'host': '127.0.0.1', 'port': '9001' } }, 'server': true } } } }
+{'execute': 'chardev-add', 'arguments':{ 'id': 'compare0-0', 'backend': {'type': 'socket', 'data': {'addr': { 'type': 'inet', 'data': { 'host': '127.0.0.1', 'port': '9001' } }, 'server': false } } } }
+{'execute': 'chardev-add', 'arguments':{ 'id': 'compare_out', 'backend': {'type': 'socket', 'data': {'addr': { 'type': 'inet', 'data': { 'host': '127.0.0.1', 'port': '9005' } }, 'server': true } } } }
+{'execute': 'chardev-add', 'arguments':{ 'id': 'compare_out0', 'backend': {'type': 'socket', 'data': {'addr': { 'type': 'inet', 'data': { 'host': '127.0.0.1', 'port': '9005' } }, 'server': false } } } }
+
+== Primary resume replication ==
+Resume replication after new Secondary is up.
+
+Start the new Secondary (Steps 2 and 3 above), then:
+{'execute': 'drive-mirror', 'arguments':{ 'device': 'colo-disk0', 'job-id': 'resync', 'target': 'nbd://127.0.0.1:9999/parent0', 'mode': 'existing', 'format': 'raw', 'sync': 'full'} }
+
+Wait until disk is synced, then:
+{'execute': 'stop'}
+{'execute': 'block-job-cancel', 'arguments':{ 'device': 'resync'} }
+
+{'execute': 'human-monitor-command', 'arguments':{ 'command-line': 'drive_add -n buddy driver=replication,mode=primary,file.driver=nbd,file.host=127.0.0.1,file.port=9999,file.export=parent0,node-name=replication0'}}
+{'execute': 'x-blockdev-change', 'arguments':{ 'parent': 'colo-disk0', 'node': 'replication0' } }
+
+{'execute': 'object-add', 'arguments':{ 'qom-type': 'filter-mirror', 'id': 'm0', 'props': { 'netdev': 'hn0', 'queue': 'tx', 'outdev': 'mirror0' } } }
+{'execute': 'object-add', 'arguments':{ 'qom-type': 'filter-redirector', 'id': 'redire0', 'props': { 'netdev': 'hn0', 'queue': 'rx', 'indev': 'compare_out' } } }
+{'execute': 'object-add', 'arguments':{ 'qom-type': 'filter-redirector', 'id': 'redire1', 'props': { 'netdev': 'hn0', 'queue': 'rx', 'outdev': 'compare0' } } }
+{'execute': 'object-add', 'arguments':{ 'qom-type': 'iothread', 'id': 'iothread1' } }
+{'execute': 'object-add', 'arguments':{ 'qom-type': 'colo-compare', 'id': 'comp0', 'props': { 'primary_in': 'compare0-0', 'secondary_in': 'compare1', 'outdev': 'compare_out0', 'iothread': 'iothread1' } } }
+
+{'execute': 'migrate-set-capabilities', 'arguments':{ 'capabilities': [ {'capability': 'x-colo', 'state': true } ] } }
+{'execute': 'migrate', 'arguments':{ 'uri': 'tcp:127.0.0.1:9998' } }
+
+Note:
+If this Primary previously was a Secondary, then we need to insert the
+filters before the filter-rewriter by using the
+"'insert': 'before', 'position': 'rew0'" Options. See below.
+
+== Secondary resume replication ==
+Become Primary and resume replication after new Secondary is up.
+
+Start the new Secondary (Steps 2 and 3 above, but with different image than
+primary-copy.qcow2 and different VNC port), then:
+{'execute': 'drive-mirror', 'arguments':{ 'device': 'colo-disk0', 'job-id': 'resync', 'target': 'nbd://127.0.0.1:9999/parent0', 'mode': 'existing', 'format': 'raw', 'sync': 'full'} }
+
+Wait until disk is synced, then:
+{'execute': 'stop'}
+{'execute': 'block-job-cancel', 'arguments':{ 'device': 'resync' } }
 
-5. Failover test
-You can kill Primary VM and run 'x_colo_lost_heartbeat' in Secondary VM's
-monitor at the same time, then SVM will failover and client will not detect this
-change.
+{'execute': 'human-monitor-command', 'arguments':{ 'command-line': 'drive_add -n buddy driver=replication,mode=primary,file.driver=nbd,file.host=127.0.0.1,file.port=9999,file.export=parent0,node-name=replication0'}}
+{'execute': 'x-blockdev-change', 'arguments':{ 'parent': 'colo-disk0', 'node': 'replication0' } }
 
-Before issuing '{ "execute": "x-colo-lost-heartbeat" }' command, we have to
-issue block related command to stop block replication.
-Primary:
-  Remove the nbd child from the quorum:
-  { 'execute': 'x-blockdev-change', 'arguments': {'parent': 'colo-disk0', 'child': 'children.1'}}
-  { 'execute': 'human-monitor-command','arguments': {'command-line': 'drive_del blk-buddy0'}}
-  Note: there is no qmp command to remove the blockdev now
+{'execute': 'object-add', 'arguments':{ 'qom-type': 'filter-mirror', 'id': 'm0', 'props': { 'insert': 'before', 'position': 'id=rew0', 'netdev': 'hn0', 'queue': 'tx', 'outdev': 'mirror0' } } }
+{'execute': 'object-add', 'arguments':{ 'qom-type': 'filter-redirector', 'id': 'redire0', 'props': { 'insert': 'before', 'position': 'id=rew0', 'netdev': 'hn0', 'queue': 'rx', 'indev': 'compare_out' } } }
+{'execute': 'object-add', 'arguments':{ 'qom-type': 'filter-redirector', 'id': 'redire1', 'props': { 'insert': 'before', 'position': 'id=rew0', 'netdev': 'hn0', 'queue': 'rx', 'outdev': 'compare0' } } }
+{'execute': 'object-add', 'arguments':{ 'qom-type': 'iothread', 'id': 'iothread1' } }
+{'execute': 'object-add', 'arguments':{ 'qom-type': 'colo-compare', 'id': 'comp0', 'props': { 'primary_in': 'compare0-0', 'secondary_in': 'compare1', 'outdev': 'compare_out0', 'iothread': 'iothread1' } } }
 
-Secondary:
-  The primary host is down, so we should do the following thing:
-  { 'execute': 'nbd-server-stop' }
+{'execute': 'migrate-set-capabilities', 'arguments':{ 'capabilities': [ {'capability': 'x-colo', 'state': true } ] } }
+{'execute': 'migrate', 'arguments':{ 'uri': 'tcp:127.0.0.1:9998' } }
 
 == TODO ==
-1. Support continuous VM replication.
-2. Support shared storage.
-3. Develop the heartbeat part.
-4. Reduce checkpoint VM’s downtime while doing checkpoint.
+1. Support shared storage.
+2. Develop the heartbeat part.
+3. Reduce checkpoint VM’s downtime while doing checkpoint.
diff --git a/docs/block-replication.txt b/docs/block-replication.txt
index 6bde6737fb..108e9166a8 100644
--- a/docs/block-replication.txt
+++ b/docs/block-replication.txt
@@ -65,12 +65,12 @@ blocks that are already in QEMU.
              ^            ||                            .----------
              |            ||                            | Secondary
         1 Quorum          ||                            '----------
-         /      \         ||
-        /        \        ||
-   Primary    2 filter
-     disk         ^                                                             virtio-blk
-                  |                                                                  ^
-                3 NBD  ------->  3 NBD                                               |
+         /      \         ||                                                           virtio-blk
+        /        \        ||                                                               ^
+   Primary    2 filter                                                                     |
+     disk         ^                                                                   7 Quorum
+                  |                                                                    /
+                3 NBD  ------->  3 NBD                                                /
                 client    ||     server                                          2 filter
                           ||        ^                                                ^
 --------.                 ||        |                                                |
@@ -106,6 +106,10 @@ any state that would otherwise be lost by the speculative write-through
 of the NBD server into the secondary disk. So before block replication,
 the primary disk and secondary disk should contain the same data.
 
+7) The secondary also has a quorum node, so after secondary failover it
+can become the new primary and continue replication.
+
+
 == Failure Handling ==
 There are 7 internal errors when block replication is running:
 1. I/O error on primary disk
@@ -171,16 +175,18 @@ Primary:
      leading whitespace.
   5. The qmp command line must be run after running qmp command line in
      secondary qemu.
-  6. After failover we need remove children.1 (replication driver).
+  6. After primary failover we need remove children.1 (replication driver).
 
 Secondary:
   -drive if=none,driver=raw,file.filename=1.raw,id=colo1 \
-  -drive if=xxx,id=topxxx,driver=replication,mode=secondary,top-id=topxxx\
+  -drive if=none,id=childs1,driver=replication,mode=secondary,top-id=childs1
          file.file.filename=active_disk.qcow2,\
          file.driver=qcow2,\
          file.backing.file.filename=hidden_disk.qcow2,\
          file.backing.driver=qcow2,\
          file.backing.backing=colo1
+  -drive if=xxx,driver=quorum,read-pattern=fifo,id=top-disk1,\
+         vote-threshold=1,children.0=childs1
 
   Then run qmp command in secondary qemu:
     { 'execute': 'nbd-server-start',
@@ -234,6 +240,8 @@ Secondary:
   The primary host is down, so we should do the following thing:
   { 'execute': 'nbd-server-stop' }
 
+Promote Secondary to Primary:
+  see COLO-FT.txt
+
 TODO:
-1. Continuous block replication
-2. Shared disk
+1. Shared disk
-- 
2.20.1

Re: [PATCH v5 0/4] colo: Add support for continuous replication

[Lukas Straub]

On Sun, 15 Sep 2019 21:19:50 +0200
Lukas Straub <lukasstraub2@web.de> wrote:

> Hello Everyone,
> These Patches add support for continuous replication to colo. This means
> that after the Primary fails and the Secondary did a failover, the Secondary
> can then become Primary and resume replication to a new Secondary.
>
> On a side note, I wrote a Pacemaker Resource Agent for colo which I will
> post when its ready.
> I have to say it's quite fun to randomly kill a Node, wait for resync
> and repeat and see how the VM stays alive all the time. :)
>
> Regards,
> Lukas Straub
>
> v5:
>  - change syntax for the position= parameter
>  - fix spelling mistake
>
> v4:
>  - fix checkpatch.pl warnings
>
> v3:
>  - add test for replication changes
>  - check if the filter to be inserted before/behind belongs to the same interface
>  - fix the error message for the position= parameter
>  - rename term "after" -> "behind" and variable "insert_before" -> "insert_before_flag"
>  - document the quorum node on the secondary side
>  - simplify quorum parameters in documentation
>  - remove trailing spaces in documentation
>  - clarify the testing procedure in documentation
>
> v2:
>  - fix email formating
>  - fix checkpatch.pl warnings
>  - fix patchew error
>  - clearer commit messages
>
>
> Lukas Straub (4):
>   block/replication.c: Ignore requests after failover
>   tests/test-replication.c: Add test for ignoring requests after
>     failover
>   net/filter.c: Add Options to insert filters anywhere in the filter
>     list
>   colo: Update Documentation for continuous replication
>
>  block/replication.c        |  38 ++++++-
>  docs/COLO-FT.txt           | 212 +++++++++++++++++++++++++++----------
>  docs/block-replication.txt |  28 +++--
>  include/net/filter.h       |   2 +
>  net/filter.c               |  92 +++++++++++++++-
>  qemu-options.hx            |  10 +-
>  tests/test-replication.c   |  52 +++++++++
>  7 files changed, 358 insertions(+), 76 deletions(-)
>

Hello Everyone,
Ping.

Regards,
Lukas Straub

RE: [PATCH v5 0/4] colo: Add support for continuous replication

[Zhang, Chen]

> -----Original Message-----
> From: Lukas Straub <lukasstraub2@web.de>
> Sent: Friday, September 27, 2019 12:10 AM
> To: qemu-devel <qemu-devel@nongnu.org>
> Cc: Zhang, Chen <chen.zhang@intel.com>; Jason Wang
> <jasowang@redhat.com>; Wen Congyang <wencongyang2@huawei.com>;
> Xie Changlong <xiechanglong.d@gmail.com>; kwolf@redhat.com;
> mreitz@redhat.com
> Subject: Re: [PATCH v5 0/4] colo: Add support for continuous replication
> 
> On Sun, 15 Sep 2019 21:19:50 +0200
> Lukas Straub <lukasstraub2@web.de> wrote:
> 
> > Hello Everyone,
> > These Patches add support for continuous replication to colo. This
> > means that after the Primary fails and the Secondary did a failover,
> > the Secondary can then become Primary and resume replication to a new
> Secondary.
> >
> > On a side note, I wrote a Pacemaker Resource Agent for colo which I
> > will post when its ready.
> > I have to say it's quite fun to randomly kill a Node, wait for resync
> > and repeat and see how the VM stays alive all the time. :)
> >
> > Regards,
> > Lukas Straub
> >
> > v5:
> >  - change syntax for the position= parameter
> >  - fix spelling mistake
> >
> > v4:
> >  - fix checkpatch.pl warnings
> >
> > v3:
> >  - add test for replication changes
> >  - check if the filter to be inserted before/behind belongs to the
> > same interface
> >  - fix the error message for the position= parameter
> >  - rename term "after" -> "behind" and variable "insert_before" ->
> "insert_before_flag"
> >  - document the quorum node on the secondary side
> >  - simplify quorum parameters in documentation
> >  - remove trailing spaces in documentation
> >  - clarify the testing procedure in documentation
> >
> > v2:
> >  - fix email formating
> >  - fix checkpatch.pl warnings
> >  - fix patchew error
> >  - clearer commit messages
> >
> >
> > Lukas Straub (4):
> >   block/replication.c: Ignore requests after failover
> >   tests/test-replication.c: Add test for ignoring requests after
> >     failover
> >   net/filter.c: Add Options to insert filters anywhere in the filter
> >     list
> >   colo: Update Documentation for continuous replication
> >
> >  block/replication.c        |  38 ++++++-
> >  docs/COLO-FT.txt           | 212 +++++++++++++++++++++++++++----------
> >  docs/block-replication.txt |  28 +++--
> >  include/net/filter.h       |   2 +
> >  net/filter.c               |  92 +++++++++++++++-
> >  qemu-options.hx            |  10 +-
> >  tests/test-replication.c   |  52 +++++++++
> >  7 files changed, 358 insertions(+), 76 deletions(-)
> >
> 
> Hello Everyone,
> Ping.

Sorry for slow reply, I'm reviewing~

Thanks
Zhang Chen

> 
> Regards,
> Lukas Straub

RE: [PATCH v5 1/4] block/replication.c: Ignore requests after failover

[Zhang, Chen]

> -----Original Message-----
> From: Lukas Straub <lukasstraub2@web.de>
> Sent: Monday, September 16, 2019 3:20 AM
> To: qemu-devel <qemu-devel@nongnu.org>
> Cc: Zhang, Chen <chen.zhang@intel.com>; Jason Wang
> <jasowang@redhat.com>; Wen Congyang <wencongyang2@huawei.com>;
> Xie Changlong <xiechanglong.d@gmail.com>; kwolf@redhat.com;
> mreitz@redhat.com
> Subject: [PATCH v5 1/4] block/replication.c: Ignore requests after failover
> 
> After failover the Secondary side of replication shouldn't change state,
> because it now functions as our primary disk.
> 
> In replication_start, replication_do_checkpoint, replication_stop, ignore the
> request if current state is BLOCK_REPLICATION_DONE (sucessful failover) or
> BLOCK_REPLICATION_FAILOVER (failover in progres i.e. currently merging
> active and hidden images into the base image).
> 

It looks good for me, and this patch works well in COLO continuous backup status in my tests.
Reviewed-by: Zhang Chen <chen.zhang@intel.com>

But I think this patch still need reviewed by Xie Changlong  or  Kevin Wolf.

