[Lustre-devel] LustreFS performance

[Lustre-devel] LustreFS performance

[Vitaly Fertman]

****************************************************
	LustreFS benchmarking methodology.
****************************************************

The document aims to describe the benchmarking methodology which helps
to understand the LustreFS performance and reveal LustreFS bottlenecks  
in
different configurations on different hardware, to ensure the next  
LustreFS
release does not downgrade comparing with a previous one. In other  
words:
	Goal1. Understand the HEAD performance.
	Goal2. Compare HEAD and b1_6 (b1_8) performance.

To achieve the Goal1, the methodology suggests to test different  
layers of
software in the bottom-top direction, i.e. the underlying back-end,  
the target
server sitting on this back-end, the network connected to this target  
and how
the target performs through this network, etc up to the whole cluster.
Each next step has only 1 change over the previous one, it is either a  
new layer
added or 1 parameter in the configuration is changed (probably another  
network
type or another back-end). Comparing the results of each test with the  
previous
test, we get the overhead of the added layer or the performance impact  
of
changing this parameter.

To achieve the Goal2, the methodology suggests to go in the reverse  
top-bottom
direction, i.e. to test some large sub-systems first and, if a  
downgrade vs. a previous
LustreFS version is detected, to perform more detailed tests. (This is  
considered as
the primary goal of the 2.0 Performance Team).

The document does not cover the way of fixing revealed problems,  
probably some
special purpose test needs to be run or oprofile needs to be compiled  
in -- it is our
of scope of the document.

Obviously, it is not possible to perform all the thousands of tests in  
all the configurations,
running all the special purpose tests, etc, the document tries to  
prepare:
1) all the essential and sufficient tests to see how the system  
performs in general;
2) some minimal amount of essential tests to see how the system scales  
in different
conditions.
Therefore, the plan does not guarantee we will not miss a bottleneck  
or a bug, it just
tries to cover maximum possible scenarios in most interesting  
conditions/environment
states.

The amount of tests described below is already about 2K, and there  
will be definitely more,
and it will take a lot of time to perform all of them and to analyze  
the results.  So one of
the major concerns here is how to minimize the amount of test so that  
we would not miss
some interesting case and would be able to get all the results within  
a reasonable amount of
time. Please keep it in mind while looking at the tests below.

**** Hardware Requirements. ****

The test plan implies that we change only 1 parameter (cpu or disk or  
network)
on each step. Thus, the HW requirements are:

-- at least 1 node with:
   CPU:32;
   RAM: enough to have a tmpfs for MDS;
   DISK: raid, regular.
   NET: both GiGe and IB installed.
-- besides that: 8 clients, 4 other servers.
-- the other servers include:
   DISK: raid, regular.
   NET: both GiGe and IB installed.
-- client includes:
NET: both GiGe and IB installed.

**** Software requirements ****

1. Short term.
1.1 mdsrate
to be completed to test all the operations listed in MDST3 (see below).
1.2 mdsrate-**.sh
to be fixed/written to run mdsrate properly and test all the  
operations listed in
MDST3 (see below).
1.3. fake disk
implement FAIL flag and report 'done' without doing anything in  
obdfilter to get
a low-latency disk.
1.4. MT.
add more tests here and implement them.

2. Long term.
2.1. mdtstack-survey
- an echo client-server is to be written for mds similar to ost.
- a test script similar to obdfilter-survey.sh is to be written.

**** Different configurations ****

Configuration of Node:
RAM. Amount of RAM on nodes (?)
CPU. Count of CPUs on nodes (1..32)
DISK. Disk type (regular, raid, tmpfs, fake)
JOUR. Journal type (internal, external, ram)

Q:  which raid?
A: raid5, as it seems to be the most popular.

fake: to get a low-latency disk, it is preferable to report 'done'  
without doing anything
in obdfilter once some FAIL flag is set. It is useful for OST testing,  
because first of all,
it does not have a CPU overhead of memcpy of using tmpfs and it lets  
to test large
amount of data in contrast to tmpfs. As a drawback, it skips the  
localfs code paths.

Configuration of Cluster:
CL. Amount of clients (1,2,4,8)
OSS. Amount of OSS nodes (1,2,4)
NET. Network type (GiGe, IB)
OSTN. Amount of OST per nodes (1,2,4)

Configuration of test.
TH. Amount of threads per client (1,2,4,8)
VER. Lustre version (b1_6, HEAD. later b1_8).
FEAT. Lustre features to turn off (COS, SA, RA, debug messages)
TEST. Specific test parameters.

**** Testing ****
Low Layers Testing (LLT)
LLT1. Raw disk (lustre-iokit:sgpdd-survey)
LLT2. Local filesystem (lustre-iokit: ior-survey, is fs mounted  
synchronously?)

Network Testing (NETT).
NETT1. lnet: lnetself test.
NETT2. OBD: lustre-iokit: (obdfilter-survey, 	echo_client-osc-..- 
net-..-ost-echo_server)
NETT3. MD: (not ready)

OST Testing (OSTT).
OSTT1. Isolated OST (lustre-iokit: obdfilter-survey, 	echo_client- 
obdfilter-..-disk)
OSTT2. Remote OST (lustre-iokit: obdfilter-survey,	echo_client-osc-..- 
ost-obdfilter-..-disk)
OSTT3. Client-OST IO (lustre-iokit: ost-survey, client-ost-disk).

MDS Testing (MDST).
MDST1. Isolated MDS test (not ready)
MDST2. Remote MDS test (not ready)
MDST3. Simple Client-MDS operation test

Mixed testing (MT) (not ready)

**** Statistics ****

During all the tests the following is supposed to be running on all  
the servers:
1) vmstat
2) iostat, if there is some disk activity.
smth else?

*** Goal1. Understand the HEAD performance. ***

The Goal1 describes the testing methodology in the bottom-top direction,
from the lower layers (disk) to the complete Lustre cluster.

LLT1. Raw disk (lustre-iokit:sgpdd-survey)
RAM: fixed
CPU: 1
DISK: regular,raid,tmpfs (default=raid)
JOUR:-
CL: 1
OSS:1
NET: -
OSTN:-
TH: 1,2,4,8 (default=1)
F: debug
TEST:
*)bulk size is specified as rszlo/rszhi=[1,4,64,1024K]
*)TH is specified as thrlo/thrhi=[1,2,4,8]
*)the amount of objects to work on in parallel: crglo=crghi=[1;TH]
i.e. test only cases when all the threads work on the same file and
when all of them work on a separate file.
[bulk;separate or commin dir]=8 tests;

Test matrix(TESTxTHxDISK):
Run TESTs with different amount of threads for each DISK.
TESTxTHxDISK=(8x4 - 1)x3=93 tests.
"-1" because TH=1 is already covered.

Total:93 tests.

*** NETT1. lnetself test.***

RAM: fixed
CPU: 1,2,8,32 (default=1)
DISK: -
JOUR:-
CL: 1,2,4,8 (default=1)
OSS:1
NET: GiGe, IB (default=IB)
OSTN:1
TH: 1,2,4,8 (default=1)
F: debug
TEST:
*) test type: PING,READ,WRITE tests
*) bulk size for READ/WRITE: 1k,4k,64k,1M
[1 ping + 4 reads + 4 writes] = 9 tests

Test matrix (TESTxCLxTHxNETxCPU):
1. Multi-thread test.
Run TESTs on CL=1 with different amount of threads.
TESTxTH=[1+4+4]x4=36 tests.
2. Multi-client test
2.1. Let's check how clients scale vs. threads per client (TH=1).
2.2. Let's check how the system scale with many clients and threads  
(TH=8).
Note: to be more demonstrative, the maximum amount of threads could be  
taken
<8, if TH=8 reaches the maximum network throughput with small amount  
of clients.
[CL>1;TH=1,8]. TESTxCLxTH=9x3x2=54 tests.
3. Network test
As the nature of IB is different from GiGe, we need to repeat all the  
tests
from (1,2) here. 36+54=90 tests.
4. CPU test
Note: lnet fixes from Liang to be applied here.
Run TESTs on different amount of CPU.
It is mostly interesting to look at large amount of threads, as we are
going to benefit from handling them in parallel.
At the same time, if some HW (network) limit is reached, the result  
will not be
very demonstrative, so test with 1 small & 1 large bulk size only:[1k; 
1024K]:
[CL=8,TH=1,2,4,8]. TESTxCLxTHxCPU=5x1x4x(4-1)=60.

