* [Qemu-devel] [PATCH v3 3/4] net/filter.c: Add Options to insert filters anywhere in the filter list
2019-09-03 9:20 [Qemu-devel] [PATCH v3 0/4] colo: Add support for continious replication Lukas Straub
2019-09-03 9:20 ` [Qemu-devel] [PATCH v3 1/4] block/replication.c: Ignore requests after failover Lukas Straub
2019-09-03 9:20 ` [Qemu-devel] [PATCH v3 2/4] tests/test-replication.c: Add test for ignoring " Lukas Straub
@ 2019-09-03 9:20 ` Lukas Straub
2019-09-03 9:20 ` [Qemu-devel] [PATCH v3 4/4] colo: Update Documentation for continious replication Lukas Straub
2019-09-03 10:54 ` [Qemu-devel] [PATCH v3 0/4] colo: Add support " no-reply
4 siblings, 0 replies; 6+ messages in thread
From: Lukas Straub @ 2019-09-03 9:20 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, Wen Congyang, Jason Wang, mreitz, Zhang Chen, Xie Changlong
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 either "head", "tail" or 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 | 78 +++++++++++++++++++++++++++++++++++++++++++-
qemu-options.hx | 10 +++---
3 files changed, 84 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..7edebb2bf7 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 +262,27 @@ static void netfilter_complete(UserCreatable *uc, Error **errp)
return;
}
+ if (strcmp(nf->position, "head") && strcmp(nf->position, "tail")) {
+ /* Search for the position to insert before/behind */
+ Object *container;
+ Object *obj;
+
+ container = object_get_objects_root();
+ obj = object_resolve_path_component(container, nf->position);
+ if (!obj) {
+ error_setg(errp, "filter '%s' not found", nf->position);
+ return;
+ }
+
+ position = NETFILTER(obj);
+
+ if (position->netdev != ncs[0]) {
+ error_setg(errp, "filter '%s' belongs to a different netdev",
+ nf->position);
+ return;
+ }
+ }
+
nf->netdev = ncs[0];
if (nfc->setup) {
@@ -228,7 +292,18 @@ 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 +320,7 @@ 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..1fd294a10f 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}][,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}][,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}][,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}][,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}][,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
^ permalink raw reply related [flat|nested] 6+ messages in thread* [Qemu-devel] [PATCH v3 4/4] colo: Update Documentation for continious replication
2019-09-03 9:20 [Qemu-devel] [PATCH v3 0/4] colo: Add support for continious replication Lukas Straub
` (2 preceding siblings ...)
2019-09-03 9:20 ` [Qemu-devel] [PATCH v3 3/4] net/filter.c: Add Options to insert filters anywhere in the filter list Lukas Straub
@ 2019-09-03 9:20 ` Lukas Straub
2019-09-03 10:54 ` [Qemu-devel] [PATCH v3 0/4] colo: Add support " no-reply
4 siblings, 0 replies; 6+ messages in thread
From: Lukas Straub @ 2019-09-03 9:20 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, Wen Congyang, Jason Wang, mreitz, Zhang Chen, Xie Changlong
Document the qemu command-line and qmp commands for continious replication
Signed-off-by: Lukas Straub <lukasstraub2@web.de>
---
docs/COLO-FT.txt | 212 +++++++++++++++++++++++++++----------
docs/block-replication.txt | 26 +++--
2 files changed, 172 insertions(+), 66 deletions(-)
diff --git a/docs/COLO-FT.txt b/docs/COLO-FT.txt
index ad24680d13..30dcb45d48 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': 'rew0', 'netdev': 'hn0', 'queue': 'tx', 'outdev': 'mirror0' } } }
+{'execute': 'object-add', 'arguments':{ 'qom-type': 'filter-redirector', 'id': 'redire0', 'props': { 'insert': 'before', 'position': 'rew0', 'netdev': 'hn0', 'queue': 'rx', 'indev': 'compare_out' } } }
+{'execute': 'object-add', 'arguments':{ 'qom-type': 'filter-redirector', 'id': 'redire1', 'props': { 'insert': 'before', 'position': '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..9fc145af86 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 continiue 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',
@@ -233,7 +239,9 @@ Primary:
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
--
2.20.1
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