Thanks
Zhang Chen

> Signed-off-by: Lukas Straub <lukasstraub2@web.de>
> ---
>  block/replication.c | 38 +++++++++++++++++++++++++++++++++++---
>  1 file changed, 35 insertions(+), 3 deletions(-)
> 
> diff --git a/block/replication.c b/block/replication.c index
> 3d4dedddfc..97cc65c0cf 100644
> --- a/block/replication.c
> +++ b/block/replication.c
> @@ -454,6 +454,17 @@ static void replication_start(ReplicationState *rs,
> ReplicationMode mode,
>      aio_context_acquire(aio_context);
>      s = bs->opaque;
> 
> +    if (s->stage == BLOCK_REPLICATION_DONE ||
> +        s->stage == BLOCK_REPLICATION_FAILOVER) {
> +        /*
> +         * This case happens when a secondary is promoted to primary.
> +         * Ignore the request because the secondary side of replication
> +         * doesn't have to do anything anymore.
> +         */
> +        aio_context_release(aio_context);
> +        return;
> +    }
> +
>      if (s->stage != BLOCK_REPLICATION_NONE) {
>          error_setg(errp, "Block replication is running or done");
>          aio_context_release(aio_context); @@ -529,8 +540,7 @@ static void
> replication_start(ReplicationState *rs, ReplicationMode mode,
>                     "Block device is in use by internal backup job");
> 
>          top_bs = bdrv_lookup_bs(s->top_id, s->top_id, NULL);
> -        if (!top_bs || !bdrv_is_root_node(top_bs) ||
> -            !check_top_bs(top_bs, bs)) {
> +        if (!top_bs || !check_top_bs(top_bs, bs)) {
>              error_setg(errp, "No top_bs or it is invalid");
>              reopen_backing_file(bs, false, NULL);
>              aio_context_release(aio_context); @@ -577,6 +587,17 @@ static void
> replication_do_checkpoint(ReplicationState *rs, Error **errp)
>      aio_context_acquire(aio_context);
>      s = bs->opaque;
> 
> +    if (s->stage == BLOCK_REPLICATION_DONE ||
> +        s->stage == BLOCK_REPLICATION_FAILOVER) {
> +        /*
> +         * This case happens when a secondary was promoted to primary.
> +         * Ignore the request because the secondary side of replication
> +         * doesn't have to do anything anymore.
> +         */
> +        aio_context_release(aio_context);
> +        return;
> +    }
> +
>      if (s->mode == REPLICATION_MODE_SECONDARY) {
>          secondary_do_checkpoint(s, errp);
>      }
> @@ -593,7 +614,7 @@ static void replication_get_error(ReplicationState *rs,
> Error **errp)
>      aio_context_acquire(aio_context);
>      s = bs->opaque;
> 
> -    if (s->stage != BLOCK_REPLICATION_RUNNING) {
> +    if (s->stage == BLOCK_REPLICATION_NONE) {
>          error_setg(errp, "Block replication is not running");
>          aio_context_release(aio_context);
>          return;
> @@ -635,6 +656,17 @@ static void replication_stop(ReplicationState *rs,
> bool failover, Error **errp)
>      aio_context_acquire(aio_context);
>      s = bs->opaque;
> 
> +    if (s->stage == BLOCK_REPLICATION_DONE ||
> +        s->stage == BLOCK_REPLICATION_FAILOVER) {
> +        /*
> +         * This case happens when a secondary was promoted to primary.
> +         * Ignore the request because the secondary side of replication
> +         * doesn't have to do anything anymore.
> +         */
> +        aio_context_release(aio_context);
> +        return;
> +    }
> +
>      if (s->stage != BLOCK_REPLICATION_RUNNING) {
>          error_setg(errp, "Block replication is not running");
>          aio_context_release(aio_context);
> --
> 2.20.1

RE: [PATCH v5 3/4] net/filter.c: Add Options to insert filters anywhere in the filter list

[Zhang, Chen]

> -----Original Message-----
> From: Lukas Straub <lukasstraub2@web.de>
> Sent: Monday, September 16, 2019 3:20 AM
> To: qemu-devel <qemu-devel@nongnu.org>
> Cc: Zhang, Chen <chen.zhang@intel.com>; Jason Wang
> <jasowang@redhat.com>; Wen Congyang <wencongyang2@huawei.com>;
> Xie Changlong <xiechanglong.d@gmail.com>; kwolf@redhat.com;
> mreitz@redhat.com
> Subject: [PATCH v5 3/4] net/filter.c: Add Options to insert filters anywhere in
> the filter list
> 
> To switch the Secondary to Primary, we need to insert new filters before the
> filter-rewriter.
> 
> Add the options insert= and position= to be able to insert filters anywhere in
> the filter list.
> 
> position should be "head" or "tail" to insert at the head or tail of the filter list
> or it should be "id=<id>" to specify the id of another filter.
> insert should be either "before" or "behind" to specify where to insert the
> new filter relative to the one specified with position.
> 
> Signed-off-by: Lukas Straub <lukasstraub2@web.de>
> ---
>  include/net/filter.h |  2 +
>  net/filter.c         | 92
> +++++++++++++++++++++++++++++++++++++++++++-
>  qemu-options.hx      | 10 ++---
>  3 files changed, 98 insertions(+), 6 deletions(-)
> 
> diff --git a/include/net/filter.h b/include/net/filter.h index
> 49da666ac0..22a723305b 100644
> --- a/include/net/filter.h
> +++ b/include/net/filter.h
> @@ -62,6 +62,8 @@ struct NetFilterState {
>      NetClientState *netdev;
>      NetFilterDirection direction;
>      bool on;
> +    char *position;
> +    bool insert_before_flag;
>      QTAILQ_ENTRY(NetFilterState) next;
>  };
> 
> diff --git a/net/filter.c b/net/filter.c index 28d1930db7..cd2ef9e979 100644
> --- a/net/filter.c
> +++ b/net/filter.c
> @@ -171,11 +171,47 @@ static void netfilter_set_status(Object *obj, const
> char *str, Error **errp)
>      }
>  }
> 
> +static char *netfilter_get_position(Object *obj, Error **errp) {
> +    NetFilterState *nf = NETFILTER(obj);
> +
> +    return g_strdup(nf->position);
> +}
> +
> +static void netfilter_set_position(Object *obj, const char *str, Error
> +**errp) {
> +    NetFilterState *nf = NETFILTER(obj);
> +
> +    nf->position = g_strdup(str);
> +}
> +
> +static char *netfilter_get_insert(Object *obj, Error **errp) {
> +    NetFilterState *nf = NETFILTER(obj);
> +
> +    return nf->insert_before_flag ? g_strdup("before") :
> +g_strdup("behind"); }
> +
> +static void netfilter_set_insert(Object *obj, const char *str, Error
> +**errp) {
> +    NetFilterState *nf = NETFILTER(obj);
> +
> +    if (strcmp(str, "before") && strcmp(str, "behind")) {
> +        error_setg(errp, "Invalid value for netfilter insert, "
> +                         "should be 'before' or 'behind'");
> +        return;
> +    }
> +
> +    nf->insert_before_flag = !strcmp(str, "before"); }
> +
>  static void netfilter_init(Object *obj)  {
>      NetFilterState *nf = NETFILTER(obj);
> 
>      nf->on = true;
> +    nf->insert_before_flag = false;
> +    nf->position = g_strdup("tail");
> 
>      object_property_add_str(obj, "netdev",
>                              netfilter_get_netdev_id, netfilter_set_netdev_id, @@ -
> 187,11 +223,18 @@ static void netfilter_init(Object *obj)
>      object_property_add_str(obj, "status",
>                              netfilter_get_status, netfilter_set_status,
>                              NULL);
> +    object_property_add_str(obj, "position",
> +                            netfilter_get_position, netfilter_set_position,
> +                            NULL);
> +    object_property_add_str(obj, "insert",
> +                            netfilter_get_insert, netfilter_set_insert,
> +                            NULL);
>  }
> 
>  static void netfilter_complete(UserCreatable *uc, Error **errp)  {
>      NetFilterState *nf = NETFILTER(uc);
> +    NetFilterState *position = NULL;
>      NetClientState *ncs[MAX_QUEUE_NUM];
>      NetFilterClass *nfc = NETFILTER_GET_CLASS(uc);
>      int queues;
> @@ -219,6 +262,41 @@ static void netfilter_complete(UserCreatable *uc,
> Error **errp)
>          return;
>      }
> 
> +    if (strcmp(nf->position, "head") && strcmp(nf->position, "tail")) {
> +        Object *container;
> +        Object *obj;
> +        char *position_id;
> +
> +        if (!g_str_has_prefix(nf->position, "id=")) {
> +            error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "position",
> +                       "'head', 'tail' or 'id=<id>'");
> +            return;
> +        }
> +
> +        /* get the id from the string */
> +        position_id = g_strndup(nf->position + 3, strlen(nf->position)
> + - 3);
> +
> +        /* Search for the position to insert before/behind */
> +        container = object_get_objects_root();
> +        obj = object_resolve_path_component(container, position_id);
> +        if (!obj) {
> +            error_setg(errp, "filter '%s' not found", position_id);
> +            g_free(position_id);
> +            return;
> +        }
> +
> +        position = NETFILTER(obj);
> +
> +        if (position->netdev != ncs[0]) {
> +            error_setg(errp, "filter '%s' belongs to a different netdev",
> +                        position_id);
> +            g_free(position_id);
> +            return;
> +        }
> +
> +        g_free(position_id);
> +    }
> +
>      nf->netdev = ncs[0];
> 
>      if (nfc->setup) {
> @@ -228,7 +306,18 @@ static void netfilter_complete(UserCreatable *uc,
> Error **errp)
>              return;
>          }
>      }
> -    QTAILQ_INSERT_TAIL(&nf->netdev->filters, nf, next);
> +
> +    if (position) {
> +        if (nf->insert_before_flag) {
> +            QTAILQ_INSERT_BEFORE(position, nf, next);
> +        } else {
> +            QTAILQ_INSERT_AFTER(&nf->netdev->filters, position, nf, next);
> +        }
> +    } else if (!strcmp(nf->position, "head")) {
> +        QTAILQ_INSERT_HEAD(&nf->netdev->filters, nf, next);
> +    } else if (!strcmp(nf->position, "tail")) {
> +        QTAILQ_INSERT_TAIL(&nf->netdev->filters, nf, next);
> +    }
>  }
> 
>  static void netfilter_finalize(Object *obj) @@ -245,6 +334,7 @@ static void
> netfilter_finalize(Object *obj)
>          QTAILQ_REMOVE(&nf->netdev->filters, nf, next);
>      }
>      g_free(nf->netdev_id);
> +    g_free(nf->position);
>  }
> 
>  static void default_handle_event(NetFilterState *nf, int event, Error **errp)
> diff --git a/qemu-options.hx b/qemu-options.hx index
> 08749a3391..23fa5a344e 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -4368,7 +4368,7 @@ applications, they can do this through this
> parameter. Its format is  a gnutls priority string as described at
> @url{https://gnutls.org/manual/html_node/Priority-Strings.html}.
> 
> -@item -object filter-
> buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{
> all|rx|tx}][,status=@var{on|off}]
> +@item -object
> +filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue
> +=@var{all|rx|tx}][,status=@var{on|off}][,position=@var{head|tail|id=<id
> +>}][,insert=@var{behind|before}]
> 
>  Interval @var{t} can't be 0, this filter batches the packet delivery: all  packets
> arriving in a given interval on netdev @var{netdevid} are delayed @@ -
> 4387,11 +4387,11 @@ queue @var{all|rx|tx} is an option that can be applied
> to any netfilter.
>  @option{tx}: the filter is attached to the transmit queue of the netdev,
>               where it will receive packets sent by the netdev.
> 
> -@item -object filter-
> mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue
> =@var{all|rx|tx}[,vnet_hdr_support]
> +@item -object
> +filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},
> +queue=@var{all|rx|tx}[,vnet_hdr_support][,position=@var{head|tail|id=<
> i
> +d>}][,insert=@var{behind|before}]
> 
>  filter-mirror on netdev @var{netdevid},mirror net packet to
> chardev@var{chardevid}, if it has the vnet_hdr_support flag, filter-mirror will
> mirror packet with vnet_hdr_len.
> 

Please add description for the newly added parameter in each filter.
After that:
Reviewed-by: Zhang Chen <chen.zhang@intel.com>

Thanks
Zhang Chen


> -@item -object filter-
> redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},out
> dev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support]
> +@item -object
> +filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevi
> +d},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support][,p
> os
> +ition=@var{head|tail|id=<id>}][,insert=@var{behind|before}]
> 
>  filter-redirector on netdev @var{netdevid},redirect filter's net packet to
> chardev  @var{chardevid},and redirect indev's packet to filter.if it has the
> vnet_hdr_support flag, @@ -4400,7 +4400,7 @@ Create a filter-redirector
> we need to differ outdev id from indev id, id can not  be the same. we can
> just use indev or outdev, but at least one of indev or outdev  need to be
> specified.
> 
> -@item -object filter-
> rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_
> hdr_support]
> +@item -object
> +filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx}
> +,[vnet_hdr_support][,position=@var{head|tail|id=<id>}][,insert=@var{beh
> +ind|before}]
> 
>  Filter-rewriter is a part of COLO project.It will rewrite tcp packet to
> secondary from primary to keep secondary tcp connection,and rewrite @@ -
> 4413,7 +4413,7 @@ colo secondary:
>  -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
>  -object filter-rewriter,id=rew0,netdev=hn0,queue=all
> 
> -@item -object filter-
> dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{
> len}]
> +@item -object
> +filter-
> dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=
> +@var{len}][,position=@var{head|tail|id=<id>}][,insert=@var{behind|befor
> +e}]
> 
>  Dump the network traffic on netdev @var{dev} to the file specified by
> @var{filename}. At most @var{len} bytes (64k by default) per packet are
> stored.
> --
> 2.20.1

RE: [PATCH v5 4/4] colo: Update Documentation for continuous replication

[Zhang, Chen]