Total: 240 tests.

*** NETT2. OBD performance ***
lustre-iokit: obdfilter-survey, case=network.
	
The results of this tests are to be compared with lnet results to get
the osc+ost+ptlrpc overhead.

RAM: fixed
CPU: 1
DISK: -
JOUR:-
CL: 1,2,4,8 (default=1)
OSS:1
NET: IB
OSTN:1
TH: 1,2,4,8 (default=1)
F: debug
TEST:
*) bulk size: rszlo=rszhi=N (1,4,64,1024)
*) TH is specified through: thrlo=1, thrhi=8 (thread count, 1,2,4,8)
*) the amount of objects is: nobjlo=nobjhi=[1;TH]
i.e. test only cases when all the threads work on the same file and
when all of them work on a separate file.
[4 bulks; common or separate dir]=8 tests

Test matrix(TESTxTHxCLxNET):
1. Multi-thread test.
Run TESTs on CL=1 with different amount of threads. TESTxTH=8x4=32 tests
2. Multi-client test
2.1. Let's check how clients scale vs. threads per client (TH=1).
2.2. Let's check how the system scale with many clients and threads  
(TH=8).
Note: to be more demonstrative, the maximum amount of threads should  
be taken
<8, if TH=8 reaches the maximum network throughput with small amount  
of clients.
[CL>1;TH=1,8]. TESTxCLxTH=8x3x2=48 tests.
3. Network test.
Having IB results in hand after (1,2) and these results from NETT1, we  
already see how
osc+ost+ptlrpc changes the behavior. There is no reason to repeat them  
for GiGe, it seems.
4.CPU test
Note: lnet fixes from Liang to be applied here.
Run TESTs on different amount of CPU.
It is mostly interesting to look at large amount of threads, as we are
going to benefit from handling them in parallel.
At the same time, if some HW (network) limit is reached, the result  
will not be
very demonstrative, so test with 1 small & 1 large bulk size only:[1k; 
1024K]:
[CL=8,TH=1,2,4,8]. TESTxCLxTHxCPU=4x1x4x(4-1)=48.

Total: 128 tests.

*** OSTT1. Isolated OST ***
lustre-iokit: obdfilter-survey, case=disk

The results of this tests are to be compared with LLT results to get  
the OST
stack overhead.

RAM: fixed
CPU: 1,2,8,32 (default=1)
DISK: regular, raid, fake (default=fake)
JOUR: int, ext, ram, (default=int)
CL: 1
OSS:1
NET: -
OSTN:1,2,4 (default=1)
TH: 1,2,4,8 (default=1)
F: debug
TEST:
*) bulk size: rszlo=rszhi=N (1,4,64,1024K)
*) TH is specified through: thrlo=1, thrhi=8 (1,2,4,8)
*) each OST is supposed to be configured on a separate disk.
*) the amount of objects is: nobjlo=nobjhi=[1;TH]
i.e. test only cases when all the threads work on the same file and
when all of them work on a separate file.
[4 bulks; common of separate dir]=8 tests

Test matrix(TESTxTHxOSTNxDISKxCPU):
1. Multi-thread test.
Run TESTs on OSTN=1 with different amount of threads. TESTxTH=8x4=32  
tests
2. Multi-OST test
2.1. Let's check how OSTs vs. threads per OST scale (TH=OSTN).
2.2. Let's check how the system scale with many OSTs and threads  
(TH=8*OSTN).
[OSTN>1;TH=OSTN,8*OSTN]. TESTxOSTNxTH=8x2x2=32 tests.
3. DISK test
As other disks are completely different, so lets repeat most of the  
(1,2) for 2 others:
[TH=OSTN;8*OSTN]: TESTxOSTNxTHxDISK=8x3x2x2=96
4. JOURNAL test.
Limit the tests with only raid-disk.
Limit the test with only 1 large and 1 small bulk:[1,1024K].
TESTxOSTNxTHxJOUR: 4x3x2x2=48
5. CPU test
Note: lnet fixes from Liang to be applied here.
Run TESTs on different amount of CPU. It is better to perform it on a  
fast
backend (DISK=fake) to see how CPU really matters.
It is mostly interesting to look at large amount of threads, as we are  
going
to benefit from handling them in parallel.
Also, run with a small & a large bulk only:[1,1024K]
[OSTN=4,TH=1,2,4,8]: TESTxOSTNxTHxCPU=4x1x4x3=48

Total: 256 tests.

*** OSTT2. Real OST test ***
lustre-iokit: obdfilter-survey, case=netdisk

This test is a composition of OBD performance and Isolated OST tests,
so its results are to be compared with NETT2 & OSTT1 results.

RAM: fixed
CPU: 1,2,8,32 (default=1)
DISK: fake
JOUR:int
CL: 1,2,4,8 (default=1)
OSS:1,2,4 (default=1)
NET: IB
OSTN:1,2,4 (default=1)
TH: 1,2,4,8 (default=1)
F: debug
TEST:
*) bulk size: rszlo=rszhi=N (1,4,64,1024)
*) TH is specified through: thrlo=1, thrhi=8 (thread count, 1,2,4,8)
*) each OST is supposed to be configured on a separate disk.
*) the amount of objects is: nobjlo=nobjhi=[1;TH]
i.e. test only cases when all the threads work on the same file and
when all of them work on a separate file.
[4 bulks; common of separate dir]=8 tests

Test matrix(TESTxTHxCLxCPUxNETxOSSxOSTN):
1. Multi-thread test.
Run TESTs on CL=1 with different amount of threads. TESTxTH=8x4=32 tests
2. Multi-client test
2.1. Let's check how clients scale vs. threads per client (TH=1).
2.2. Let's check how the system scale with many clients and threads  
(TH=8).
Note: to be more demonstrative, the maximum amount of threads could be  
taken
<8, if TH=8 reaches the maximum network throughput with small amount  
of clients.
[CL>1;TH=1,8]. TESTxCLxTH=8x3x2=48 tests.
3. Network test
Having IB results in hand after (1,2) and these results from NETT2, we  
already see how
osc+ost+ptlrpc+obdfilter changes the behavior. Thus, there is no  
reason to repeat them
for GiGe, it seems.
4.CPU test
Note: lnet fixes from Liang to be applied here.
Run TESTs on different amount of CPU.
It is mostly interesting to look at large amount of threads, as we are
going to benefit from handling them in parallel.
At the same time, if some HW (network) limit is reached, the result  
will not be
very demonstrative, so test with 1 small & 1 large bulk size only:[1k; 
1024K]:
[CL=8,TH=1,2,4,8]. TESTxCLxTHxCPU=4x1x4x(4-1)=48.
5. OSTN test.
The same OSC, network, CPU, disk, just check how OST stack (see 1,2
tests) is scalable.
5.1. Let's check how N threads per 1 OST vs. 1 thread per N OST scales  
(CL=OSTN).
5.2. Let's check how the system scale with many clients and threads  
(CL=8)
Note: to be more demonstrative, the maximum amount of threads could be  
taken
<8, if TH=8 reaches the maximum network throughput with small amount  
of clients.
It seems enough to look at 1 small & 1 large bulk only: [1,1024K]
[CL=OSTN,8;TH=1,8]. TESTxCLxTHxOSTN=4x2x2x2=32 tests
6. OSS test.
6.1. Let's check how 1 thread per N OST vs. 1 thread per N OSS scales  
(CL=OSS).
6.2. Let's check how the system scale with many clients and threads  
(CL=8)
Note: to be more demonstrative, the maximum amount of threads could be  
taken
<8, if TH=8 reaches the maximum network throughput with small amount  
of clients.
It seems enough to look@1 small & 1 large bulk only: [1,1024K]
[CL=OSS,8;TH=1,8]. TESTxCLxTHxOSTN=4x2x2x2=32 tests

Total:192 tests

*** OSTT3. Client-OST test ***
lustre-iokit: ior-survey.

The test results are to be compared with OSTT2 results to get the  
overhead
for Lustre Client: client stack, distributed locking, etc.