> -----Original Message-----
> From: Lukas Straub <lukasstraub2@web.de>
> Sent: Monday, September 16, 2019 3:20 AM
> To: qemu-devel <qemu-devel@nongnu.org>
> Cc: Zhang, Chen <chen.zhang@intel.com>; Jason Wang
> <jasowang@redhat.com>; Wen Congyang <wencongyang2@huawei.com>;
> Xie Changlong <xiechanglong.d@gmail.com>; kwolf@redhat.com;
> mreitz@redhat.com
> Subject: [PATCH v5 4/4] colo: Update Documentation for continuous
> replication
> 
> Document the qemu command-line and qmp commands for continuous
> replication
> 
> Signed-off-by: Lukas Straub <lukasstraub2@web.de>
> ---
>  docs/COLO-FT.txt           | 212 +++++++++++++++++++++++++++----------
>  docs/block-replication.txt |  28 +++--
>  2 files changed, 173 insertions(+), 67 deletions(-)
> 
> diff --git a/docs/COLO-FT.txt b/docs/COLO-FT.txt index
> ad24680d13..e98c95ca2b 100644
> --- a/docs/COLO-FT.txt
> +++ b/docs/COLO-FT.txt
> @@ -145,35 +145,65 @@ The diagram just shows the main qmp command,
> you can get the detail  in test procedure.
> 
>  == Test procedure ==
> -1. Startup qemu
> -Primary:
> -# qemu-system-x86_64 -accel kvm -m 2048 -smp 2 -qmp stdio -name
> primary \
> -  -device piix3-usb-uhci -vnc :7 \
> -  -device usb-tablet -netdev tap,id=hn0,vhost=off \
> -  -device virtio-net-pci,id=net-pci0,netdev=hn0 \
> -  -drive if=virtio,id=primary-disk0,driver=quorum,read-pattern=fifo,vote-
> threshold=1,\
> -         children.0.file.filename=1.raw,\
> -         children.0.driver=raw -S
> -Secondary:
> -# qemu-system-x86_64 -accel kvm -m 2048 -smp 2 -qmp stdio -name
> secondary \
> -  -device piix3-usb-uhci -vnc :7 \
> -  -device usb-tablet -netdev tap,id=hn0,vhost=off \
> -  -device virtio-net-pci,id=net-pci0,netdev=hn0 \
> -  -drive if=none,id=secondary-disk0,file.filename=1.raw,driver=raw,node-
> name=node0 \
> -  -drive if=virtio,id=active-disk0,driver=replication,mode=secondary,\
> -         file.driver=qcow2,top-id=active-disk0,\
> -         file.file.filename=/mnt/ramfs/active_disk.img,\
> -         file.backing.driver=qcow2,\
> -         file.backing.file.filename=/mnt/ramfs/hidden_disk.img,\
> -         file.backing.backing=secondary-disk0 \
> -  -incoming tcp:0:8888
> -
> -2. On Secondary VM's QEMU monitor, issue command
> +Note: Here we are running both instances on the same Machine for
> +testing, change the IP Addresses if you want to run it on two Hosts
> +
> +== Startup qemu ==
> +1. Primary:
> +# imagefolder="/mnt/vms/colo-test"
> +
> +The disks for the primary and secondary need to be the same before
> +starting colo # cp --reflink=auto $imagefolder/primary.qcow2
> +$imagefolder/primary-copy.qcow2
> +
> +# qemu-system-x86_64 -enable-kvm -cpu qemu64,+kvmclock -m 512 -smp
> 1 -qmp stdio \
> +   -vnc :0 -device piix3-usb-uhci -device usb-tablet -name primary \
> +   -netdev tap,id=hn0,vhost=off,helper=/usr/lib/qemu/qemu-bridge-helper
> \
> +   -device rtl8139,id=e0,netdev=hn0 \
> +   -chardev socket,id=mirror0,host=127.0.0.1,port=9003,server,nowait \
> +   -chardev socket,id=compare1,host=127.0.0.1,port=9004,server,wait \
> +   -chardev socket,id=compare0,host=127.0.0.1,port=9001,server,nowait \
> +   -chardev socket,id=compare0-0,host=127.0.0.1,port=9001 \
> +   -chardev socket,id=compare_out,host=127.0.0.1,port=9005,server,nowait
> \
> +   -chardev socket,id=compare_out0,host=127.0.0.1,port=9005 \
> +   -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 \
> +   -object filter-
> redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out \
> +   -object filter-
> redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 \
> +   -object iothread,id=iothread1 \
> +   -object
> +colo-compare,id=comp0,primary_in=compare0-
> 0,secondary_in=compare1,\
> +outdev=compare_out0,iothread=iothread1 \
> +   -drive
> +if=ide,id=colo-disk0,driver=quorum,read-pattern=fifo,vote-threshold=1,\
> +children.0.file.filename=$imagefolder/primary.qcow2,children.0.driver=q
> +cow2 -S
> +
> +2. Secondary:
> +# imagefolder="/mnt/vms/colo-test"
> +
> +# qemu-img create -f qcow2 $imagefolder/secondary-active.qcow2 10G
> +
> +# qemu-img create -f qcow2 $imagefolder/secondary-hidden.qcow2 10G
> +
> +# qemu-system-x86_64 -enable-kvm -cpu qemu64,+kvmclock -m 512 -smp
> 1 -qmp stdio \
> +   -vnc :1 -device piix3-usb-uhci -device usb-tablet -name secondary \
> +   -netdev tap,id=hn0,vhost=off,helper=/usr/lib/qemu/qemu-bridge-helper
> \
> +   -device rtl8139,id=e0,netdev=hn0 \
> +   -chardev socket,id=red0,host=127.0.0.1,port=9003,reconnect=1 \
> +   -chardev socket,id=red1,host=127.0.0.1,port=9004,reconnect=1 \
> +   -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 \
> +   -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 \
> +   -object filter-rewriter,id=rew0,netdev=hn0,queue=all \
> +   -drive if=none,id=parent0,file.filename=$imagefolder/primary-
> copy.qcow2,driver=qcow2 \
> +   -drive
> +if=none,id=childs0,driver=replication,mode=secondary,file.driver=qcow2,
> +\
> +top-id=childs0,file.file.filename=$imagefolder/secondary-active.qcow2,\
> +file.backing.driver=qcow2,file.backing.file.filename=$imagefolder/secon
> +dary-hidden.qcow2,\
> +file.backing.backing=parent0 \
> +   -drive
> +if=ide,id=colo-disk0,driver=quorum,read-pattern=fifo,vote-threshold=1,\
> +children.0=childs0 \
> +   -incoming tcp:0:9998
> +

I know in your COLO test environment, all the node running in same physical machine,
but current COLO start parameter demo easy to misunderstand users.
I think we can introduce primary node as 192.168.1.1, secondary node as 192.168.1.2.
Same issue for the VM image, we should avoid the "primary-copy.qow2". 
Make two node independent is more clear. 



> +
> +3. On Secondary VM's QEMU monitor, issue command
>  {'execute':'qmp_capabilities'}
> -{ 'execute': 'nbd-server-start',
> -  'arguments': {'addr': {'type': 'inet', 'data': {'host': 'xx.xx.xx.xx', 'port':
> '8889'} } } -}
> -{'execute': 'nbd-server-add', 'arguments': {'device': 'secondary-disk0',
> 'writable': true } }
> +{'execute': 'nbd-server-start', 'arguments': {'addr': {'type': 'inet',
> +'data': {'host': '127.0.0.1', 'port': '9999'} } } }
> +{'execute': 'nbd-server-add', 'arguments': {'device': 'parent0',
> +'writable': true } }
> 
>  Note:
>    a. The qmp command nbd-server-start and nbd-server-add must be run
> @@ -182,44 +212,112 @@ Note:
>       same.
>    c. It is better to put active disk and hidden disk in ramdisk.
> 
> -3. On Primary VM's QEMU monitor, issue command:
> +4. On Primary VM's QEMU monitor, issue command:
>  {'execute':'qmp_capabilities'}
> -{ 'execute': 'human-monitor-command',
> -  'arguments': {'command-line': 'drive_add -n buddy
> driver=replication,mode=primary,file.driver=nbd,file.host=xx.xx.xx.xx,file.p
> ort=8889,file.export=secondary-disk0,node-name=nbd_client0'}}
> -{ 'execute':'x-blockdev-change', 'arguments':{'parent': 'primary-disk0',
> 'node': 'nbd_client0' } } -{ 'execute': 'migrate-set-capabilities',
> -      'arguments': {'capabilities': [ {'capability': 'x-colo', 'state': true } ] } }
> -{ 'execute': 'migrate', 'arguments': {'uri': 'tcp:xx.xx.xx.xx:8888' } }
> +{'execute': 'human-monitor-command', 'arguments': {'command-line':
> +'drive_add -n buddy
> +driver=replication,mode=primary,file.driver=nbd,file.host=127.0.0.1,fil
> +e.port=9999,file.export=parent0,node-name=replication0'}}
> +{'execute': 'x-blockdev-change', 'arguments':{'parent': 'colo-disk0',
> +'node': 'replication0' } }
> +{'execute': 'migrate-set-capabilities', 'arguments': {'capabilities': [
> +{'capability': 'x-colo', 'state': true } ] } }
> +{'execute': 'migrate', 'arguments': {'uri': 'tcp:127.0.0.1:9998' } }
> 
>    Note:
>    a. There should be only one NBD Client for each primary disk.
> -  b. xx.xx.xx.xx is the secondary physical machine's hostname or IP
> -  c. The qmp command line must be run after running qmp command line in
> +  b. The qmp command line must be run after running qmp command line in
>       secondary qemu.
> 
> -4. After the above steps, you will see, whenever you make changes to PVM,
> SVM will be synced.
> +5. After the above steps, you will see, whenever you make changes to PVM,
> SVM will be synced.
>  You can issue command '{ "execute": "migrate-set-parameters" ,
> "arguments":{ "x-checkpoint-delay": 2000 } }'
> -to change the checkpoint period time
> +to change the idle checkpoint period time
> +
> +6. Failover test
> +You can kill one of the VMs and Failover on the surviving VM:
> +
> +If you killed the Secondary, then follow "Primary Failover". After
> +that, if you want to resume the replication, follow "Primary resume
> replication"
> +
> +If you killed the Primary, then follow "Secondary Failover". After
> +that, if you want to resume the replication, follow "Secondary resume
> replication"
> +
> +== Primary Failover ==
> +The Secondary died, resume on the Primary
> +
> +{'execute': 'x-blockdev-change', 'arguments':{ 'parent': 'colo-disk0',
> +'child': 'children.1'} }
> +{'execute': 'human-monitor-command', 'arguments':{ 'command-line':
> +'drive_del replication0' } }
> +{'execute': 'object-del', 'arguments':{ 'id': 'comp0' } }
> +{'execute': 'object-del', 'arguments':{ 'id': 'iothread1' } }
> +{'execute': 'object-del', 'arguments':{ 'id': 'm0' } }
> +{'execute': 'object-del', 'arguments':{ 'id': 'redire0' } }
> +{'execute': 'object-del', 'arguments':{ 'id': 'redire1' } }
> +{'execute': 'x-colo-lost-heartbeat' }
> +
> +== Secondary Failover ==
> +The Primary died, resume on the Secondary and prepare to become the
> new
> +Primary
> +
> +{'execute': 'nbd-server-stop'}
> +{'execute': 'x-colo-lost-heartbeat'}
> +
> +{'execute': 'object-del', 'arguments':{ 'id': 'f2' } }
> +{'execute': 'object-del', 'arguments':{ 'id': 'f1' } }
> +{'execute': 'chardev-remove', 'arguments':{ 'id': 'red1' } }
> +{'execute': 'chardev-remove', 'arguments':{ 'id': 'red0' } }
> +
> +{'execute': 'chardev-add', 'arguments':{ 'id': 'mirror0', 'backend':
> +{'type': 'socket', 'data': {'addr': { 'type': 'inet', 'data': { 'host':
> +'127.0.0.1', 'port': '9003' } }, 'server': true } } } }
> +{'execute': 'chardev-add', 'arguments':{ 'id': 'compare1', 'backend':
> +{'type': 'socket', 'data': {'addr': { 'type': 'inet', 'data': { 'host':
> +'127.0.0.1', 'port': '9004' } }, 'server': true } } } }
> +{'execute': 'chardev-add', 'arguments':{ 'id': 'compare0', 'backend':
> +{'type': 'socket', 'data': {'addr': { 'type': 'inet', 'data': { 'host':
> +'127.0.0.1', 'port': '9001' } }, 'server': true } } } }
> +{'execute': 'chardev-add', 'arguments':{ 'id': 'compare0-0', 'backend':
> +{'type': 'socket', 'data': {'addr': { 'type': 'inet', 'data': { 'host':
> +'127.0.0.1', 'port': '9001' } }, 'server': false } } } }
> +{'execute': 'chardev-add', 'arguments':{ 'id': 'compare_out',
> +'backend': {'type': 'socket', 'data': {'addr': { 'type': 'inet',
> +'data': { 'host': '127.0.0.1', 'port': '9005' } }, 'server': true } } }
> +}
> +{'execute': 'chardev-add', 'arguments':{ 'id': 'compare_out0',
> +'backend': {'type': 'socket', 'data': {'addr': { 'type': 'inet',
> +'data': { 'host': '127.0.0.1', 'port': '9005' } }, 'server': false } }
> +} }
> +
> +== Primary resume replication ==
> +Resume replication after new Secondary is up.
> +
> +Start the new Secondary (Steps 2 and 3 above), then:

Please note here the "then" is the original secondary node.
It is easy to misunderstand here.

> +{'execute': 'drive-mirror', 'arguments':{ 'device': 'colo-disk0',
> +'job-id': 'resync', 'target': 'nbd://127.0.0.1:9999/parent0', 'mode':
> +'existing', 'format': 'raw', 'sync': 'full'} }
> +

As I mentioned before, the 'nbd://127.0.0.1:9999/parent0' is very confusing, user don't know which node will be connected.

> +Wait until disk is synced, then:
> +{'execute': 'stop'}
> +{'execute': 'block-job-cancel', 'arguments':{ 'device': 'resync'} }
> +
> +{'execute': 'human-monitor-command', 'arguments':{ 'command-line':
> +'drive_add -n buddy
> +driver=replication,mode=primary,file.driver=nbd,file.host=127.0.0.1,fil
> +e.port=9999,file.export=parent0,node-name=replication0'}}
> +{'execute': 'x-blockdev-change', 'arguments':{ 'parent': 'colo-disk0',
> +'node': 'replication0' } }
> +
> +{'execute': 'object-add', 'arguments':{ 'qom-type': 'filter-mirror',
> +'id': 'm0', 'props': { 'netdev': 'hn0', 'queue': 'tx', 'outdev':
> +'mirror0' } } }
> +{'execute': 'object-add', 'arguments':{ 'qom-type':
> +'filter-redirector', 'id': 'redire0', 'props': { 'netdev': 'hn0',
> +'queue': 'rx', 'indev': 'compare_out' } } }
> +{'execute': 'object-add', 'arguments':{ 'qom-type':
> +'filter-redirector', 'id': 'redire1', 'props': { 'netdev': 'hn0',
> +'queue': 'rx', 'outdev': 'compare0' } } }
> +{'execute': 'object-add', 'arguments':{ 'qom-type': 'iothread', 'id':
> +'iothread1' } }
> +{'execute': 'object-add', 'arguments':{ 'qom-type': 'colo-compare',
> +'id': 'comp0', 'props': { 'primary_in': 'compare0-0', 'secondary_in':
> +'compare1', 'outdev': 'compare_out0', 'iothread': 'iothread1' } } }
> +
> +{'execute': 'migrate-set-capabilities', 'arguments':{ 'capabilities': [
> +{'capability': 'x-colo', 'state': true } ] } }
> +{'execute': 'migrate', 'arguments':{ 'uri': 'tcp:127.0.0.1:9998' } }
> +

The guest network have issues here in my test, I can't ping the guest from the host.
Is it works in your test environment?

By the way, after finish this doc we can sync it to Qemu COLO WIKI page.

Thanks
Zhang Chen


> +Note:
> +If this Primary previously was a Secondary, then we need to insert the
> +filters before the filter-rewriter by using the
> +"'insert': 'before', 'position': 'rew0'" Options. See below.
> +
> +== Secondary resume replication ==
> +Become Primary and resume replication after new Secondary is up.
> +
> +Start the new Secondary (Steps 2 and 3 above, but with different image
> +than
> +primary-copy.qcow2 and different VNC port), then:
> +{'execute': 'drive-mirror', 'arguments':{ 'device': 'colo-disk0',
> +'job-id': 'resync', 'target': 'nbd://127.0.0.1:9999/parent0', 'mode':
> +'existing', 'format': 'raw', 'sync': 'full'} }
> +
> +Wait until disk is synced, then:
> +{'execute': 'stop'}
> +{'execute': 'block-job-cancel', 'arguments':{ 'device': 'resync' } }
> 
> -5. Failover test
> -You can kill Primary VM and run 'x_colo_lost_heartbeat' in Secondary VM's -
> monitor at the same time, then SVM will failover and client will not detect
> this -change.
> +{'execute': 'human-monitor-command', 'arguments':{ 'command-line':
> +'drive_add -n buddy
> +driver=replication,mode=primary,file.driver=nbd,file.host=127.0.0.1,fil
> +e.port=9999,file.export=parent0,node-name=replication0'}}
> +{'execute': 'x-blockdev-change', 'arguments':{ 'parent': 'colo-disk0',
> +'node': 'replication0' } }
> 
> -Before issuing '{ "execute": "x-colo-lost-heartbeat" }' command, we have to
> -issue block related command to stop block replication.
> -Primary:
> -  Remove the nbd child from the quorum:
> -  { 'execute': 'x-blockdev-change', 'arguments': {'parent': 'colo-disk0', 'child':
> 'children.1'}}
> -  { 'execute': 'human-monitor-command','arguments': {'command-line':
> 'drive_del blk-buddy0'}}
> -  Note: there is no qmp command to remove the blockdev now
> +{'execute': 'object-add', 'arguments':{ 'qom-type': 'filter-mirror',
> +'id': 'm0', 'props': { 'insert': 'before', 'position': 'id=rew0',
> +'netdev': 'hn0', 'queue': 'tx', 'outdev': 'mirror0' } } }
> +{'execute': 'object-add', 'arguments':{ 'qom-type':
> +'filter-redirector', 'id': 'redire0', 'props': { 'insert': 'before',
> +'position': 'id=rew0', 'netdev': 'hn0', 'queue': 'rx', 'indev':
> +'compare_out' } } }
> +{'execute': 'object-add', 'arguments':{ 'qom-type':
> +'filter-redirector', 'id': 'redire1', 'props': { 'insert': 'before',
> +'position': 'id=rew0', 'netdev': 'hn0', 'queue': 'rx', 'outdev':
> +'compare0' } } }
> +{'execute': 'object-add', 'arguments':{ 'qom-type': 'iothread', 'id':
> +'iothread1' } }
> +{'execute': 'object-add', 'arguments':{ 'qom-type': 'colo-compare',
> +'id': 'comp0', 'props': { 'primary_in': 'compare0-0', 'secondary_in':
> +'compare1', 'outdev': 'compare_out0', 'iothread': 'iothread1' } } }
> 
> -Secondary:
> -  The primary host is down, so we should do the following thing:
> -  { 'execute': 'nbd-server-stop' }
> +{'execute': 'migrate-set-capabilities', 'arguments':{ 'capabilities': [
> +{'capability': 'x-colo', 'state': true } ] } }
> +{'execute': 'migrate', 'arguments':{ 'uri': 'tcp:127.0.0.1:9998' } }
> 
>  == TODO ==
> -1. Support continuous VM replication.
> -2. Support shared storage.
> -3. Develop the heartbeat part.
> -4. Reduce checkpoint VM’s downtime while doing checkpoint.
> +1. Support shared storage.
> +2. Develop the heartbeat part.
> +3. Reduce checkpoint VM’s downtime while doing checkpoint.
> diff --git a/docs/block-replication.txt b/docs/block-replication.txt index
> 6bde6737fb..108e9166a8 100644
> --- a/docs/block-replication.txt
> +++ b/docs/block-replication.txt
> @@ -65,12 +65,12 @@ blocks that are already in QEMU.
>               ^            ||                            .----------
>               |            ||                            | Secondary
>          1 Quorum          ||                            '----------
> -         /      \         ||
> -        /        \        ||
> -   Primary    2 filter
> -     disk         ^                                                             virtio-blk
> -                  |                                                                  ^
> -                3 NBD  ------->  3 NBD                                               |
> +         /      \         ||                                                           virtio-blk
> +        /        \        ||                                                               ^
> +   Primary    2 filter                                                                     |
> +     disk         ^                                                                   7 Quorum
> +                  |                                                                    /
> +                3 NBD  ------->  3 NBD                                                /
>                  client    ||     server                                          2 filter
>                            ||        ^                                                ^
>  --------.                 ||        |                                                |
> @@ -106,6 +106,10 @@ any state that would otherwise be lost by the
> speculative write-through  of the NBD server into the secondary disk. So
> before block replication,  the primary disk and secondary disk should contain
> the same data.
> 
> +7) The secondary also has a quorum node, so after secondary failover it
> +can become the new primary and continue replication.
> +
> +
>  == Failure Handling ==
>  There are 7 internal errors when block replication is running:
>  1. I/O error on primary disk
> @@ -171,16 +175,18 @@ Primary:
>       leading whitespace.
>    5. The qmp command line must be run after running qmp command line in
>       secondary qemu.
> -  6. After failover we need remove children.1 (replication driver).
> +  6. After primary failover we need remove children.1 (replication driver).
> 
>  Secondary:
>    -drive if=none,driver=raw,file.filename=1.raw,id=colo1 \
> -  -drive if=xxx,id=topxxx,driver=replication,mode=secondary,top-
> id=topxxx\
> +  -drive
> + if=none,id=childs1,driver=replication,mode=secondary,top-id=childs1
>           file.file.filename=active_disk.qcow2,\
>           file.driver=qcow2,\
>           file.backing.file.filename=hidden_disk.qcow2,\
>           file.backing.driver=qcow2,\
>           file.backing.backing=colo1
> +  -drive if=xxx,driver=quorum,read-pattern=fifo,id=top-disk1,\
> +         vote-threshold=1,children.0=childs1
> 
>    Then run qmp command in secondary qemu:
>      { 'execute': 'nbd-server-start',
> @@ -234,6 +240,8 @@ Secondary:
>    The primary host is down, so we should do the following thing:
>    { 'execute': 'nbd-server-stop' }
> 
> +Promote Secondary to Primary:
> +  see COLO-FT.txt
> +
>  TODO:
> -1. Continuous block replication
> -2. Shared disk
> +1. Shared disk
> --
> 2.20.1

RE: [PATCH v5 2/4] tests/test-replication.c: Add test for ignoring requests after failover

[Zhang, Chen]

> -----Original Message-----
> From: Lukas Straub <lukasstraub2@web.de>
> Sent: Monday, September 16, 2019 3:20 AM
> To: qemu-devel <qemu-devel@nongnu.org>
> Cc: Zhang, Chen <chen.zhang@intel.com>; Jason Wang
> <jasowang@redhat.com>; Wen Congyang <wencongyang2@huawei.com>;
> Xie Changlong <xiechanglong.d@gmail.com>; kwolf@redhat.com;
> mreitz@redhat.com
> Subject: [PATCH v5 2/4] tests/test-replication.c: Add test for ignoring
> requests after failover
> 
> This simulates the case that happens when we resume COLO after failover.
> 

It looks change the title to "Add test for secondary node continuous backup" is better.

> Signed-off-by: Lukas Straub <lukasstraub2@web.de>
> ---
>  tests/test-replication.c | 52
> ++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 52 insertions(+)
> 
> diff --git a/tests/test-replication.c b/tests/test-replication.c index
> f085d1993a..5addfc2227 100644
> --- a/tests/test-replication.c
> +++ b/tests/test-replication.c
> @@ -489,6 +489,56 @@ static void test_secondary_stop(void)
>      teardown_secondary();
>  }
> 
> +static void test_secondary_failover_then_ignore_requests(void)

Same as title, I think change to "test_secondary_continuous_backup" is more clear.

Thanks
Zhang Chen

> +{
> +    BlockBackend *top_blk, *local_blk;
> +    Error *local_err = NULL;
> +
> +    top_blk = start_secondary();
> +    replication_start_all(REPLICATION_MODE_SECONDARY, &local_err);
> +    g_assert(!local_err);
> +
> +    /* write 0x22 to s_local_disk (IMG_SIZE / 2, IMG_SIZE) */
> +    local_blk = blk_by_name(S_LOCAL_DISK_ID);
> +    test_blk_write(local_blk, 0x22, IMG_SIZE / 2, IMG_SIZE / 2, false);
> +
> +    /* replication will backup s_local_disk to s_hidden_disk */
> +    test_blk_read(top_blk, 0x11, IMG_SIZE / 2,
> +                  IMG_SIZE / 2, 0, IMG_SIZE, false);
> +
> +    /* write 0x33 to s_active_disk (0, IMG_SIZE / 2) */
> +    test_blk_write(top_blk, 0x33, 0, IMG_SIZE / 2, false);
> +
> +    /* do failover (active commit) */
> +    replication_stop_all(true, &local_err);
> +    g_assert(!local_err);
> +
> +    /* it should ignore all requests from now on */
> +
> +    /* start after failover */
> +    replication_start_all(REPLICATION_MODE_PRIMARY, &local_err);
> +    g_assert(!local_err);
> +
> +    /* checkpoint */
> +    replication_do_checkpoint_all(&local_err);
> +    g_assert(!local_err);
> +
> +    /* stop */
> +    replication_stop_all(true, &local_err);
> +    g_assert(!local_err);
> +
> +    /* read from s_local_disk (0, IMG_SIZE / 2) */
> +    test_blk_read(top_blk, 0x33, 0, IMG_SIZE / 2,
> +                  0, IMG_SIZE / 2, false);
> +
> +
> +    /* read from s_local_disk (IMG_SIZE / 2, IMG_SIZE) */
> +    test_blk_read(top_blk, 0x22, IMG_SIZE / 2,
> +                  IMG_SIZE / 2, 0, IMG_SIZE, false);
> +
> +    teardown_secondary();
> +}
> +
>  static void test_secondary_do_checkpoint(void)
>  {
>      BlockBackend *top_blk, *local_blk;
> @@ -584,6 +634,8 @@ int main(int argc, char **argv)
>      g_test_add_func("/replication/secondary/write", test_secondary_write);
>      g_test_add_func("/replication/secondary/start", test_secondary_start);
>      g_test_add_func("/replication/secondary/stop",  test_secondary_stop);
> +
> g_test_add_func("/replication/secondary/failover_then_ignore_requests",
> +                    test_secondary_failover_then_ignore_requests);
>      g_test_add_func("/replication/secondary/do_checkpoint",
>                      test_secondary_do_checkpoint);
>      g_test_add_func("/replication/secondary/get_error_all",
> --
> 2.20.1

Re: [PATCH v5 3/4] net/filter.c: Add Options to insert filters anywhere in the filter list

[Lukas Straub]

On Thu, 26 Sep 2019 17:02:58 +0000
"Zhang, Chen" <chen.zhang@intel.com> wrote:
> > diff --git a/qemu-options.hx b/qemu-options.hx index
> > 08749a3391..23fa5a344e 100644
> > --- a/qemu-options.hx
> > +++ b/qemu-options.hx
> > @@ -4368,7 +4368,7 @@ applications, they can do this through this
> > parameter. Its format is  a gnutls priority string as described at
> > @url{https://gnutls.org/manual/html_node/Priority-Strings.html}.
> >
> > -@item -object filter-
> > buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@var{
> > all|rx|tx}][,status=@var{on|off}]
> > +@item -object
> > +filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue
> > +=@var{all|rx|tx}][,status=@var{on|off}][,position=@var{head|tail|id=<id
> > +>}][,insert=@var{behind|before}]
> >
> >  Interval @var{t} can't be 0, this filter batches the packet delivery: all  packets
> > arriving in a given interval on netdev @var{netdevid} are delayed @@ -
> > 4387,11 +4387,11 @@ queue @var{all|rx|tx} is an option that can be applied
> > to any netfilter.
> >  @option{tx}: the filter is attached to the transmit queue of the netdev,
> >               where it will receive packets sent by the netdev.
> >
> > -@item -object filter-
> > mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queue
> > =@var{all|rx|tx}[,vnet_hdr_support]
> > +@item -object
> > +filter-mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},
> > +queue=@var{all|rx|tx}[,vnet_hdr_support][,position=@var{head|tail|id=<
> > i
> > +d>}][,insert=@var{behind|before}]
> >
> >  filter-mirror on netdev @var{netdevid},mirror net packet to
> > chardev@var{chardevid}, if it has the vnet_hdr_support flag, filter-mirror will
> > mirror packet with vnet_hdr_len.
> >
>
> Please add description for the newly added parameter in each filter.
> After that:
> Reviewed-by: Zhang Chen <chen.zhang@intel.com>
>
> Thanks
> Zhang Chen

Hi,
I will add a single description like its currently done with the "queue" option, noting that
it applies to any netfilter. Is that Ok?

Regards,
Lukas Straub

>
> > -@item -object filter-
> > redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},out
> > dev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support]
> > +@item -object
> > +filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevi
> > +d},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support][,p
> > os
> > +ition=@var{head|tail|id=<id>}][,insert=@var{behind|before}]
> >
> >  filter-redirector on netdev @var{netdevid},redirect filter's net packet to
> > chardev  @var{chardevid},and redirect indev's packet to filter.if it has the
> > vnet_hdr_support flag, @@ -4400,7 +4400,7 @@ Create a filter-redirector
> > we need to differ outdev id from indev id, id can not  be the same. we can
> > just use indev or outdev, but at least one of indev or outdev  need to be
> > specified.
> >
> > -@item -object filter-
> > rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vnet_
> > hdr_support]
> > +@item -object
> > +filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx}
> > +,[vnet_hdr_support][,position=@var{head|tail|id=<id>}][,insert=@var{beh
> > +ind|before}]
> >
> >  Filter-rewriter is a part of COLO project.It will rewrite tcp packet to
> > secondary from primary to keep secondary tcp connection,and rewrite @@ -
> > 4413,7 +4413,7 @@ colo secondary:
> >  -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
> >  -object filter-rewriter,id=rew0,netdev=hn0,queue=all
> >
> > -@item -object filter-
> > dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var{
> > len}]
> > +@item -object
> > +filter-
> > dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=
> > +@var{len}][,position=@var{head|tail|id=<id>}][,insert=@var{behind|befor
> > +e}]
> >
> >  Dump the network traffic on netdev @var{dev} to the file specified by
> > @var{filename}. At most @var{len} bytes (64k by default) per packet are
> > stored.
> > --
> > 2.20.1
>

Re: [PATCH v5 2/4] tests/test-replication.c: Add test for ignoring requests after failover

[Lukas Straub]

On Thu, 26 Sep 2019 17:40:03 +0000
"Zhang, Chen" <chen.zhang@intel.com> wrote:

> > -----Original Message-----
> > From: Lukas Straub <lukasstraub2@web.de>
> > Sent: Monday, September 16, 2019 3:20 AM
> > To: qemu-devel <qemu-devel@nongnu.org>
> > Cc: Zhang, Chen <chen.zhang@intel.com>; Jason Wang
> > <jasowang@redhat.com>; Wen Congyang <wencongyang2@huawei.com>;
> > Xie Changlong <xiechanglong.d@gmail.com>; kwolf@redhat.com;
> > mreitz@redhat.com
> > Subject: [PATCH v5 2/4] tests/test-replication.c: Add test for ignoring
> > requests after failover
> >
> > This simulates the case that happens when we resume COLO after failover.
> >
>
> It looks change the title to "Add test for secondary node continuous backup" is better.

Did you mean "continuous replication"? Would "Add test for secondary node continuing replication" be Ok?

> > Signed-off-by: Lukas Straub <lukasstraub2@web.de>
> > ---
> >  tests/test-replication.c | 52
> > ++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 52 insertions(+)
> >
> > diff --git a/tests/test-replication.c b/tests/test-replication.c index
> > f085d1993a..5addfc2227 100644
> > --- a/tests/test-replication.c
> > +++ b/tests/test-replication.c
> > @@ -489,6 +489,56 @@ static void test_secondary_stop(void)
> >      teardown_secondary();
> >  }
> >
> > +static void test_secondary_failover_then_ignore_requests(void)
>
> Same as title, I think change to "test_secondary_continuous_backup" is more clear.
>
> Thanks
> Zhang Chen
>
> > +{
> > +    BlockBackend *top_blk, *local_blk;
> > +    Error *local_err = NULL;
> > +
> > +    top_blk = start_secondary();
> > +    replication_start_all(REPLICATION_MODE_SECONDARY, &local_err);
> > +    g_assert(!local_err);
> > +
> > +    /* write 0x22 to s_local_disk (IMG_SIZE / 2, IMG_SIZE) */
> > +    local_blk = blk_by_name(S_LOCAL_DISK_ID);
> > +    test_blk_write(local_blk, 0x22, IMG_SIZE / 2, IMG_SIZE / 2, false);
> > +
> > +    /* replication will backup s_local_disk to s_hidden_disk */
> > +    test_blk_read(top_blk, 0x11, IMG_SIZE / 2,
> > +                  IMG_SIZE / 2, 0, IMG_SIZE, false);
> > +
> > +    /* write 0x33 to s_active_disk (0, IMG_SIZE / 2) */
> > +    test_blk_write(top_blk, 0x33, 0, IMG_SIZE / 2, false);
> > +
> > +    /* do failover (active commit) */
> > +    replication_stop_all(true, &local_err);
> > +    g_assert(!local_err);
> > +
> > +    /* it should ignore all requests from now on */
> > +
> > +    /* start after failover */
> > +    replication_start_all(REPLICATION_MODE_PRIMARY, &local_err);
> > +    g_assert(!local_err);
> > +
> > +    /* checkpoint */
> > +    replication_do_checkpoint_all(&local_err);
> > +    g_assert(!local_err);
> > +
> > +    /* stop */
> > +    replication_stop_all(true, &local_err);
> > +    g_assert(!local_err);
> > +
> > +    /* read from s_local_disk (0, IMG_SIZE / 2) */
> > +    test_blk_read(top_blk, 0x33, 0, IMG_SIZE / 2,
> > +                  0, IMG_SIZE / 2, false);
> > +
> > +
> > +    /* read from s_local_disk (IMG_SIZE / 2, IMG_SIZE) */
> > +    test_blk_read(top_blk, 0x22, IMG_SIZE / 2,
> > +                  IMG_SIZE / 2, 0, IMG_SIZE, false);
> > +
> > +    teardown_secondary();
> > +}
> > +
> >  static void test_secondary_do_checkpoint(void)
> >  {
> >      BlockBackend *top_blk, *local_blk;
> > @@ -584,6 +634,8 @@ int main(int argc, char **argv)
> >      g_test_add_func("/replication/secondary/write", test_secondary_write);
> >      g_test_add_func("/replication/secondary/start", test_secondary_start);
> >      g_test_add_func("/replication/secondary/stop",  test_secondary_stop);
> > +
> > g_test_add_func("/replication/secondary/failover_then_ignore_requests",
> > +                    test_secondary_failover_then_ignore_requests);
> >      g_test_add_func("/replication/secondary/do_checkpoint",
> >                      test_secondary_do_checkpoint);
> >      g_test_add_func("/replication/secondary/get_error_all",
> > --
> > 2.20.1
>