RAM: fixed
CPU: 1,2,8,32 (default=1)
DISK: fake
JOUR:int
CL: 1,2,4,8 (default=1)
OSS:1,2,4 (default=1)
NET: IB
OSTN:1,2,4 (default=1)
TH: 1,2,4,8 (default=1)
F: debug
TEST:
*) CL is specified through $clients_hi
*) TH is specified through $tasks_per_client_hi
*) bulk is specified through  rsize_lo/hi (1,4,64,1028K)
*) file_per_task=[0;1]
i.e. test only cases when all the threads work on the same file and
when all of them work on a separate file.
[4 bulks; common of separate dir]=8 tests

Test matrix(TESTxTHxCLxCPU): absolutely the same as for OSTT2.

NETT3. MD: (not ready)
MDST1. Isolated MDS (not ready)
MDST2. Remote MDS (not ready)
This set of tests need to be implemented in a utility similar to  
obdfilter-survey
but for MDS testing.

MDST3. Simple Client-MDS operation tests

1. create,mknod,mkdir (symlink, link??)
RAM: fixed
CPU: 1,2,8,32 (default=1)
DISK(MDS): tmpfs, raid, regular (default=tmpfs)
DISK(OST): tmpfs
JOUR: int,ext,ram (default=int)
CL: 1,2,4,8 (default=1)
OSS:1,2,4 (default=1)
NET: IB
OSTN:1
TH: 1,2,4,8 (default=1)
F: debug
TEST: it will be probably mdsrate/mdsrate-create-small.sh, but it  
needs to be
fixed to support all of these operations, not only create. If so:
*) TH could be specified through THREADS_PER_CLIENT=[1,2,4,8]
*) CL is specified through CLIENTS  or NODES_TO_USE.
*) NOSINGLE should be provided
*) add --dirnum option to COMMAND
*) DIRNUM=[1,TH*CL], so we test a case when all the threads work in the
same dir and when each works in a separate one.
*) nfiles is files-per-dir * DIRNUM
[common or separate dir]=2tests;

Note: we should probably limit the amount of files in 1 directory with  
2M,
otherwise the performance will definitely downgrade.

Test matrix(TESTxTHxCLxCPUxNETxOSS):
1. Multi-thread test.
Run TESTs on CL=1 with different amount of threads. TESTxTH=2x4-1=7  
tests
(not 8 as if TH=1, DIRNUM=1, and this is already covered).
2. Multi-client test
2.1. Let's check how clients scale vs. threads per client (TH=1).
2.2. Let's check how the system scale with many clients and threads  
(TH=8).
Note: to be more demonstrative, the maximum amount of threads could be  
taken
<8, if TH=8 reaches the maximum network throughput with small amount  
of clients.
[CL>1;TH=1,8]. TESTxCLxTH=2x3x2=12 tests.
3. Striped test.
2.1. Let's check how multi-client system scales (TH=1).
2.2. Let's check how large load system scales (TH=8)
Test (only) create with different stripeness.  
TESTxCLxTHxOSS=[2x4x2-1]x2=30
4. Network test
Having IB results in hand after (1,2,3) and these results from NETT1,  
we already see
how mdc+mdt-stack+ptlrpc changes the behavior. There is no reason to  
repeat them
for GiGe, it seems.
5. DISK test.
Unlink the OST testing, we do not have echo-md client (MDTT1), thus we  
have not checked
how different disks impact the performance, so we need to check it here.
Limit this test with only couple of operations: create, mknod.
As different disks are of completely different nature we need to  
repeat most of (1,2) here
[TH=1,8]: TESTxCLxTHxDISK=(2x4x2-1)x2=30
6. JOURNAL test.
Repeat (5) for different journals, but limit the test with raid-disk  
only. TESTxCLxTHxDISKxJOUR=(2x4x2-1)x1x2=30
7.CPU test
Note: lnet fixes from Liang to be applied here.
Run TESTs on different amount of CPU.
Limit this test with only couple of operations: create, mknod.
It is mostly interesting to look at large amount of threads, as we are
going to benefit from handling them in parallel, so run it for CL=max
only: [CL=8,TH=1,2,4,8]. TESTxCLxTHxCPU=2x1x4x(4-1)=24

Total: 19 tests for mkdir, 103 for mknod, 133 for create.

2. lookup (mdsrate-lookup-1dir.sh => mdsrate-lookup.sh)
RAM: fixed
CPU: 1,2,8,32 (default=1)
DISK: tmpfs
JOUR: int
CL: 1,2,4,8 (default=1)
OSS:1
NET: GiGe,IB (default=IB)
OSTN:1
TH: 1,2,4,8 (default=1)
F: debug
TEST: it will be probably better to work out mdsrate-lookup-1dir.sh,  
which
could work in several directories in parallel.
*) TH could be specified through THREADS_PER_CLIENT=[1,2,4,8]
   (to be added into the script)
*) CL is an amount of nodes specified in CLIENTS or NODES_TO_USE.
*) NOSINGLE should be provided
*) add --dirnum option to COMMAND
*) DIRNUM=[1,TH*CL], so we test a case when all the threads work in the
same dir and when each works in a separate one.
*) nfiles is files-per-dir * DIRNUM
*) add READDIR_ORDER to test both random and readdir order lookups.
[common or separate di; readdir,random order]=4 tests.

Q: it seems this test does md_getattr_name(), instead of lookup, thus  
no lock
enqueue is involved.
A: what about to replace it with access(2)??

Test matrix(TESTxTHxCLxCPUxNET): the same as for (1, mknod), but 4 tests
instead of 2: 19x2=38 tests.

3. stat

RAM: fixed
CPU: 1,2,8,32 (default=1)
DISK(MDS): tmpfs, raid, regular (default=tmpfs)
DISK(OST): tmpfs
JOUR: int,ext,ram (default=int)
CL: 1,2,4 (default=1)
OSS:1,2,4 (default=1)
NET: GiGe,IB (default=IB)
OSTN:1
TH: 1,2,4,8 (default=1)
F: debug
TEST: mdsrate/mdsrate-stat-small.sh
*) add THREADS_PER_CLIENT to the script to specify TH
*) CL is specified through CLIENTS  or NODES_TO_USE.
*) NOSINGLE should be provided
*) add --dirnum option to COMMAND
*) DIRNUM=[1,TH*CL], so we test a case when all the threads work in the
same dir and when each works in a separate one.
*) nfiles is files-per-dir * DIRNUM
*) add READDIR_ORDER to test both random and readdir order lookups.
[common or separate dir; readdir,random order]=4 tests.

Q: do we want to test stat(2) with other then tmpfs disk on OST?
what journal should it have if so?

Test matrix(TESTxTHxCLxCPUxNETxDISKxJOUR): the same as for (1, create),
but 4 tests instead of 2: 133x2=266 tests.

4. unlink (mdsrate-create-small.sh, run twice??)
it should be run (and it is run in  mdsrate-create-small.sh) for all
the operations in (1), i.e. create, mkdir, mknod.
The test matrix is the same and the total:
19 tests for mkdir, 103 for mknod, 133 for create.

5. chmod (mdsrate-chmod.sh, new one, fix mdsrate)
The same as (1, mkdir) and the total: 19 tests.

6. utime (mdsrate-utime.sh, new one, fix mdsrate)
The same as (1, mkdir) and the total: 19 tests.

7. chown (mdsrate-chown.sh, new one, fix mdsrate)
The same as (1, create), but skip different DISKs&JOURNALs:
19 + 30 + 24=73 tests.