Re: [PATCH v5 4/4] colo: Update Documentation for continuous replication

[Lukas Straub]

On Thu, 26 Sep 2019 17:27:35 +0000
"Zhang, Chen" <chen.zhang@intel.com> wrote:

> > -----Original Message-----
> > From: Lukas Straub <lukasstraub2@web.de>
> > Sent: Monday, September 16, 2019 3:20 AM
> > To: qemu-devel <qemu-devel@nongnu.org>
> > Cc: Zhang, Chen <chen.zhang@intel.com>; Jason Wang
> > <jasowang@redhat.com>; Wen Congyang <wencongyang2@huawei.com>;
> > Xie Changlong <xiechanglong.d@gmail.com>; kwolf@redhat.com;
> > mreitz@redhat.com
> > Subject: [PATCH v5 4/4] colo: Update Documentation for continuous
> > replication
> > 
> > Document the qemu command-line and qmp commands for continuous
> > replication
> > 
> > Signed-off-by: Lukas Straub <lukasstraub2@web.de>
> > ---
> >  docs/COLO-FT.txt           | 212 +++++++++++++++++++++++++++----------
> >  docs/block-replication.txt |  28 +++--
> >  2 files changed, 173 insertions(+), 67 deletions(-)
> > 
> > diff --git a/docs/COLO-FT.txt b/docs/COLO-FT.txt index
> > ad24680d13..e98c95ca2b 100644
> > --- a/docs/COLO-FT.txt
> > +++ b/docs/COLO-FT.txt
> > @@ -145,35 +145,65 @@ The diagram just shows the main qmp command,
> > you can get the detail  in test procedure.
> > 
> >  == Test procedure ==
> > -1. Startup qemu
> > -Primary:
> > -# qemu-system-x86_64 -accel kvm -m 2048 -smp 2 -qmp stdio -name
> > primary \
> > -  -device piix3-usb-uhci -vnc :7 \
> > -  -device usb-tablet -netdev tap,id=hn0,vhost=off \
> > -  -device virtio-net-pci,id=net-pci0,netdev=hn0 \
> > -  -drive if=virtio,id=primary-disk0,driver=quorum,read-pattern=fifo,vote-
> > threshold=1,\
> > -         children.0.file.filename=1.raw,\
> > -         children.0.driver=raw -S
> > -Secondary:
> > -# qemu-system-x86_64 -accel kvm -m 2048 -smp 2 -qmp stdio -name
> > secondary \
> > -  -device piix3-usb-uhci -vnc :7 \
> > -  -device usb-tablet -netdev tap,id=hn0,vhost=off \
> > -  -device virtio-net-pci,id=net-pci0,netdev=hn0 \
> > -  -drive if=none,id=secondary-disk0,file.filename=1.raw,driver=raw,node-
> > name=node0 \
> > -  -drive if=virtio,id=active-disk0,driver=replication,mode=secondary,\
> > -         file.driver=qcow2,top-id=active-disk0,\
> > -         file.file.filename=/mnt/ramfs/active_disk.img,\
> > -         file.backing.driver=qcow2,\
> > -         file.backing.file.filename=/mnt/ramfs/hidden_disk.img,\
> > -         file.backing.backing=secondary-disk0 \
> > -  -incoming tcp:0:8888
> > -
> > -2. On Secondary VM's QEMU monitor, issue command
> > +Note: Here we are running both instances on the same Machine for
> > +testing, change the IP Addresses if you want to run it on two Hosts
> > +
> > +== Startup qemu ==
> > +1. Primary:
> > +# imagefolder="/mnt/vms/colo-test"
> > +
> > +The disks for the primary and secondary need to be the same before
> > +starting colo # cp --reflink=auto $imagefolder/primary.qcow2
> > +$imagefolder/primary-copy.qcow2
> > +
> > +# qemu-system-x86_64 -enable-kvm -cpu qemu64,+kvmclock -m 512 -smp
> > 1 -qmp stdio \
> > +   -vnc :0 -device piix3-usb-uhci -device usb-tablet -name primary \
> > +   -netdev tap,id=hn0,vhost=off,helper=/usr/lib/qemu/qemu-bridge-helper
> > \
> > +   -device rtl8139,id=e0,netdev=hn0 \
> > +   -chardev socket,id=mirror0,host=127.0.0.1,port=9003,server,nowait \
> > +   -chardev socket,id=compare1,host=127.0.0.1,port=9004,server,wait \
> > +   -chardev socket,id=compare0,host=127.0.0.1,port=9001,server,nowait \
> > +   -chardev socket,id=compare0-0,host=127.0.0.1,port=9001 \
> > +   -chardev socket,id=compare_out,host=127.0.0.1,port=9005,server,nowait
> > \
> > +   -chardev socket,id=compare_out0,host=127.0.0.1,port=9005 \
> > +   -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 \
> > +   -object filter-
> > redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out \
> > +   -object filter-
> > redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 \
> > +   -object iothread,id=iothread1 \
> > +   -object
> > +colo-compare,id=comp0,primary_in=compare0-
> > 0,secondary_in=compare1,\
> > +outdev=compare_out0,iothread=iothread1 \
> > +   -drive
> > +if=ide,id=colo-disk0,driver=quorum,read-pattern=fifo,vote-threshold=1,\
> > +children.0.file.filename=$imagefolder/primary.qcow2,children.0.driver=q
> > +cow2 -S
> > +
> > +2. Secondary:
> > +# imagefolder="/mnt/vms/colo-test"
> > +
> > +# qemu-img create -f qcow2 $imagefolder/secondary-active.qcow2 10G
> > +
> > +# qemu-img create -f qcow2 $imagefolder/secondary-hidden.qcow2 10G
> > +
> > +# qemu-system-x86_64 -enable-kvm -cpu qemu64,+kvmclock -m 512 -smp
> > 1 -qmp stdio \
> > +   -vnc :1 -device piix3-usb-uhci -device usb-tablet -name secondary \
> > +   -netdev tap,id=hn0,vhost=off,helper=/usr/lib/qemu/qemu-bridge-helper
> > \
> > +   -device rtl8139,id=e0,netdev=hn0 \
> > +   -chardev socket,id=red0,host=127.0.0.1,port=9003,reconnect=1 \
> > +   -chardev socket,id=red1,host=127.0.0.1,port=9004,reconnect=1 \
> > +   -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 \
> > +   -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 \
> > +   -object filter-rewriter,id=rew0,netdev=hn0,queue=all \
> > +   -drive if=none,id=parent0,file.filename=$imagefolder/primary-
> > copy.qcow2,driver=qcow2 \
> > +   -drive
> > +if=none,id=childs0,driver=replication,mode=secondary,file.driver=qcow2,
> > +\
> > +top-id=childs0,file.file.filename=$imagefolder/secondary-active.qcow2,\
> > +file.backing.driver=qcow2,file.backing.file.filename=$imagefolder/secon
> > +dary-hidden.qcow2,\
> > +file.backing.backing=parent0 \
> > +   -drive
> > +if=ide,id=colo-disk0,driver=quorum,read-pattern=fifo,vote-threshold=1,\
> > +children.0=childs0 \
> > +   -incoming tcp:0:9998
> > +  
> 
> I know in your COLO test environment, all the node running in same physical machine,
> but current COLO start parameter demo easy to misunderstand users.
> I think we can introduce primary node as 192.168.1.1, secondary node as 192.168.1.2.
> Same issue for the VM image, we should avoid the "primary-copy.qow2". 
> Make two node independent is more clear. 
> 

Ok, I will remove the primary-copy stuff. But I have a better idea for the IP addresses:
Using 127.0.0.1 for Primary and 127.0.0.2 for Secondary. Both point to localhost, making
quick testing by simple copy-paste possible when using different values for the imagefolder
Variable. At the same time Users see which IP to substitute for the remote node when using 
multiple Hosts and we avoid the confusion with primary-copy.
What do you think?

> 
> > +
> > +3. On Secondary VM's QEMU monitor, issue command
> >  {'execute':'qmp_capabilities'}
> > -{ 'execute': 'nbd-server-start',
> > -  'arguments': {'addr': {'type': 'inet', 'data': {'host': 'xx.xx.xx.xx', 'port':
> > '8889'} } } -}
> > -{'execute': 'nbd-server-add', 'arguments': {'device': 'secondary-disk0',
> > 'writable': true } }
> > +{'execute': 'nbd-server-start', 'arguments': {'addr': {'type': 'inet',
> > +'data': {'host': '127.0.0.1', 'port': '9999'} } } }
> > +{'execute': 'nbd-server-add', 'arguments': {'device': 'parent0',
> > +'writable': true } }
> > 
> >  Note:
> >    a. The qmp command nbd-server-start and nbd-server-add must be run
> > @@ -182,44 +212,112 @@ Note:
> >       same.
> >    c. It is better to put active disk and hidden disk in ramdisk.
> > 
> > -3. On Primary VM's QEMU monitor, issue command:
> > +4. On Primary VM's QEMU monitor, issue command:
> >  {'execute':'qmp_capabilities'}
> > -{ 'execute': 'human-monitor-command',
> > -  'arguments': {'command-line': 'drive_add -n buddy
> > driver=replication,mode=primary,file.driver=nbd,file.host=xx.xx.xx.xx,file.p
> > ort=8889,file.export=secondary-disk0,node-name=nbd_client0'}}
> > -{ 'execute':'x-blockdev-change', 'arguments':{'parent': 'primary-disk0',
> > 'node': 'nbd_client0' } } -{ 'execute': 'migrate-set-capabilities',
> > -      'arguments': {'capabilities': [ {'capability': 'x-colo', 'state': true } ] } }
> > -{ 'execute': 'migrate', 'arguments': {'uri': 'tcp:xx.xx.xx.xx:8888' } }
> > +{'execute': 'human-monitor-command', 'arguments': {'command-line':
> > +'drive_add -n buddy
> > +driver=replication,mode=primary,file.driver=nbd,file.host=127.0.0.1,fil
> > +e.port=9999,file.export=parent0,node-name=replication0'}}
> > +{'execute': 'x-blockdev-change', 'arguments':{'parent': 'colo-disk0',
> > +'node': 'replication0' } }
> > +{'execute': 'migrate-set-capabilities', 'arguments': {'capabilities': [
> > +{'capability': 'x-colo', 'state': true } ] } }
> > +{'execute': 'migrate', 'arguments': {'uri': 'tcp:127.0.0.1:9998' } }
> > 
> >    Note:
> >    a. There should be only one NBD Client for each primary disk.
> > -  b. xx.xx.xx.xx is the secondary physical machine's hostname or IP
> > -  c. The qmp command line must be run after running qmp command line in
> > +  b. The qmp command line must be run after running qmp command line in
> >       secondary qemu.
> > 
> > -4. After the above steps, you will see, whenever you make changes to PVM,
> > SVM will be synced.
> > +5. After the above steps, you will see, whenever you make changes to PVM,
> > SVM will be synced.
> >  You can issue command '{ "execute": "migrate-set-parameters" ,
> > "arguments":{ "x-checkpoint-delay": 2000 } }'
> > -to change the checkpoint period time
> > +to change the idle checkpoint period time
> > +
> > +6. Failover test
> > +You can kill one of the VMs and Failover on the surviving VM:
> > +
> > +If you killed the Secondary, then follow "Primary Failover". After
> > +that, if you want to resume the replication, follow "Primary resume
> > replication"
> > +
> > +If you killed the Primary, then follow "Secondary Failover". After
> > +that, if you want to resume the replication, follow "Secondary resume
> > replication"
> > +
> > +== Primary Failover ==
> > +The Secondary died, resume on the Primary
> > +
> > +{'execute': 'x-blockdev-change', 'arguments':{ 'parent': 'colo-disk0',
> > +'child': 'children.1'} }
> > +{'execute': 'human-monitor-command', 'arguments':{ 'command-line':
> > +'drive_del replication0' } }
> > +{'execute': 'object-del', 'arguments':{ 'id': 'comp0' } }
> > +{'execute': 'object-del', 'arguments':{ 'id': 'iothread1' } }
> > +{'execute': 'object-del', 'arguments':{ 'id': 'm0' } }
> > +{'execute': 'object-del', 'arguments':{ 'id': 'redire0' } }
> > +{'execute': 'object-del', 'arguments':{ 'id': 'redire1' } }
> > +{'execute': 'x-colo-lost-heartbeat' }
> > +
> > +== Secondary Failover ==
> > +The Primary died, resume on the Secondary and prepare to become the
> > new
> > +Primary
> > +
> > +{'execute': 'nbd-server-stop'}
> > +{'execute': 'x-colo-lost-heartbeat'}
> > +
> > +{'execute': 'object-del', 'arguments':{ 'id': 'f2' } }
> > +{'execute': 'object-del', 'arguments':{ 'id': 'f1' } }
> > +{'execute': 'chardev-remove', 'arguments':{ 'id': 'red1' } }
> > +{'execute': 'chardev-remove', 'arguments':{ 'id': 'red0' } }
> > +
> > +{'execute': 'chardev-add', 'arguments':{ 'id': 'mirror0', 'backend':
> > +{'type': 'socket', 'data': {'addr': { 'type': 'inet', 'data': { 'host':
> > +'127.0.0.1', 'port': '9003' } }, 'server': true } } } }
> > +{'execute': 'chardev-add', 'arguments':{ 'id': 'compare1', 'backend':
> > +{'type': 'socket', 'data': {'addr': { 'type': 'inet', 'data': { 'host':
> > +'127.0.0.1', 'port': '9004' } }, 'server': true } } } }
> > +{'execute': 'chardev-add', 'arguments':{ 'id': 'compare0', 'backend':
> > +{'type': 'socket', 'data': {'addr': { 'type': 'inet', 'data': { 'host':
> > +'127.0.0.1', 'port': '9001' } }, 'server': true } } } }
> > +{'execute': 'chardev-add', 'arguments':{ 'id': 'compare0-0', 'backend':
> > +{'type': 'socket', 'data': {'addr': { 'type': 'inet', 'data': { 'host':
> > +'127.0.0.1', 'port': '9001' } }, 'server': false } } } }
> > +{'execute': 'chardev-add', 'arguments':{ 'id': 'compare_out',
> > +'backend': {'type': 'socket', 'data': {'addr': { 'type': 'inet',
> > +'data': { 'host': '127.0.0.1', 'port': '9005' } }, 'server': true } } }
> > +}
> > +{'execute': 'chardev-add', 'arguments':{ 'id': 'compare_out0',
> > +'backend': {'type': 'socket', 'data': {'addr': { 'type': 'inet',
> > +'data': { 'host': '127.0.0.1', 'port': '9005' } }, 'server': false } }
> > +} }
> > +
> > +== Primary resume replication ==
> > +Resume replication after new Secondary is up.
> > +
> > +Start the new Secondary (Steps 2 and 3 above), then:  
> 
> Please note here the "then" is the original secondary node.
> It is easy to misunderstand here.

Ok, I will make this more clear.