8. rename (mdsrate-rename.sh, new one, fix mdsrate)
The same as (1, mkdir) and the total: 19 tests.

9. find
Q: despite the fact we currently have a large downgrade with
"find -f type", do we want to have this test in the general test set?

**** MT. Mixed testing. ****

MT1. Create-write test.
RAM: fixed
CPU: 32
DISK(MDS): tmpfs, raid (default=tmpfs)
DISK(OST): raid
JOUR: int
CL: 1,2,4,8 (default=1)
OSS:1 (default=1)
NET: IB
OSTN:1
TH: 1,2,4,8 (default=1)
F: debug
TEST: must be a new one. Each thread creates files in a loop, writes 1  
bulk to each and closes it.
*) it is enough to test with a small bulk only: [1k]
*) [common or separate dir]=2tests;

Test matrix(TESTxTHxCLxCPUxNETxOSS):
1. Multi-thread test.
Run TESTs on CL=1 with different amount of threads. TESTxTH=2x4-1=7  
tests
(not 8 as if TH=1, it is always in 1 dir, and this is already covered).
2. Multi-client test
2.1. Let's check how clients scale vs. threads per client (TH=1).
2.2. Let's check how the system scale with many clients and threads  
(TH=8).
Note: to be more demonstrative, the maximum amount of threads could be  
taken
<8, if TH=8 reaches the maximum network throughput with small amount  
of clients.
[CL>1;TH=1,8]. TESTxCLxTH=2x3x2=12 tests.
3. DISK test.
Check how different disks impact on the performance.
As different disks are of completely different nature we need to  
repeat most of (1,2) here
[TH=1,8]: TESTxCLxTHxDISK=(2x4x2-1)x1=15

Total: 34 tests.

MT2. Create-Readdir test.
RAM: fixed
CPU: 32
DISK(MDS): tmpfs, raid (default=tmpfs)
DISK(OST): raid
JOUR: int
CL: 1,2,4,8 (default=1) (1 extra client does "ls -U")
OSS:1 (default=1)
NET: IB
OSTN:1
TH: 1,2,4,8 (default=1)
F: debug
TEST: must be a new one. Each thread creates files in a loop and  
immediately closes them.
1 thread on another client does "ls -U". It is done in 1 directory.

The test matrix is exactly the same as for MT1. Total: 34 tests.

MT3. ??? Some more tests ????

**** Goal2. Compare HEAD and b1_6 (b1_8) performance. ****

This paragraph describes the testing methodology in the reverse order  
of testing,
i.e. in the top-bottom direction, making sure new LustreFS (HEAD)  
version does
not downgrade comparing with the previous ones (b1_6/b1_8).

Therefore, the first testing cycle includes:
	MT, MDST3, OSTT3, NETT1.
from the above tests. In the case a downgrade is detected, lower layer  
tests are
to be run until the downgrade disappear.

--
Vitaly

[Lustre-devel] LustreFS performance

[Andreas Dilger]

On Mar 02, 2009  20:04 +0300, Vitaly Fertman wrote:
>    RAM: enough to have a tmpfs for MDS;
 
Note that strictly speaking we need to use ldiskfs on a ramdisk, not
tmpfs, because we don't have an fsfilt_tmpfs.

> Q:  which raid?
> A: raid5, as it seems to be the most popular.

I would propose:
- for MDT it needs to be RAID-1+0, because of small, random IO sizes
- for OST it needs to be RAID-6, because of double-failure risk (see
  Lustre Manual "RAID" section for discussion)

> **** Statistics ****
> 
> During all the tests the following is supposed to be running on all  
> the servers:
> 1) vmstat
> 2) iostat, if there is some disk activity.
> smth else?

I would propose either LLNL's LMT or HP's collectl, which both also
collect Lustre stats.  Those both provide more information than the
above, and having the IO/CPU load correlated to Lustre RPC counts is
very useful.

> MDST3
> 
> Q: do we want to test stat(2) with other then tmpfs disk on OST?
> what journal should it have if so?

I would be quite interested in the performance numbers from just
the ramdisk MDT+OST, to see what the upper limit of the protocol
and network are.

> 9. find
> Q: despite the fact we currently have a large downgrade with
> "find -f type", do we want to have this test in the general test set?

Some of that performance loss should have been fixed recently.  We
should continue to test it.

Cheers, Andreas
--
Andreas Dilger
Sr. Staff Engineer, Lustre Group
Sun Microsystems of Canada, Inc.

[Lustre-devel] LustreFS performance

[Oleg Drokin]

Hello!

On Mar 2, 2009, at 3:45 PM, Andreas Dilger wrote:

> On Mar 02, 2009  20:04 +0300, Vitaly Fertman wrote:
>>   RAM: enough to have a tmpfs for MDS;
> Note that strictly speaking we need to use ldiskfs on a ramdisk, not
> tmpfs, because we don't have an fsfilt_tmpfs.

The idea was loop device on tmpfs, I think.

Bye,
     Oleg

[Lustre-devel] LustreFS performance

[Jeff Darcy]

Oleg Drokin wrote:
> On Mar 2, 2009, at 3:45 PM, Andreas Dilger wrote:
>
>   
>> On Mar 02, 2009  20:04 +0300, Vitaly Fertman wrote:
>>     
>>>   RAM: enough to have a tmpfs for MDS;
>>>       
>> Note that strictly speaking we need to use ldiskfs on a ramdisk, not
>> tmpfs, because we don't have an fsfilt_tmpfs.
>>     
>
> The idea was loop device on tmpfs, I think.
>   

FYI, this is exactly what we do with our FabriCache feature - i.e. both 
MDT and OSTs are actually loopback files on tmpfs.  Modulo a few issues 
with preallocated write space eating all storage leaving none for actual 
data, it works rather well producing high performance numbers and giving 
LNDs a good workout.  BTW, the loopback driver does copies and is 
disturbingly single-threaded, which can create a bottleneck.  This can 
be worked around with multiple instances per node, though.

[Lustre-devel] LustreFS performance

[Andreas Dilger]

On Mar 04, 2009  12:28 -0500, Jeff Darcy wrote:
> Oleg Drokin wrote:
>> On Mar 2, 2009, at 3:45 PM, Andreas Dilger wrote:
>>> Note that strictly speaking we need to use ldiskfs on a ramdisk, not
>>> tmpfs, because we don't have an fsfilt_tmpfs.
>>
>> The idea was loop device on tmpfs, I think.
>
> FYI, this is exactly what we do with our FabriCache feature - i.e. both  
> MDT and OSTs are actually loopback files on tmpfs.

The problem with using a loop device instead of a ramdisk is that you now
have 2 layers of indirection - MDS->ldiskfs->loop->tmpfs->RAM instead of
MDS->ldiskfs->RAM.  The drawback (or possibly benefit) is that ramdisks
consume a fixed amount of RAM and are not "sparse" (AFAIK, that may have
changed since I last looked into this).  That said, once a block is written
to by mke2fs or by ldiskfs in the loop->tmpfs case it will also never be
freed again, so you only get some marginal benefit.

> Modulo a few issues  
> with preallocated write space eating all storage leaving none for actual  
> data, it works rather well producing high performance numbers and giving  
> LNDs a good workout.  BTW, the loopback driver does copies and is  
> disturbingly single-threaded, which can create a bottleneck.  This can  
> be worked around with multiple instances per node, though.

Even better, if you have some development skills, would be to implement
(or possibly resurrect) an fsfilt-tmpfs layer.  Since tmpfs isn't going
to be recoverable anyways (I assume you just reformat from scratch when
there is a crash), then you can make all of the transaction handling
as no-ops, and just implement the minimal interfaces needed to work.
That would allow unlinked files to release space from tmpfs, and also
avoid the fixed allocation overhead and journaling of ldiskfs, probably
saving you 5% of RAM (more on the MDS) and a LOT of memcpy() overhead.