> > +{'execute': 'drive-mirror', 'arguments':{ 'device': 'colo-disk0',
> > +'job-id': 'resync', 'target': 'nbd://127.0.0.1:9999/parent0', 'mode':
> > +'existing', 'format': 'raw', 'sync': 'full'} }
> > +  
> 
> As I mentioned before, the 'nbd://127.0.0.1:9999/parent0' is very confusing, user don't know which node will be connected.
> 
> > +Wait until disk is synced, then:
> > +{'execute': 'stop'}
> > +{'execute': 'block-job-cancel', 'arguments':{ 'device': 'resync'} }
> > +
> > +{'execute': 'human-monitor-command', 'arguments':{ 'command-line':
> > +'drive_add -n buddy
> > +driver=replication,mode=primary,file.driver=nbd,file.host=127.0.0.1,fil
> > +e.port=9999,file.export=parent0,node-name=replication0'}}
> > +{'execute': 'x-blockdev-change', 'arguments':{ 'parent': 'colo-disk0',
> > +'node': 'replication0' } }
> > +
> > +{'execute': 'object-add', 'arguments':{ 'qom-type': 'filter-mirror',
> > +'id': 'm0', 'props': { 'netdev': 'hn0', 'queue': 'tx', 'outdev':
> > +'mirror0' } } }
> > +{'execute': 'object-add', 'arguments':{ 'qom-type':
> > +'filter-redirector', 'id': 'redire0', 'props': { 'netdev': 'hn0',
> > +'queue': 'rx', 'indev': 'compare_out' } } }
> > +{'execute': 'object-add', 'arguments':{ 'qom-type':
> > +'filter-redirector', 'id': 'redire1', 'props': { 'netdev': 'hn0',
> > +'queue': 'rx', 'outdev': 'compare0' } } }
> > +{'execute': 'object-add', 'arguments':{ 'qom-type': 'iothread', 'id':
> > +'iothread1' } }
> > +{'execute': 'object-add', 'arguments':{ 'qom-type': 'colo-compare',
> > +'id': 'comp0', 'props': { 'primary_in': 'compare0-0', 'secondary_in':
> > +'compare1', 'outdev': 'compare_out0', 'iothread': 'iothread1' } } }
> > +
> > +{'execute': 'migrate-set-capabilities', 'arguments':{ 'capabilities': [
> > +{'capability': 'x-colo', 'state': true } ] } }
> > +{'execute': 'migrate', 'arguments':{ 'uri': 'tcp:127.0.0.1:9998' } }
> > +  
> 
> The guest network have issues here in my test, I can't ping the guest from the host.
> Is it works in your test environment?

Yes, it works for me (based on v4.1.0). I simply copy-paste everything here 1:1
for testing.

Regards,
Lukas Straub

> By the way, after finish this doc we can sync it to Qemu COLO WIKI page.
> 
> Thanks
> Zhang Chen
> 
> 
> > +Note:
> > +If this Primary previously was a Secondary, then we need to insert the
> > +filters before the filter-rewriter by using the
> > +"'insert': 'before', 'position': 'rew0'" Options. See below.
> > +
> > +== Secondary resume replication ==
> > +Become Primary and resume replication after new Secondary is up.
> > +
> > +Start the new Secondary (Steps 2 and 3 above, but with different image
> > +than
> > +primary-copy.qcow2 and different VNC port), then:
> > +{'execute': 'drive-mirror', 'arguments':{ 'device': 'colo-disk0',
> > +'job-id': 'resync', 'target': 'nbd://127.0.0.1:9999/parent0', 'mode':
> > +'existing', 'format': 'raw', 'sync': 'full'} }
> > +
> > +Wait until disk is synced, then:
> > +{'execute': 'stop'}
> > +{'execute': 'block-job-cancel', 'arguments':{ 'device': 'resync' } }
> > 
> > -5. Failover test
> > -You can kill Primary VM and run 'x_colo_lost_heartbeat' in Secondary VM's -
> > monitor at the same time, then SVM will failover and client will not detect
> > this -change.
> > +{'execute': 'human-monitor-command', 'arguments':{ 'command-line':
> > +'drive_add -n buddy
> > +driver=replication,mode=primary,file.driver=nbd,file.host=127.0.0.1,fil
> > +e.port=9999,file.export=parent0,node-name=replication0'}}
> > +{'execute': 'x-blockdev-change', 'arguments':{ 'parent': 'colo-disk0',
> > +'node': 'replication0' } }
> > 
> > -Before issuing '{ "execute": "x-colo-lost-heartbeat" }' command, we have to
> > -issue block related command to stop block replication.
> > -Primary:
> > -  Remove the nbd child from the quorum:
> > -  { 'execute': 'x-blockdev-change', 'arguments': {'parent': 'colo-disk0', 'child':
> > 'children.1'}}
> > -  { 'execute': 'human-monitor-command','arguments': {'command-line':
> > 'drive_del blk-buddy0'}}
> > -  Note: there is no qmp command to remove the blockdev now
> > +{'execute': 'object-add', 'arguments':{ 'qom-type': 'filter-mirror',
> > +'id': 'm0', 'props': { 'insert': 'before', 'position': 'id=rew0',
> > +'netdev': 'hn0', 'queue': 'tx', 'outdev': 'mirror0' } } }
> > +{'execute': 'object-add', 'arguments':{ 'qom-type':
> > +'filter-redirector', 'id': 'redire0', 'props': { 'insert': 'before',
> > +'position': 'id=rew0', 'netdev': 'hn0', 'queue': 'rx', 'indev':
> > +'compare_out' } } }
> > +{'execute': 'object-add', 'arguments':{ 'qom-type':
> > +'filter-redirector', 'id': 'redire1', 'props': { 'insert': 'before',
> > +'position': 'id=rew0', 'netdev': 'hn0', 'queue': 'rx', 'outdev':
> > +'compare0' } } }
> > +{'execute': 'object-add', 'arguments':{ 'qom-type': 'iothread', 'id':
> > +'iothread1' } }
> > +{'execute': 'object-add', 'arguments':{ 'qom-type': 'colo-compare',
> > +'id': 'comp0', 'props': { 'primary_in': 'compare0-0', 'secondary_in':
> > +'compare1', 'outdev': 'compare_out0', 'iothread': 'iothread1' } } }
> > 
> > -Secondary:
> > -  The primary host is down, so we should do the following thing:
> > -  { 'execute': 'nbd-server-stop' }
> > +{'execute': 'migrate-set-capabilities', 'arguments':{ 'capabilities': [
> > +{'capability': 'x-colo', 'state': true } ] } }
> > +{'execute': 'migrate', 'arguments':{ 'uri': 'tcp:127.0.0.1:9998' } }
> > 
> >  == TODO ==
> > -1. Support continuous VM replication.
> > -2. Support shared storage.
> > -3. Develop the heartbeat part.
> > -4. Reduce checkpoint VM’s downtime while doing checkpoint.
> > +1. Support shared storage.
> > +2. Develop the heartbeat part.
> > +3. Reduce checkpoint VM’s downtime while doing checkpoint.
> > diff --git a/docs/block-replication.txt b/docs/block-replication.txt index
> > 6bde6737fb..108e9166a8 100644
> > --- a/docs/block-replication.txt
> > +++ b/docs/block-replication.txt
> > @@ -65,12 +65,12 @@ blocks that are already in QEMU.
> >               ^            ||                            .----------
> >               |            ||                            | Secondary
> >          1 Quorum          ||                            '----------
> > -         /      \         ||
> > -        /        \        ||
> > -   Primary    2 filter
> > -     disk         ^                                                             virtio-blk
> > -                  |                                                                  ^
> > -                3 NBD  ------->  3 NBD                                               |
> > +         /      \         ||                                                           virtio-blk
> > +        /        \        ||                                                               ^
> > +   Primary    2 filter                                                                     |
> > +     disk         ^                                                                   7 Quorum
> > +                  |                                                                    /
> > +                3 NBD  ------->  3 NBD                                                /
> >                  client    ||     server                                          2 filter
> >                            ||        ^                                                ^
> >  --------.                 ||        |                                                |
> > @@ -106,6 +106,10 @@ any state that would otherwise be lost by the
> > speculative write-through  of the NBD server into the secondary disk. So
> > before block replication,  the primary disk and secondary disk should contain
> > the same data.
> > 
> > +7) The secondary also has a quorum node, so after secondary failover it
> > +can become the new primary and continue replication.
> > +
> > +
> >  == Failure Handling ==
> >  There are 7 internal errors when block replication is running:
> >  1. I/O error on primary disk
> > @@ -171,16 +175,18 @@ Primary:
> >       leading whitespace.
> >    5. The qmp command line must be run after running qmp command line in
> >       secondary qemu.
> > -  6. After failover we need remove children.1 (replication driver).
> > +  6. After primary failover we need remove children.1 (replication driver).
> > 
> >  Secondary:
> >    -drive if=none,driver=raw,file.filename=1.raw,id=colo1 \
> > -  -drive if=xxx,id=topxxx,driver=replication,mode=secondary,top-
> > id=topxxx\
> > +  -drive
> > + if=none,id=childs1,driver=replication,mode=secondary,top-id=childs1
> >           file.file.filename=active_disk.qcow2,\
> >           file.driver=qcow2,\
> >           file.backing.file.filename=hidden_disk.qcow2,\
> >           file.backing.driver=qcow2,\
> >           file.backing.backing=colo1
> > +  -drive if=xxx,driver=quorum,read-pattern=fifo,id=top-disk1,\
> > +         vote-threshold=1,children.0=childs1
> > 
> >    Then run qmp command in secondary qemu:
> >      { 'execute': 'nbd-server-start',
> > @@ -234,6 +240,8 @@ Secondary:
> >    The primary host is down, so we should do the following thing:
> >    { 'execute': 'nbd-server-stop' }
> > 
> > +Promote Secondary to Primary:
> > +  see COLO-FT.txt
> > +
> >  TODO:
> > -1. Continuous block replication
> > -2. Shared disk
> > +1. Shared disk
> > --
> > 2.20.1  

RE: [PATCH v5 4/4] colo: Update Documentation for continuous replication

[Zhang, Chen]

> -----Original Message-----
> From: Lukas Straub <lukasstraub2@web.de>
> Sent: Saturday, September 28, 2019 9:25 PM
> To: Zhang, Chen <chen.zhang@intel.com>
> Cc: qemu-devel <qemu-devel@nongnu.org>; Jason Wang
> <jasowang@redhat.com>; Wen Congyang <wencongyang2@huawei.com>;
> Xie Changlong <xiechanglong.d@gmail.com>; kwolf@redhat.com;
> mreitz@redhat.com
> Subject: Re: [PATCH v5 4/4] colo: Update Documentation for continuous
> replication
> 
> On Thu, 26 Sep 2019 17:27:35 +0000
> "Zhang, Chen" <chen.zhang@intel.com> wrote:
> 
> > > -----Original Message-----
> > > From: Lukas Straub <lukasstraub2@web.de>
> > > Sent: Monday, September 16, 2019 3:20 AM
> > > To: qemu-devel <qemu-devel@nongnu.org>
> > > Cc: Zhang, Chen <chen.zhang@intel.com>; Jason Wang
> > > <jasowang@redhat.com>; Wen Congyang
> <wencongyang2@huawei.com>; Xie
> > > Changlong <xiechanglong.d@gmail.com>; kwolf@redhat.com;
> > > mreitz@redhat.com
> > > Subject: [PATCH v5 4/4] colo: Update Documentation for continuous
> > > replication
> > >
> > > Document the qemu command-line and qmp commands for continuous
> > > replication
> > >
> > > Signed-off-by: Lukas Straub <lukasstraub2@web.de>
> > > ---
> > >  docs/COLO-FT.txt           | 212 +++++++++++++++++++++++++++----------
> > >  docs/block-replication.txt |  28 +++--
> > >  2 files changed, 173 insertions(+), 67 deletions(-)
> > >
> > > diff --git a/docs/COLO-FT.txt b/docs/COLO-FT.txt index
> > > ad24680d13..e98c95ca2b 100644
> > > --- a/docs/COLO-FT.txt
> > > +++ b/docs/COLO-FT.txt
> > > @@ -145,35 +145,65 @@ The diagram just shows the main qmp
> command,
> > > you can get the detail  in test procedure.
> > >
> > >  == Test procedure ==
> > > -1. Startup qemu
> > > -Primary:
> > > -# qemu-system-x86_64 -accel kvm -m 2048 -smp 2 -qmp stdio -name
> > > primary \
> > > -  -device piix3-usb-uhci -vnc :7 \
> > > -  -device usb-tablet -netdev tap,id=hn0,vhost=off \
> > > -  -device virtio-net-pci,id=net-pci0,netdev=hn0 \
> > > -  -drive
> > > if=virtio,id=primary-disk0,driver=quorum,read-pattern=fifo,vote-
> > > threshold=1,\
> > > -         children.0.file.filename=1.raw,\
> > > -         children.0.driver=raw -S
> > > -Secondary:
> > > -# qemu-system-x86_64 -accel kvm -m 2048 -smp 2 -qmp stdio -name
> > > secondary \
> > > -  -device piix3-usb-uhci -vnc :7 \
> > > -  -device usb-tablet -netdev tap,id=hn0,vhost=off \
> > > -  -device virtio-net-pci,id=net-pci0,netdev=hn0 \
> > > -  -drive
> > > if=none,id=secondary-disk0,file.filename=1.raw,driver=raw,node-
> > > name=node0 \
> > > -  -drive if=virtio,id=active-disk0,driver=replication,mode=secondary,\
> > > -         file.driver=qcow2,top-id=active-disk0,\
> > > -         file.file.filename=/mnt/ramfs/active_disk.img,\
> > > -         file.backing.driver=qcow2,\
> > > -         file.backing.file.filename=/mnt/ramfs/hidden_disk.img,\
> > > -         file.backing.backing=secondary-disk0 \
> > > -  -incoming tcp:0:8888
> > > -
> > > -2. On Secondary VM's QEMU monitor, issue command
> > > +Note: Here we are running both instances on the same Machine for
> > > +testing, change the IP Addresses if you want to run it on two Hosts
> > > +
> > > +== Startup qemu ==
> > > +1. Primary:
> > > +# imagefolder="/mnt/vms/colo-test"
> > > +
> > > +The disks for the primary and secondary need to be the same before
> > > +starting colo # cp --reflink=auto $imagefolder/primary.qcow2
> > > +$imagefolder/primary-copy.qcow2
> > > +
> > > +# qemu-system-x86_64 -enable-kvm -cpu qemu64,+kvmclock -m 512 -
> smp
> > > 1 -qmp stdio \
> > > +   -vnc :0 -device piix3-usb-uhci -device usb-tablet -name primary \
> > > +   -netdev
> > > + tap,id=hn0,vhost=off,helper=/usr/lib/qemu/qemu-bridge-helper
> > > \
> > > +   -device rtl8139,id=e0,netdev=hn0 \
> > > +   -chardev socket,id=mirror0,host=127.0.0.1,port=9003,server,nowait \
> > > +   -chardev socket,id=compare1,host=127.0.0.1,port=9004,server,wait \
> > > +   -chardev socket,id=compare0,host=127.0.0.1,port=9001,server,nowait
> \
> > > +   -chardev socket,id=compare0-0,host=127.0.0.1,port=9001 \
> > > +   -chardev
> > > + socket,id=compare_out,host=127.0.0.1,port=9005,server,nowait
> > > \
> > > +   -chardev socket,id=compare_out0,host=127.0.0.1,port=9005 \
> > > +   -object filter-mirror,id=m0,netdev=hn0,queue=tx,outdev=mirror0 \
> > > +   -object filter-
> > > redirector,netdev=hn0,id=redire0,queue=rx,indev=compare_out \
> > > +   -object filter-
> > > redirector,netdev=hn0,id=redire1,queue=rx,outdev=compare0 \
> > > +   -object iothread,id=iothread1 \
> > > +   -object
> > > +colo-compare,id=comp0,primary_in=compare0-
> > > 0,secondary_in=compare1,\
> > > +outdev=compare_out0,iothread=iothread1 \
> > > +   -drive
> > > +if=ide,id=colo-disk0,driver=quorum,read-pattern=fifo,vote-threshold
> > > +=1,\
> > > +children.0.file.filename=$imagefolder/primary.qcow2,children.0.driv
> > > +er=q
> > > +cow2 -S
> > > +
> > > +2. Secondary:
> > > +# imagefolder="/mnt/vms/colo-test"
> > > +
> > > +# qemu-img create -f qcow2 $imagefolder/secondary-active.qcow2 10G
> > > +
> > > +# qemu-img create -f qcow2 $imagefolder/secondary-hidden.qcow2
> 10G
> > > +
> > > +# qemu-system-x86_64 -enable-kvm -cpu qemu64,+kvmclock -m 512 -
> smp
> > > 1 -qmp stdio \
> > > +   -vnc :1 -device piix3-usb-uhci -device usb-tablet -name secondary \
> > > +   -netdev
> > > + tap,id=hn0,vhost=off,helper=/usr/lib/qemu/qemu-bridge-helper
> > > \
> > > +   -device rtl8139,id=e0,netdev=hn0 \
> > > +   -chardev socket,id=red0,host=127.0.0.1,port=9003,reconnect=1 \
> > > +   -chardev socket,id=red1,host=127.0.0.1,port=9004,reconnect=1 \
> > > +   -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 \
> > > +   -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 \
> > > +   -object filter-rewriter,id=rew0,netdev=hn0,queue=all \
> > > +   -drive if=none,id=parent0,file.filename=$imagefolder/primary-
> > > copy.qcow2,driver=qcow2 \
> > > +   -drive
> > > +if=none,id=childs0,driver=replication,mode=secondary,file.driver=qc
> > > +ow2,
> > > +\
> > > +top-id=childs0,file.file.filename=$imagefolder/secondary-active.qco
> > > +w2,\
> > > +file.backing.driver=qcow2,file.backing.file.filename=$imagefolder/s
> > > +econ
> > > +dary-hidden.qcow2,\
> > > +file.backing.backing=parent0 \
> > > +   -drive
> > > +if=ide,id=colo-disk0,driver=quorum,read-pattern=fifo,vote-threshold
> > > +=1,\
> > > +children.0=childs0 \
> > > +   -incoming tcp:0:9998
> > > +
> >
> > I know in your COLO test environment, all the node running in same
> > physical machine, but current COLO start parameter demo easy to
> misunderstand users.
> > I think we can introduce primary node as 192.168.1.1, secondary node as
> 192.168.1.2.
> > Same issue for the VM image, we should avoid the "primary-copy.qow2".
> > Make two node independent is more clear.
> >
> 
> Ok, I will remove the primary-copy stuff. But I have a better idea for the IP
> addresses:
> Using 127.0.0.1 for Primary and 127.0.0.2 for Secondary. Both point to
> localhost, making quick testing by simple copy-paste possible when using
> different values for the imagefolder Variable. At the same time Users see
> which IP to substitute for the remote node when using multiple Hosts and
> we avoid the confusion with primary-copy.
> What do you think?
> 

I think it is a good idea~

Thanks
Zhang Chen

> >
> > > +
> > > +3. On Secondary VM's QEMU monitor, issue command
> > >  {'execute':'qmp_capabilities'}
> > > -{ 'execute': 'nbd-server-start',
> > > -  'arguments': {'addr': {'type': 'inet', 'data': {'host': 'xx.xx.xx.xx', 'port':
> > > '8889'} } } -}
> > > -{'execute': 'nbd-server-add', 'arguments': {'device':
> > > 'secondary-disk0',
> > > 'writable': true } }
> > > +{'execute': 'nbd-server-start', 'arguments': {'addr': {'type':
> > > +'inet',
> > > +'data': {'host': '127.0.0.1', 'port': '9999'} } } }
> > > +{'execute': 'nbd-server-add', 'arguments': {'device': 'parent0',
> > > +'writable': true } }
> > >
> > >  Note:
> > >    a. The qmp command nbd-server-start and nbd-server-add must be
> > > run @@ -182,44 +212,112 @@ Note:
> > >       same.
> > >    c. It is better to put active disk and hidden disk in ramdisk.
> > >
> > > -3. On Primary VM's QEMU monitor, issue command:
> > > +4. On Primary VM's QEMU monitor, issue command:
> > >  {'execute':'qmp_capabilities'}
> > > -{ 'execute': 'human-monitor-command',
> > > -  'arguments': {'command-line': 'drive_add -n buddy
> > > driver=replication,mode=primary,file.driver=nbd,file.host=xx.xx.xx.x
> > > x,file.p
> > > ort=8889,file.export=secondary-disk0,node-name=nbd_client0'}}
> > > -{ 'execute':'x-blockdev-change', 'arguments':{'parent':
> > > 'primary-disk0',
> > > 'node': 'nbd_client0' } } -{ 'execute': 'migrate-set-capabilities',
> > > -      'arguments': {'capabilities': [ {'capability': 'x-colo', 'state': true } ] } }
> > > -{ 'execute': 'migrate', 'arguments': {'uri': 'tcp:xx.xx.xx.xx:8888'
> > > } }
> > > +{'execute': 'human-monitor-command', 'arguments': {'command-line':
> > > +'drive_add -n buddy
> > > +driver=replication,mode=primary,file.driver=nbd,file.host=127.0.0.1
> > > +,fil e.port=9999,file.export=parent0,node-name=replication0'}}
> > > +{'execute': 'x-blockdev-change', 'arguments':{'parent':
> > > +'colo-disk0',
> > > +'node': 'replication0' } }
> > > +{'execute': 'migrate-set-capabilities', 'arguments':
> > > +{'capabilities': [
> > > +{'capability': 'x-colo', 'state': true } ] } }
> > > +{'execute': 'migrate', 'arguments': {'uri': 'tcp:127.0.0.1:9998' }
> > > +}
> > >
> > >    Note:
> > >    a. There should be only one NBD Client for each primary disk.
> > > -  b. xx.xx.xx.xx is the secondary physical machine's hostname or IP
> > > -  c. The qmp command line must be run after running qmp command
> > > line in
> > > +  b. The qmp command line must be run after running qmp command
> > > + line in
> > >       secondary qemu.
> > >
> > > -4. After the above steps, you will see, whenever you make changes
> > > to PVM, SVM will be synced.
> > > +5. After the above steps, you will see, whenever you make changes
> > > +to PVM,
> > > SVM will be synced.
> > >  You can issue command '{ "execute": "migrate-set-parameters" ,
> > > "arguments":{ "x-checkpoint-delay": 2000 } }'
> > > -to change the checkpoint period time
> > > +to change the idle checkpoint period time
> > > +
> > > +6. Failover test
> > > +You can kill one of the VMs and Failover on the surviving VM:
> > > +
> > > +If you killed the Secondary, then follow "Primary Failover". After
> > > +that, if you want to resume the replication, follow "Primary resume
> > > replication"
> > > +
> > > +If you killed the Primary, then follow "Secondary Failover". After
> > > +that, if you want to resume the replication, follow "Secondary
> > > +resume
> > > replication"
> > > +
> > > +== Primary Failover ==
> > > +The Secondary died, resume on the Primary
> > > +
> > > +{'execute': 'x-blockdev-change', 'arguments':{ 'parent':
> > > +'colo-disk0',
> > > +'child': 'children.1'} }
> > > +{'execute': 'human-monitor-command', 'arguments':{ 'command-line':
> > > +'drive_del replication0' } }
> > > +{'execute': 'object-del', 'arguments':{ 'id': 'comp0' } }
> > > +{'execute': 'object-del', 'arguments':{ 'id': 'iothread1' } }
> > > +{'execute': 'object-del', 'arguments':{ 'id': 'm0' } }
> > > +{'execute': 'object-del', 'arguments':{ 'id': 'redire0' } }
> > > +{'execute': 'object-del', 'arguments':{ 'id': 'redire1' } }
> > > +{'execute': 'x-colo-lost-heartbeat' }
> > > +
> > > +== Secondary Failover ==
> > > +The Primary died, resume on the Secondary and prepare to become the
> > > new
> > > +Primary
> > > +
> > > +{'execute': 'nbd-server-stop'}
> > > +{'execute': 'x-colo-lost-heartbeat'}
> > > +
> > > +{'execute': 'object-del', 'arguments':{ 'id': 'f2' } }
> > > +{'execute': 'object-del', 'arguments':{ 'id': 'f1' } }
> > > +{'execute': 'chardev-remove', 'arguments':{ 'id': 'red1' } }
> > > +{'execute': 'chardev-remove', 'arguments':{ 'id': 'red0' } }
> > > +
> > > +{'execute': 'chardev-add', 'arguments':{ 'id': 'mirror0', 'backend':
> > > +{'type': 'socket', 'data': {'addr': { 'type': 'inet', 'data': { 'host':
> > > +'127.0.0.1', 'port': '9003' } }, 'server': true } } } }
> > > +{'execute': 'chardev-add', 'arguments':{ 'id': 'compare1', 'backend':
> > > +{'type': 'socket', 'data': {'addr': { 'type': 'inet', 'data': { 'host':
> > > +'127.0.0.1', 'port': '9004' } }, 'server': true } } } }
> > > +{'execute': 'chardev-add', 'arguments':{ 'id': 'compare0', 'backend':
> > > +{'type': 'socket', 'data': {'addr': { 'type': 'inet', 'data': { 'host':
> > > +'127.0.0.1', 'port': '9001' } }, 'server': true } } } }
> > > +{'execute': 'chardev-add', 'arguments':{ 'id': 'compare0-0', 'backend':
> > > +{'type': 'socket', 'data': {'addr': { 'type': 'inet', 'data': { 'host':
> > > +'127.0.0.1', 'port': '9001' } }, 'server': false } } } }
> > > +{'execute': 'chardev-add', 'arguments':{ 'id': 'compare_out',
> > > +'backend': {'type': 'socket', 'data': {'addr': { 'type': 'inet',
> > > +'data': { 'host': '127.0.0.1', 'port': '9005' } }, 'server': true }
> > > +} } }
> > > +{'execute': 'chardev-add', 'arguments':{ 'id': 'compare_out0',
> > > +'backend': {'type': 'socket', 'data': {'addr': { 'type': 'inet',
> > > +'data': { 'host': '127.0.0.1', 'port': '9005' } }, 'server': false
> > > +} } } }
> > > +
> > > +== Primary resume replication ==
> > > +Resume replication after new Secondary is up.
> > > +
> > > +Start the new Secondary (Steps 2 and 3 above), then:
> >
> > Please note here the "then" is the original secondary node.
> > It is easy to misunderstand here.
> 
> Ok, I will make this more clear.
> 
> > > +{'execute': 'drive-mirror', 'arguments':{ 'device': 'colo-disk0',
> > > +'job-id': 'resync', 'target': 'nbd://127.0.0.1:9999/parent0', 'mode':
> > > +'existing', 'format': 'raw', 'sync': 'full'} }
> > > +
> >
> > As I mentioned before, the 'nbd://127.0.0.1:9999/parent0' is very confusing,
> user don't know which node will be connected.
> >
> > > +Wait until disk is synced, then:
> > > +{'execute': 'stop'}
> > > +{'execute': 'block-job-cancel', 'arguments':{ 'device': 'resync'} }
> > > +
> > > +{'execute': 'human-monitor-command', 'arguments':{ 'command-line':
> > > +'drive_add -n buddy
> > > +driver=replication,mode=primary,file.driver=nbd,file.host=127.0.0.1
> > > +,fil e.port=9999,file.export=parent0,node-name=replication0'}}
> > > +{'execute': 'x-blockdev-change', 'arguments':{ 'parent':
> > > +'colo-disk0',
> > > +'node': 'replication0' } }
> > > +
> > > +{'execute': 'object-add', 'arguments':{ 'qom-type':
> > > +'filter-mirror',
> > > +'id': 'm0', 'props': { 'netdev': 'hn0', 'queue': 'tx', 'outdev':
> > > +'mirror0' } } }
> > > +{'execute': 'object-add', 'arguments':{ 'qom-type':
> > > +'filter-redirector', 'id': 'redire0', 'props': { 'netdev': 'hn0',
> > > +'queue': 'rx', 'indev': 'compare_out' } } }
> > > +{'execute': 'object-add', 'arguments':{ 'qom-type':
> > > +'filter-redirector', 'id': 'redire1', 'props': { 'netdev': 'hn0',
> > > +'queue': 'rx', 'outdev': 'compare0' } } }
> > > +{'execute': 'object-add', 'arguments':{ 'qom-type': 'iothread', 'id':
> > > +'iothread1' } }
> > > +{'execute': 'object-add', 'arguments':{ 'qom-type': 'colo-compare',
> > > +'id': 'comp0', 'props': { 'primary_in': 'compare0-0', 'secondary_in':
> > > +'compare1', 'outdev': 'compare_out0', 'iothread': 'iothread1' } } }
> > > +
> > > +{'execute': 'migrate-set-capabilities', 'arguments':{
> > > +'capabilities': [
> > > +{'capability': 'x-colo', 'state': true } ] } }
> > > +{'execute': 'migrate', 'arguments':{ 'uri': 'tcp:127.0.0.1:9998' }
> > > +}
> > > +
> >
> > The guest network have issues here in my test, I can't ping the guest from
> the host.
> > Is it works in your test environment?
> 
> Yes, it works for me (based on v4.1.0). I simply copy-paste everything here
> 1:1 for testing.
> 
> Regards,
> Lukas Straub
> 
> > By the way, after finish this doc we can sync it to Qemu COLO WIKI page.
> >
> > Thanks
> > Zhang Chen
> >
> >
> > > +Note:
> > > +If this Primary previously was a Secondary, then we need to insert
> > > +the filters before the filter-rewriter by using the
> > > +"'insert': 'before', 'position': 'rew0'" Options. See below.
> > > +
> > > +== Secondary resume replication ==
> > > +Become Primary and resume replication after new Secondary is up.
> > > +
> > > +Start the new Secondary (Steps 2 and 3 above, but with different
> > > +image than
> > > +primary-copy.qcow2 and different VNC port), then:
> > > +{'execute': 'drive-mirror', 'arguments':{ 'device': 'colo-disk0',
> > > +'job-id': 'resync', 'target': 'nbd://127.0.0.1:9999/parent0', 'mode':
> > > +'existing', 'format': 'raw', 'sync': 'full'} }
> > > +
> > > +Wait until disk is synced, then:
> > > +{'execute': 'stop'}
> > > +{'execute': 'block-job-cancel', 'arguments':{ 'device': 'resync' }
> > > +}
> > >
> > > -5. Failover test
> > > -You can kill Primary VM and run 'x_colo_lost_heartbeat' in
> > > Secondary VM's - monitor at the same time, then SVM will failover
> > > and client will not detect this -change.
> > > +{'execute': 'human-monitor-command', 'arguments':{ 'command-line':
> > > +'drive_add -n buddy
> > > +driver=replication,mode=primary,file.driver=nbd,file.host=127.0.0.1
> > > +,fil e.port=9999,file.export=parent0,node-name=replication0'}}
> > > +{'execute': 'x-blockdev-change', 'arguments':{ 'parent':
> > > +'colo-disk0',
> > > +'node': 'replication0' } }
> > >
> > > -Before issuing '{ "execute": "x-colo-lost-heartbeat" }' command, we
> > > have to -issue block related command to stop block replication.
> > > -Primary:
> > > -  Remove the nbd child from the quorum:
> > > -  { 'execute': 'x-blockdev-change', 'arguments': {'parent': 'colo-disk0',
> 'child':
> > > 'children.1'}}
> > > -  { 'execute': 'human-monitor-command','arguments': {'command-line':
> > > 'drive_del blk-buddy0'}}
> > > -  Note: there is no qmp command to remove the blockdev now
> > > +{'execute': 'object-add', 'arguments':{ 'qom-type':
> > > +'filter-mirror',
> > > +'id': 'm0', 'props': { 'insert': 'before', 'position': 'id=rew0',
> > > +'netdev': 'hn0', 'queue': 'tx', 'outdev': 'mirror0' } } }
> > > +{'execute': 'object-add', 'arguments':{ 'qom-type':
> > > +'filter-redirector', 'id': 'redire0', 'props': { 'insert':
> > > +'before',
> > > +'position': 'id=rew0', 'netdev': 'hn0', 'queue': 'rx', 'indev':
> > > +'compare_out' } } }
> > > +{'execute': 'object-add', 'arguments':{ 'qom-type':
> > > +'filter-redirector', 'id': 'redire1', 'props': { 'insert':
> > > +'before',
> > > +'position': 'id=rew0', 'netdev': 'hn0', 'queue': 'rx', 'outdev':
> > > +'compare0' } } }
> > > +{'execute': 'object-add', 'arguments':{ 'qom-type': 'iothread', 'id':
> > > +'iothread1' } }
> > > +{'execute': 'object-add', 'arguments':{ 'qom-type': 'colo-compare',
> > > +'id': 'comp0', 'props': { 'primary_in': 'compare0-0', 'secondary_in':
> > > +'compare1', 'outdev': 'compare_out0', 'iothread': 'iothread1' } } }
> > >
> > > -Secondary:
> > > -  The primary host is down, so we should do the following thing:
> > > -  { 'execute': 'nbd-server-stop' }
> > > +{'execute': 'migrate-set-capabilities', 'arguments':{
> > > +'capabilities': [
> > > +{'capability': 'x-colo', 'state': true } ] } }
> > > +{'execute': 'migrate', 'arguments':{ 'uri': 'tcp:127.0.0.1:9998' }
> > > +}
> > >
> > >  == TODO ==
> > > -1. Support continuous VM replication.
> > > -2. Support shared storage.
> > > -3. Develop the heartbeat part.
> > > -4. Reduce checkpoint VM’s downtime while doing checkpoint.
> > > +1. Support shared storage.
> > > +2. Develop the heartbeat part.
> > > +3. Reduce checkpoint VM’s downtime while doing checkpoint.
> > > diff --git a/docs/block-replication.txt b/docs/block-replication.txt
> > > index
> > > 6bde6737fb..108e9166a8 100644
> > > --- a/docs/block-replication.txt
> > > +++ b/docs/block-replication.txt
> > > @@ -65,12 +65,12 @@ blocks that are already in QEMU.
> > >               ^            ||                            .----------
> > >               |            ||                            | Secondary
> > >          1 Quorum          ||                            '----------
> > > -         /      \         ||
> > > -        /        \        ||
> > > -   Primary    2 filter
> > > -     disk         ^                                                             virtio-blk
> > > -                  |                                                                  ^
> > > -                3 NBD  ------->  3 NBD                                               |
> > > +         /      \         ||                                                           virtio-blk
> > > +        /        \        ||                                                               ^
> > > +   Primary    2 filter                                                                     |
> > > +     disk         ^                                                                   7 Quorum
> > > +                  |                                                                    /
> > > +                3 NBD  ------->  3 NBD                                                /
> > >                  client    ||     server                                          2 filter
> > >                            ||        ^                                                ^
> > >  --------.                 ||        |                                                |
> > > @@ -106,6 +106,10 @@ any state that would otherwise be lost by the
> > > speculative write-through  of the NBD server into the secondary
> > > disk. So before block replication,  the primary disk and secondary
> > > disk should contain the same data.
> > >
> > > +7) The secondary also has a quorum node, so after secondary
> > > +failover it can become the new primary and continue replication.
> > > +
> > > +
> > >  == Failure Handling ==
> > >  There are 7 internal errors when block replication is running:
> > >  1. I/O error on primary disk
> > > @@ -171,16 +175,18 @@ Primary:
> > >       leading whitespace.
> > >    5. The qmp command line must be run after running qmp command line
> in
> > >       secondary qemu.
> > > -  6. After failover we need remove children.1 (replication driver).
> > > +  6. After primary failover we need remove children.1 (replication driver).
> > >
> > >  Secondary:
> > >    -drive if=none,driver=raw,file.filename=1.raw,id=colo1 \
> > > -  -drive if=xxx,id=topxxx,driver=replication,mode=secondary,top-
> > > id=topxxx\
> > > +  -drive
> > > + if=none,id=childs1,driver=replication,mode=secondary,top-id=childs
> > > + 1
> > >           file.file.filename=active_disk.qcow2,\
> > >           file.driver=qcow2,\
> > >           file.backing.file.filename=hidden_disk.qcow2,\
> > >           file.backing.driver=qcow2,\
> > >           file.backing.backing=colo1
> > > +  -drive if=xxx,driver=quorum,read-pattern=fifo,id=top-disk1,\
> > > +         vote-threshold=1,children.0=childs1
> > >
> > >    Then run qmp command in secondary qemu:
> > >      { 'execute': 'nbd-server-start', @@ -234,6 +240,8 @@ Secondary:
> > >    The primary host is down, so we should do the following thing:
> > >    { 'execute': 'nbd-server-stop' }
> > >
> > > +Promote Secondary to Primary:
> > > +  see COLO-FT.txt
> > > +
> > >  TODO:
> > > -1. Continuous block replication
> > > -2. Shared disk
> > > +1. Shared disk
> > > --
> > > 2.20.1