Cheers, Andreas
--
Andreas Dilger
Sr. Staff Engineer, Lustre Group
Sun Microsystems of Canada, Inc.

[Lustre-devel] LustreFS performance

[Oleg Drokin]

Hello!

On Mar 5, 2009, at 4:27 PM, Andreas Dilger wrote:
> Even better, if you have some development skills, would be to  
> implement
> (or possibly resurrect) an fsfilt-tmpfs layer.  Since tmpfs isn't  
> going
> to be recoverable anyways (I assume you just reformat from scratch  
> when
> there is a crash), then you can make all of the transaction handling
> as no-ops, and just implement the minimal interfaces needed to work.
> That would allow unlinked files to release space from tmpfs, and also
> avoid the fixed allocation overhead and journaling of ldiskfs,  
> probably
> saving you 5% of RAM (more on the MDS) and a LOT of memcpy() overhead.

This is exactly what I was trying to avoid.
I tried to measure things as if I had an infinitely fast disk only,  
and I
still needed all the journal/blockdevice and other such things to take
the CPU they would normally take.
After all we cannot expect people to actually run real MDSes on tmpfs
unless they have some means to replicate that MDS somewhere else.

Bye,
     Oleg

[Lustre-devel] LustreFS performance

[Andreas Dilger]

On Mar 08, 2009  22:50 -0400, Oleg Drokin wrote:
> On Mar 5, 2009, at 4:27 PM, Andreas Dilger wrote:
>> Even better, if you have some development skills, would be to  
>> implement (or possibly resurrect) an fsfilt-tmpfs layer.  Since
>> tmpfs isn't going to be recoverable anyways (I assume you just
>> reformat from scratch when there is a crash), then you can make
>> all of the transaction handling as no-ops, and just implement
>> the minimal interfaces needed to work.
>>
>> That would allow unlinked files to release space from tmpfs, and also
>> avoid the fixed allocation overhead and journaling of ldiskfs, probably
>> saving you 5% of RAM (more on the MDS) and a LOT of memcpy() overhead.
>
> This is exactly what I was trying to avoid.
> I tried to measure things as if I had an infinitely fast disk only, and I
> still needed all the journal/blockdevice and other such things to take
> the CPU they would normally take.
> After all we cannot expect people to actually run real MDSes on tmpfs
> unless they have some means to replicate that MDS somewhere else.

In fact, it wasn't my proposal for the metadata performance testing
itself, but rather SiCortex are apparently running with RAM-backed
filesystems for some kind of fast cache filesystem (e.g. distributed
shared memory or similar).  I was only proposing their implementation
could be more efficient.

I could imagine that for flash-cache type applications that storing
checkpoints for a short time in a RAM-backed OST pool before migrating
it to persistent storage.

Cheers, Andreas
--
Andreas Dilger
Sr. Staff Engineer, Lustre Group
Sun Microsystems of Canada, Inc.

[Lustre-devel] LustreFS performance

[Mallik Ragampudi]

Vitaly,

This is very comprehensive. Few comments:

1) I think it would be good to start with LLT2 (lustre-iokit: 
ior-survey) and get an out-of-the-box performance
picture/comparison (1.6 and 2.0) from the whole cluster before testing 
the individual layers.
2) Can this plan be extended to include CMD performance testing as well 
? I would expect that most
of your test cases apply for the CMD as well ?
3) I assume the "CPU" parameter in your methodology refers to # of CPUs 
in MDS, right ?
4) I am not sure if we can test 32 cores without hitting other 
bottlenecks beyond 8 coress on the servers.
This will cut down some combinations in the matrix.

Thanks,
Mallik


Vitaly Fertman wrote:
> ****************************************************
>     LustreFS benchmarking methodology.
> ****************************************************
>
> The document aims to describe the benchmarking methodology which helps
> to understand the LustreFS performance and reveal LustreFS bottlenecks in
> different configurations on different hardware, to ensure the next 
> LustreFS
> release does not downgrade comparing with a previous one. In other words:
>     Goal1. Understand the HEAD performance.
>     Goal2. Compare HEAD and b1_6 (b1_8) performance.
>
> To achieve the Goal1, the methodology suggests to test different 
> layers of
> software in the bottom-top direction, i.e. the underlying back-end, 
> the target
> server sitting on this back-end, the network connected to this target 
> and how
> the target performs through this network, etc up to the whole cluster.
> Each next step has only 1 change over the previous one, it is either a 
> new layer
> added or 1 parameter in the configuration is changed (probably another 
> network
> type or another back-end). Comparing the results of each test with the 
> previous
> test, we get the overhead of the added layer or the performance impact of
> changing this parameter.
>
> To achieve the Goal2, the methodology suggests to go in the reverse 
> top-bottom
> direction, i.e. to test some large sub-systems first and, if a 
> downgrade vs. a previous
> LustreFS version is detected, to perform more detailed tests. (This is 
> considered as
> the primary goal of the 2.0 Performance Team).
>
> The document does not cover the way of fixing revealed problems, 
> probably some
> special purpose test needs to be run or oprofile needs to be compiled 
> in -- it is our
> of scope of the document.
>
> Obviously, it is not possible to perform all the thousands of tests in 
> all the configurations,
> running all the special purpose tests, etc, the document tries to 
> prepare:
> 1) all the essential and sufficient tests to see how the system 
> performs in general;
> 2) some minimal amount of essential tests to see how the system scales 
> in different
> conditions.
> Therefore, the plan does not guarantee we will not miss a bottleneck 
> or a bug, it just
> tries to cover maximum possible scenarios in most interesting 
> conditions/environment
> states.
>
> The amount of tests described below is already about 2K, and there 
> will be definitely more,
> and it will take a lot of time to perform all of them and to analyze 
> the results.  So one of
> the major concerns here is how to minimize the amount of test so that 
> we would not miss
> some interesting case and would be able to get all the results within 
> a reasonable amount of
> time. Please keep it in mind while looking at the tests below.
>
> **** Hardware Requirements. ****
>
> The test plan implies that we change only 1 parameter (cpu or disk or 
> network)
> on each step. Thus, the HW requirements are:
>
> -- at least 1 node with:
>   CPU:32;
>   RAM: enough to have a tmpfs for MDS;
>   DISK: raid, regular.
>   NET: both GiGe and IB installed.
> -- besides that: 8 clients, 4 other servers.
> -- the other servers include:
>   DISK: raid, regular.
>   NET: both GiGe and IB installed.
> -- client includes:
> NET: both GiGe and IB installed.
>
> **** Software requirements ****
>
> 1. Short term.
> 1.1 mdsrate
> to be completed to test all the operations listed in MDST3 (see below).
> 1.2 mdsrate-**.sh
> to be fixed/written to run mdsrate properly and test all the 
> operations listed in
> MDST3 (see below).
> 1.3. fake disk
> implement FAIL flag and report 'done' without doing anything in 
> obdfilter to get
> a low-latency disk.
> 1.4. MT.
> add more tests here and implement them.
>
> 2. Long term.
> 2.1. mdtstack-survey
> - an echo client-server is to be written for mds similar to ost.
> - a test script similar to obdfilter-survey.sh is to be written.
>
> **** Different configurations ****
>
> Configuration of Node:
> RAM. Amount of RAM on nodes (?)
> CPU. Count of CPUs on nodes (1..32)
> DISK. Disk type (regular, raid, tmpfs, fake)
> JOUR. Journal type (internal, external, ram)
>
> Q:  which raid?
> A: raid5, as it seems to be the most popular.
>
> fake: to get a low-latency disk, it is preferable to report 'done' 
> without doing anything
> in obdfilter once some FAIL flag is set. It is useful for OST testing, 
> because first of all,
> it does not have a CPU overhead of memcpy of using tmpfs and it lets 
> to test large
> amount of data in contrast to tmpfs. As a drawback, it skips the 
> localfs code paths.
>
> Configuration of Cluster:
> CL. Amount of clients (1,2,4,8)
> OSS. Amount of OSS nodes (1,2,4)
> NET. Network type (GiGe, IB)
> OSTN. Amount of OST per nodes (1,2,4)
>
> Configuration of test.
> TH. Amount of threads per client (1,2,4,8)
> VER. Lustre version (b1_6, HEAD. later b1_8).
> FEAT. Lustre features to turn off (COS, SA, RA, debug messages)
> TEST. Specific test parameters.
>
> **** Testing ****
> Low Layers Testing (LLT)
> LLT1. Raw disk (lustre-iokit:sgpdd-survey)
> LLT2. Local filesystem (lustre-iokit: ior-survey, is fs mounted 
> synchronously?)
>
> Network Testing (NETT).
> NETT1. lnet: lnetself test.
> NETT2. OBD: lustre-iokit: (obdfilter-survey,     
> echo_client-osc-..-net-..-ost-echo_server)
> NETT3. MD: (not ready)
>
> OST Testing (OSTT).
> OSTT1. Isolated OST (lustre-iokit: obdfilter-survey,     
> echo_client-obdfilter-..-disk)
> OSTT2. Remote OST (lustre-iokit: obdfilter-survey,    
> echo_client-osc-..-ost-obdfilter-..-disk)
> OSTT3. Client-OST IO (lustre-iokit: ost-survey, client-ost-disk).
>
> MDS Testing (MDST).
> MDST1. Isolated MDS test (not ready)
> MDST2. Remote MDS test (not ready)
> MDST3. Simple Client-MDS operation test
>
> Mixed testing (MT) (not ready)
>
> **** Statistics ****
>
> During all the tests the following is supposed to be running on all 
> the servers:
> 1) vmstat
> 2) iostat, if there is some disk activity.
> smth else?
>
> *** Goal1. Understand the HEAD performance. ***
>
> The Goal1 describes the testing methodology in the bottom-top direction,
> from the lower layers (disk) to the complete Lustre cluster.
>
> LLT1. Raw disk (lustre-iokit:sgpdd-survey)
> RAM: fixed
> CPU: 1
> DISK: regular,raid,tmpfs (default=raid)
> JOUR:-
> CL: 1
> OSS:1
> NET: -
> OSTN:-
> TH: 1,2,4,8 (default=1)
> F: debug
> TEST:
> *)bulk size is specified as rszlo/rszhi=[1,4,64,1024K]
> *)TH is specified as thrlo/thrhi=[1,2,4,8]
> *)the amount of objects to work on in parallel: crglo=crghi=[1;TH]
> i.e. test only cases when all the threads work on the same file and
> when all of them work on a separate file.
> [bulk;separate or commin dir]=8 tests;
>
> Test matrix(TESTxTHxDISK):
> Run TESTs with different amount of threads for each DISK.
> TESTxTHxDISK=(8x4 - 1)x3=93 tests.
> "-1" because TH=1 is already covered.
>
> Total:93 tests.
>
> *** NETT1. lnetself test.***
>
> RAM: fixed
> CPU: 1,2,8,32 (default=1)
> DISK: -
> JOUR:-
> CL: 1,2,4,8 (default=1)
> OSS:1
> NET: GiGe, IB (default=IB)
> OSTN:1
> TH: 1,2,4,8 (default=1)
> F: debug
> TEST:
> *) test type: PING,READ,WRITE tests
> *) bulk size for READ/WRITE: 1k,4k,64k,1M
> [1 ping + 4 reads + 4 writes] = 9 tests
>
> Test matrix (TESTxCLxTHxNETxCPU):
> 1. Multi-thread test.
> Run TESTs on CL=1 with different amount of threads.
> TESTxTH=[1+4+4]x4=36 tests.
> 2. Multi-client test
> 2.1. Let's check how clients scale vs. threads per client (TH=1).
> 2.2. Let's check how the system scale with many clients and threads 
> (TH=8).
> Note: to be more demonstrative, the maximum amount of threads could be 
> taken
> <8, if TH=8 reaches the maximum network throughput with small amount 
> of clients.
> [CL>1;TH=1,8]. TESTxCLxTH=9x3x2=54 tests.
> 3. Network test
> As the nature of IB is different from GiGe, we need to repeat all the 
> tests
> from (1,2) here. 36+54=90 tests.
> 4. CPU test
> Note: lnet fixes from Liang to be applied here.
> Run TESTs on different amount of CPU.