RE: [PATCH v5 2/4] tests/test-replication.c: Add test for ignoring requests after failover

[Zhang, Chen]

> -----Original Message-----
> From: Lukas Straub <lukasstraub2@web.de>
> Sent: Saturday, September 28, 2019 7:07 PM
> To: Zhang, Chen <chen.zhang@intel.com>
> Cc: qemu-devel <qemu-devel@nongnu.org>; Jason Wang
> <jasowang@redhat.com>; Wen Congyang <wencongyang2@huawei.com>;
> Xie Changlong <xiechanglong.d@gmail.com>; kwolf@redhat.com;
> mreitz@redhat.com
> Subject: Re: [PATCH v5 2/4] tests/test-replication.c: Add test for ignoring
> requests after failover
> 
> On Thu, 26 Sep 2019 17:40:03 +0000
> "Zhang, Chen" <chen.zhang@intel.com> wrote:
> 
> > > -----Original Message-----
> > > From: Lukas Straub <lukasstraub2@web.de>
> > > Sent: Monday, September 16, 2019 3:20 AM
> > > To: qemu-devel <qemu-devel@nongnu.org>
> > > Cc: Zhang, Chen <chen.zhang@intel.com>; Jason Wang
> > > <jasowang@redhat.com>; Wen Congyang
> <wencongyang2@huawei.com>; Xie
> > > Changlong <xiechanglong.d@gmail.com>; kwolf@redhat.com;
> > > mreitz@redhat.com
> > > Subject: [PATCH v5 2/4] tests/test-replication.c: Add test for
> > > ignoring requests after failover
> > >
> > > This simulates the case that happens when we resume COLO after
> failover.
> > >
> >
> > It looks change the title to "Add test for secondary node continuous
> backup" is better.
> 
> Did you mean "continuous replication"? Would "Add test for secondary node
> continuing replication" be Ok?

OK for me.

Thanks
Zhang Chen

> 
> > > Signed-off-by: Lukas Straub <lukasstraub2@web.de>
> > > ---
> > >  tests/test-replication.c | 52
> > > ++++++++++++++++++++++++++++++++++++++++
> > >  1 file changed, 52 insertions(+)
> > >
> > > diff --git a/tests/test-replication.c b/tests/test-replication.c
> > > index
> > > f085d1993a..5addfc2227 100644
> > > --- a/tests/test-replication.c
> > > +++ b/tests/test-replication.c
> > > @@ -489,6 +489,56 @@ static void test_secondary_stop(void)
> > >      teardown_secondary();
> > >  }
> > >
> > > +static void test_secondary_failover_then_ignore_requests(void)
> >
> > Same as title, I think change to "test_secondary_continuous_backup" is
> more clear.
> >
> > Thanks
> > Zhang Chen
> >
> > > +{
> > > +    BlockBackend *top_blk, *local_blk;
> > > +    Error *local_err = NULL;
> > > +
> > > +    top_blk = start_secondary();
> > > +    replication_start_all(REPLICATION_MODE_SECONDARY, &local_err);
> > > +    g_assert(!local_err);
> > > +
> > > +    /* write 0x22 to s_local_disk (IMG_SIZE / 2, IMG_SIZE) */
> > > +    local_blk = blk_by_name(S_LOCAL_DISK_ID);
> > > +    test_blk_write(local_blk, 0x22, IMG_SIZE / 2, IMG_SIZE / 2,
> > > + false);
> > > +
> > > +    /* replication will backup s_local_disk to s_hidden_disk */
> > > +    test_blk_read(top_blk, 0x11, IMG_SIZE / 2,
> > > +                  IMG_SIZE / 2, 0, IMG_SIZE, false);
> > > +
> > > +    /* write 0x33 to s_active_disk (0, IMG_SIZE / 2) */
> > > +    test_blk_write(top_blk, 0x33, 0, IMG_SIZE / 2, false);
> > > +
> > > +    /* do failover (active commit) */
> > > +    replication_stop_all(true, &local_err);
> > > +    g_assert(!local_err);
> > > +
> > > +    /* it should ignore all requests from now on */
> > > +
> > > +    /* start after failover */
> > > +    replication_start_all(REPLICATION_MODE_PRIMARY, &local_err);
> > > +    g_assert(!local_err);
> > > +
> > > +    /* checkpoint */
> > > +    replication_do_checkpoint_all(&local_err);
> > > +    g_assert(!local_err);
> > > +
> > > +    /* stop */
> > > +    replication_stop_all(true, &local_err);
> > > +    g_assert(!local_err);
> > > +
> > > +    /* read from s_local_disk (0, IMG_SIZE / 2) */
> > > +    test_blk_read(top_blk, 0x33, 0, IMG_SIZE / 2,
> > > +                  0, IMG_SIZE / 2, false);
> > > +
> > > +
> > > +    /* read from s_local_disk (IMG_SIZE / 2, IMG_SIZE) */
> > > +    test_blk_read(top_blk, 0x22, IMG_SIZE / 2,
> > > +                  IMG_SIZE / 2, 0, IMG_SIZE, false);
> > > +
> > > +    teardown_secondary();
> > > +}
> > > +
> > >  static void test_secondary_do_checkpoint(void)
> > >  {
> > >      BlockBackend *top_blk, *local_blk; @@ -584,6 +634,8 @@ int
> > > main(int argc, char **argv)
> > >      g_test_add_func("/replication/secondary/write",
> test_secondary_write);
> > >      g_test_add_func("/replication/secondary/start",
> test_secondary_start);
> > >      g_test_add_func("/replication/secondary/stop",
> > > test_secondary_stop);
> > > +
> > > g_test_add_func("/replication/secondary/failover_then_ignore_request
> > > s",
> > > +                    test_secondary_failover_then_ignore_requests);
> > >      g_test_add_func("/replication/secondary/do_checkpoint",
> > >                      test_secondary_do_checkpoint);
> > >      g_test_add_func("/replication/secondary/get_error_all",
> > > --
> > > 2.20.1
> >

RE: [PATCH v5 3/4] net/filter.c: Add Options to insert filters anywhere in the filter list

[Zhang, Chen]

> -----Original Message-----
> From: Lukas Straub <lukasstraub2@web.de>
> Sent: Saturday, September 28, 2019 6:45 PM
> To: Zhang, Chen <chen.zhang@intel.com>
> Cc: qemu-devel <qemu-devel@nongnu.org>; Jason Wang
> <jasowang@redhat.com>; Wen Congyang <wencongyang2@huawei.com>;
> Xie Changlong <xiechanglong.d@gmail.com>; kwolf@redhat.com;
> mreitz@redhat.com
> Subject: Re: [PATCH v5 3/4] net/filter.c: Add Options to insert filters
> anywhere in the filter list
> 
> On Thu, 26 Sep 2019 17:02:58 +0000
> "Zhang, Chen" <chen.zhang@intel.com> wrote:
> > > diff --git a/qemu-options.hx b/qemu-options.hx index
> > > 08749a3391..23fa5a344e 100644
> > > --- a/qemu-options.hx
> > > +++ b/qemu-options.hx
> > > @@ -4368,7 +4368,7 @@ applications, they can do this through this
> > > parameter. Its format is  a gnutls priority string as described at
> > > @url{https://gnutls.org/manual/html_node/Priority-Strings.html}.
> > >
> > > -@item -object filter-
> > >
> buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,queue=@va
> > > r{
> > > all|rx|tx}][,status=@var{on|off}]
> > > +@item -object
> > > +filter-buffer,id=@var{id},netdev=@var{netdevid},interval=@var{t}[,q
> > > +ueue
> > > +=@var{all|rx|tx}][,status=@var{on|off}][,position=@var{head|tail|id
> > > +=<id
> > > +>}][,insert=@var{behind|before}]
> > >
> > >  Interval @var{t} can't be 0, this filter batches the packet
> > > delivery: all  packets arriving in a given interval on netdev
> > > @var{netdevid} are delayed @@ -
> > > 4387,11 +4387,11 @@ queue @var{all|rx|tx} is an option that can be
> > > applied to any netfilter.
> > >  @option{tx}: the filter is attached to the transmit queue of the netdev,
> > >               where it will receive packets sent by the netdev.
> > >
> > > -@item -object filter-
> > >
> mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardevid},queu
> > > e
> > > =@var{all|rx|tx}[,vnet_hdr_support]
> > > +@item -object
> > > +filter-
> mirror,id=@var{id},netdev=@var{netdevid},outdev=@var{chardev
> > > +id},
> > > +queue=@var{all|rx|tx}[,vnet_hdr_support][,position=@var{head|tail|i
> > > +d=<
> > > i
> > > +d>}][,insert=@var{behind|before}]
> > >
> > >  filter-mirror on netdev @var{netdevid},mirror net packet to
> > > chardev@var{chardevid}, if it has the vnet_hdr_support flag,
> > > filter-mirror will mirror packet with vnet_hdr_len.
> > >
> >
> > Please add description for the newly added parameter in each filter.
> > After that:
> > Reviewed-by: Zhang Chen <chen.zhang@intel.com>
> >
> > Thanks
> > Zhang Chen
> 
> Hi,
> I will add a single description like its currently done with the "queue" option,
> noting that it applies to any netfilter. Is that Ok?

It is enough for me.

Thanks
Zhang Chen

> 
> Regards,
> Lukas Straub
> 
> >
> > > -@item -object filter-
> > >
> redirector,id=@var{id},netdev=@var{netdevid},indev=@var{chardevid},o
> > > ut dev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support]
> > > +@item -object
> > > +filter-redirector,id=@var{id},netdev=@var{netdevid},indev=@var{char
> > > +devi
> > >
> +d},outdev=@var{chardevid},queue=@var{all|rx|tx}[,vnet_hdr_support][
> > > +,p
> > > os
> > > +ition=@var{head|tail|id=<id>}][,insert=@var{behind|before}]
> > >
> > >  filter-redirector on netdev @var{netdevid},redirect filter's net
> > > packet to chardev  @var{chardevid},and redirect indev's packet to
> > > filter.if it has the vnet_hdr_support flag, @@ -4400,7 +4400,7 @@
> > > Create a filter-redirector we need to differ outdev id from indev
> > > id, id can not  be the same. we can just use indev or outdev, but at
> > > least one of indev or outdev  need to be specified.
> > >
> > > -@item -object filter-
> > > rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx|tx},[vn
> > > et_
> > > hdr_support]
> > > +@item -object
> > > +filter-rewriter,id=@var{id},netdev=@var{netdevid},queue=@var{all|rx
> > > +|tx}
> > > +,[vnet_hdr_support][,position=@var{head|tail|id=<id>}][,insert=@var
> > > +{beh
> > > +ind|before}]
> > >
> > >  Filter-rewriter is a part of COLO project.It will rewrite tcp
> > > packet to secondary from primary to keep secondary tcp
> > > connection,and rewrite @@ -
> > > 4413,7 +4413,7 @@ colo secondary:
> > >  -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1
> > >  -object filter-rewriter,id=rew0,netdev=hn0,queue=all
> > >
> > > -@item -object filter-
> > >
> dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=@var
> > > {
> > > len}]
> > > +@item -object
> > > +filter-
> > > dump,id=@var{id},netdev=@var{dev}[,file=@var{filename}][,maxlen=
> > > +@var{len}][,position=@var{head|tail|id=<id>}][,insert=@var{behind|b
> > > +efor
> > > +e}]
> > >
> > >  Dump the network traffic on netdev @var{dev} to the file specified
> > > by @var{filename}. At most @var{len} bytes (64k by default) per
> > > packet are stored.
> > > --
> > > 2.20.1
> >