> It is mostly interesting to look at large amount of threads, as we are
> going to benefit from handling them in parallel.
> At the same time, if some HW (network) limit is reached, the result 
> will not be
> very demonstrative, so test with 1 small & 1 large bulk size 
> only:[1k;1024K]:
> [CL=8,TH=1,2,4,8]. TESTxCLxTHxCPU=5x1x4x(4-1)=60.
>
> Total: 240 tests.
>
> *** NETT2. OBD performance ***
> lustre-iokit: obdfilter-survey, case=network.
>     
> The results of this tests are to be compared with lnet results to get
> the osc+ost+ptlrpc overhead.
>
> RAM: fixed
> CPU: 1
> DISK: -
> JOUR:-
> CL: 1,2,4,8 (default=1)
> OSS:1
> NET: IB
> OSTN:1
> TH: 1,2,4,8 (default=1)
> F: debug
> TEST:
> *) bulk size: rszlo=rszhi=N (1,4,64,1024)
> *) TH is specified through: thrlo=1, thrhi=8 (thread count, 1,2,4,8)
> *) the amount of objects is: nobjlo=nobjhi=[1;TH]
> i.e. test only cases when all the threads work on the same file and
> when all of them work on a separate file.
> [4 bulks; common or separate dir]=8 tests
>
> Test matrix(TESTxTHxCLxNET):
> 1. Multi-thread test.
> Run TESTs on CL=1 with different amount of threads. TESTxTH=8x4=32 tests
> 2. Multi-client test
> 2.1. Let's check how clients scale vs. threads per client (TH=1).
> 2.2. Let's check how the system scale with many clients and threads 
> (TH=8).
> Note: to be more demonstrative, the maximum amount of threads should 
> be taken
> <8, if TH=8 reaches the maximum network throughput with small amount 
> of clients.
> [CL>1;TH=1,8]. TESTxCLxTH=8x3x2=48 tests.
> 3. Network test.
> Having IB results in hand after (1,2) and these results from NETT1, we 
> already see how
> osc+ost+ptlrpc changes the behavior. There is no reason to repeat them 
> for GiGe, it seems.
> 4.CPU test
> Note: lnet fixes from Liang to be applied here.
> Run TESTs on different amount of CPU.
> It is mostly interesting to look at large amount of threads, as we are
> going to benefit from handling them in parallel.
> At the same time, if some HW (network) limit is reached, the result 
> will not be
> very demonstrative, so test with 1 small & 1 large bulk size 
> only:[1k;1024K]:
> [CL=8,TH=1,2,4,8]. TESTxCLxTHxCPU=4x1x4x(4-1)=48.
>
> Total: 128 tests.
>
> *** OSTT1. Isolated OST ***
> lustre-iokit: obdfilter-survey, case=disk
>
> The results of this tests are to be compared with LLT results to get 
> the OST
> stack overhead.
>
> RAM: fixed
> CPU: 1,2,8,32 (default=1)
> DISK: regular, raid, fake (default=fake)
> JOUR: int, ext, ram, (default=int)
> CL: 1
> OSS:1
> NET: -
> OSTN:1,2,4 (default=1)
> TH: 1,2,4,8 (default=1)
> F: debug
> TEST:
> *) bulk size: rszlo=rszhi=N (1,4,64,1024K)
> *) TH is specified through: thrlo=1, thrhi=8 (1,2,4,8)
> *) each OST is supposed to be configured on a separate disk.
> *) the amount of objects is: nobjlo=nobjhi=[1;TH]
> i.e. test only cases when all the threads work on the same file and
> when all of them work on a separate file.
> [4 bulks; common of separate dir]=8 tests
>
> Test matrix(TESTxTHxOSTNxDISKxCPU):
> 1. Multi-thread test.
> Run TESTs on OSTN=1 with different amount of threads. TESTxTH=8x4=32 
> tests
> 2. Multi-OST test
> 2.1. Let's check how OSTs vs. threads per OST scale (TH=OSTN).
> 2.2. Let's check how the system scale with many OSTs and threads 
> (TH=8*OSTN).
> [OSTN>1;TH=OSTN,8*OSTN]. TESTxOSTNxTH=8x2x2=32 tests.
> 3. DISK test
> As other disks are completely different, so lets repeat most of the 
> (1,2) for 2 others:
> [TH=OSTN;8*OSTN]: TESTxOSTNxTHxDISK=8x3x2x2=96
> 4. JOURNAL test.
> Limit the tests with only raid-disk.
> Limit the test with only 1 large and 1 small bulk:[1,1024K].
> TESTxOSTNxTHxJOUR: 4x3x2x2=48
> 5. CPU test
> Note: lnet fixes from Liang to be applied here.
> Run TESTs on different amount of CPU. It is better to perform it on a 
> fast
> backend (DISK=fake) to see how CPU really matters.
> It is mostly interesting to look at large amount of threads, as we are 
> going
> to benefit from handling them in parallel.
> Also, run with a small & a large bulk only:[1,1024K]
> [OSTN=4,TH=1,2,4,8]: TESTxOSTNxTHxCPU=4x1x4x3=48
>
> Total: 256 tests.
>
> *** OSTT2. Real OST test ***
> lustre-iokit: obdfilter-survey, case=netdisk
>
> This test is a composition of OBD performance and Isolated OST tests,
> so its results are to be compared with NETT2 & OSTT1 results.
>
> RAM: fixed
> CPU: 1,2,8,32 (default=1)
> DISK: fake
> JOUR:int
> CL: 1,2,4,8 (default=1)
> OSS:1,2,4 (default=1)
> NET: IB
> OSTN:1,2,4 (default=1)
> TH: 1,2,4,8 (default=1)
> F: debug
> TEST:
> *) bulk size: rszlo=rszhi=N (1,4,64,1024)
> *) TH is specified through: thrlo=1, thrhi=8 (thread count, 1,2,4,8)
> *) each OST is supposed to be configured on a separate disk.
> *) the amount of objects is: nobjlo=nobjhi=[1;TH]
> i.e. test only cases when all the threads work on the same file and
> when all of them work on a separate file.
> [4 bulks; common of separate dir]=8 tests
>
> Test matrix(TESTxTHxCLxCPUxNETxOSSxOSTN):
> 1. Multi-thread test.
> Run TESTs on CL=1 with different amount of threads. TESTxTH=8x4=32 tests
> 2. Multi-client test
> 2.1. Let's check how clients scale vs. threads per client (TH=1).
> 2.2. Let's check how the system scale with many clients and threads 
> (TH=8).
> Note: to be more demonstrative, the maximum amount of threads could be 
> taken
> <8, if TH=8 reaches the maximum network throughput with small amount 
> of clients.
> [CL>1;TH=1,8]. TESTxCLxTH=8x3x2=48 tests.
> 3. Network test
> Having IB results in hand after (1,2) and these results from NETT2, we 
> already see how
> osc+ost+ptlrpc+obdfilter changes the behavior. Thus, there is no 
> reason to repeat them
> for GiGe, it seems.
> 4.CPU test
> Note: lnet fixes from Liang to be applied here.
> Run TESTs on different amount of CPU.
> It is mostly interesting to look at large amount of threads, as we are
> going to benefit from handling them in parallel.
> At the same time, if some HW (network) limit is reached, the result 
> will not be
> very demonstrative, so test with 1 small & 1 large bulk size 
> only:[1k;1024K]:
> [CL=8,TH=1,2,4,8]. TESTxCLxTHxCPU=4x1x4x(4-1)=48.
> 5. OSTN test.
> The same OSC, network, CPU, disk, just check how OST stack (see 1,2
> tests) is scalable.
> 5.1. Let's check how N threads per 1 OST vs. 1 thread per N OST scales 
> (CL=OSTN).
> 5.2. Let's check how the system scale with many clients and threads 
> (CL=8)
> Note: to be more demonstrative, the maximum amount of threads could be 
> taken
> <8, if TH=8 reaches the maximum network throughput with small amount 
> of clients.
> It seems enough to look at 1 small & 1 large bulk only: [1,1024K]
> [CL=OSTN,8;TH=1,8]. TESTxCLxTHxOSTN=4x2x2x2=32 tests
> 6. OSS test.
> 6.1. Let's check how 1 thread per N OST vs. 1 thread per N OSS scales 
> (CL=OSS).
> 6.2. Let's check how the system scale with many clients and threads 
> (CL=8)
> Note: to be more demonstrative, the maximum amount of threads could be 
> taken
> <8, if TH=8 reaches the maximum network throughput with small amount 
> of clients.
> It seems enough to look at 1 small & 1 large bulk only: [1,1024K]
> [CL=OSS,8;TH=1,8]. TESTxCLxTHxOSTN=4x2x2x2=32 tests
>
> Total:192 tests
>
> *** OSTT3. Client-OST test ***
> lustre-iokit: ior-survey.
>
> The test results are to be compared with OSTT2 results to get the 
> overhead
> for Lustre Client: client stack, distributed locking, etc.
>
> RAM: fixed
> CPU: 1,2,8,32 (default=1)
> DISK: fake
> JOUR:int
> CL: 1,2,4,8 (default=1)
> OSS:1,2,4 (default=1)
> NET: IB
> OSTN:1,2,4 (default=1)
> TH: 1,2,4,8 (default=1)
> F: debug
> TEST:
> *) CL is specified through $clients_hi
> *) TH is specified through $tasks_per_client_hi
> *) bulk is specified through  rsize_lo/hi (1,4,64,1028K)
> *) file_per_task=[0;1]
> i.e. test only cases when all the threads work on the same file and
> when all of them work on a separate file.
> [4 bulks; common of separate dir]=8 tests
>
> Test matrix(TESTxTHxCLxCPU): absolutely the same as for OSTT2.
>
> NETT3. MD: (not ready)
> MDST1. Isolated MDS (not ready)
> MDST2. Remote MDS (not ready)
> This set of tests need to be implemented in a utility similar to 
> obdfilter-survey
> but for MDS testing.
>
> MDST3. Simple Client-MDS operation tests
>
> 1. create,mknod,mkdir (symlink, link??)
> RAM: fixed
> CPU: 1,2,8,32 (default=1)
> DISK(MDS): tmpfs, raid, regular (default=tmpfs)
> DISK(OST): tmpfs
> JOUR: int,ext,ram (default=int)
> CL: 1,2,4,8 (default=1)
> OSS:1,2,4 (default=1)
> NET: IB
> OSTN:1
> TH: 1,2,4,8 (default=1)
> F: debug
> TEST: it will be probably mdsrate/mdsrate-create-small.sh, but it 
> needs to be
> fixed to support all of these operations, not only create. If so:
> *) TH could be specified through THREADS_PER_CLIENT=[1,2,4,8]
> *) CL is specified through CLIENTS  or NODES_TO_USE.
> *) NOSINGLE should be provided
> *) add --dirnum option to COMMAND
> *) DIRNUM=[1,TH*CL], so we test a case when all the threads work in the
> same dir and when each works in a separate one.
> *) nfiles is files-per-dir * DIRNUM
> [common or separate dir]=2tests;
>
> Note: we should probably limit the amount of files in 1 directory with 
> 2M,
> otherwise the performance will definitely downgrade.
>
> Test matrix(TESTxTHxCLxCPUxNETxOSS):
> 1. Multi-thread test.
> Run TESTs on CL=1 with different amount of threads. TESTxTH=2x4-1=7 tests
> (not 8 as if TH=1, DIRNUM=1, and this is already covered).
> 2. Multi-client test
> 2.1. Let's check how clients scale vs. threads per client (TH=1).
> 2.2. Let's check how the system scale with many clients and threads 
> (TH=8).
> Note: to be more demonstrative, the maximum amount of threads could be 
> taken
> <8, if TH=8 reaches the maximum network throughput with small amount 
> of clients.
> [CL>1;TH=1,8]. TESTxCLxTH=2x3x2=12 tests.
> 3. Striped test.
> 2.1. Let's check how multi-client system scales (TH=1).
> 2.2. Let's check how large load system scales (TH=8)
> Test (only) create with different stripeness. 
> TESTxCLxTHxOSS=[2x4x2-1]x2=30
> 4. Network test
> Having IB results in hand after (1,2,3) and these results from NETT1, 
> we already see
> how mdc+mdt-stack+ptlrpc changes the behavior. There is no reason to 
> repeat them
> for GiGe, it seems.
> 5. DISK test.
> Unlink the OST testing, we do not have echo-md client (MDTT1), thus we 
> have not checked
> how different disks impact the performance, so we need to check it here.
> Limit this test with only couple of operations: create, mknod.
> As different disks are of completely different nature we need to 
> repeat most of (1,2) here
> [TH=1,8]: TESTxCLxTHxDISK=(2x4x2-1)x2=30
> 6. JOURNAL test.
> Repeat (5) for different journals, but limit the test with raid-disk 
> only. TESTxCLxTHxDISKxJOUR=(2x4x2-1)x1x2=30
> 7.CPU test
> Note: lnet fixes from Liang to be applied here.
> Run TESTs on different amount of CPU.
> Limit this test with only couple of operations: create, mknod.
> It is mostly interesting to look at large amount of threads, as we are
> going to benefit from handling them in parallel, so run it for CL=max
> only: [CL=8,TH=1,2,4,8]. TESTxCLxTHxCPU=2x1x4x(4-1)=24
>
> Total: 19 tests for mkdir, 103 for mknod, 133 for create.
>
> 2. lookup (mdsrate-lookup-1dir.sh => mdsrate-lookup.sh)
> RAM: fixed
> CPU: 1,2,8,32 (default=1)
> DISK: tmpfs
> JOUR: int
> CL: 1,2,4,8 (default=1)
> OSS:1
> NET: GiGe,IB (default=IB)
> OSTN:1
> TH: 1,2,4,8 (default=1)
> F: debug
> TEST: it will be probably better to work out mdsrate-lookup-1dir.sh, 
> which
> could work in several directories in parallel.
> *) TH could be specified through THREADS_PER_CLIENT=[1,2,4,8]
>   (to be added into the script)
> *) CL is an amount of nodes specified in CLIENTS or NODES_TO_USE.
> *) NOSINGLE should be provided
> *) add --dirnum option to COMMAND
> *) DIRNUM=[1,TH*CL], so we test a case when all the threads work in the
> same dir and when each works in a separate one.
> *) nfiles is files-per-dir * DIRNUM
> *) add READDIR_ORDER to test both random and readdir order lookups.
> [common or separate di; readdir,random order]=4 tests.
>
> Q: it seems this test does md_getattr_name(), instead of lookup, thus 
> no lock
> enqueue is involved.
> A: what about to replace it with access(2)??
>
> Test matrix(TESTxTHxCLxCPUxNET): the same as for (1, mknod), but 4 tests
> instead of 2: 19x2=38 tests.
>
> 3. stat
>
> RAM: fixed
> CPU: 1,2,8,32 (default=1)
> DISK(MDS): tmpfs, raid, regular (default=tmpfs)
> DISK(OST): tmpfs
> JOUR: int,ext,ram (default=int)
> CL: 1,2,4 (default=1)
> OSS:1,2,4 (default=1)
> NET: GiGe,IB (default=IB)
> OSTN:1
> TH: 1,2,4,8 (default=1)
> F: debug
> TEST: mdsrate/mdsrate-stat-small.sh
> *) add THREADS_PER_CLIENT to the script to specify TH
> *) CL is specified through CLIENTS  or NODES_TO_USE.
> *) NOSINGLE should be provided
> *) add --dirnum option to COMMAND
> *) DIRNUM=[1,TH*CL], so we test a case when all the threads work in the
> same dir and when each works in a separate one.
> *) nfiles is files-per-dir * DIRNUM
> *) add READDIR_ORDER to test both random and readdir order lookups.
> [common or separate dir; readdir,random order]=4 tests.
>
> Q: do we want to test stat(2) with other then tmpfs disk on OST?
> what journal should it have if so?
>
> Test matrix(TESTxTHxCLxCPUxNETxDISKxJOUR): the same as for (1, create),
> but 4 tests instead of 2: 133x2=266 tests.
>
> 4. unlink (mdsrate-create-small.sh, run twice??)
> it should be run (and it is run in  mdsrate-create-small.sh) for all
> the operations in (1), i.e. create, mkdir, mknod.
> The test matrix is the same and the total:
> 19 tests for mkdir, 103 for mknod, 133 for create.
>
> 5. chmod (mdsrate-chmod.sh, new one, fix mdsrate)
> The same as (1, mkdir) and the total: 19 tests.
>
> 6. utime (mdsrate-utime.sh, new one, fix mdsrate)
> The same as (1, mkdir) and the total: 19 tests.
>
> 7. chown (mdsrate-chown.sh, new one, fix mdsrate)
> The same as (1, create), but skip different DISKs&JOURNALs:
> 19 + 30 + 24=73 tests.
>
> 8. rename (mdsrate-rename.sh, new one, fix mdsrate)
> The same as (1, mkdir) and the total: 19 tests.
>
> 9. find
> Q: despite the fact we currently have a large downgrade with
> "find -f type", do we want to have this test in the general test set?
>
> **** MT. Mixed testing. ****
>
> MT1. Create-write test.
> RAM: fixed
> CPU: 32
> DISK(MDS): tmpfs, raid (default=tmpfs)
> DISK(OST): raid
> JOUR: int
> CL: 1,2,4,8 (default=1)
> OSS:1 (default=1)
> NET: IB
> OSTN:1
> TH: 1,2,4,8 (default=1)
> F: debug
> TEST: must be a new one. Each thread creates files in a loop, writes 1 
> bulk to each and closes it.
> *) it is enough to test with a small bulk only: [1k]
> *) [common or separate dir]=2tests;
>
> Test matrix(TESTxTHxCLxCPUxNETxOSS):
> 1. Multi-thread test.
> Run TESTs on CL=1 with different amount of threads. TESTxTH=2x4-1=7 tests
> (not 8 as if TH=1, it is always in 1 dir, and this is already covered).
> 2. Multi-client test
> 2.1. Let's check how clients scale vs. threads per client (TH=1).
> 2.2. Let's check how the system scale with many clients and threads 
> (TH=8).
> Note: to be more demonstrative, the maximum amount of threads could be 
> taken
> <8, if TH=8 reaches the maximum network throughput with small amount 
> of clients.
> [CL>1;TH=1,8]. TESTxCLxTH=2x3x2=12 tests.
> 3. DISK test.
> Check how different disks impact on the performance.
> As different disks are of completely different nature we need to 
> repeat most of (1,2) here
> [TH=1,8]: TESTxCLxTHxDISK=(2x4x2-1)x1=15
>
> Total: 34 tests.
>
> MT2. Create-Readdir test.
> RAM: fixed
> CPU: 32
> DISK(MDS): tmpfs, raid (default=tmpfs)
> DISK(OST): raid
> JOUR: int
> CL: 1,2,4,8 (default=1) (1 extra client does "ls -U")
> OSS:1 (default=1)
> NET: IB
> OSTN:1
> TH: 1,2,4,8 (default=1)
> F: debug
> TEST: must be a new one. Each thread creates files in a loop and 
> immediately closes them.
> 1 thread on another client does "ls -U". It is done in 1 directory.
>
> The test matrix is exactly the same as for MT1. Total: 34 tests.
>
> MT3. ??? Some more tests ????
>
> **** Goal2. Compare HEAD and b1_6 (b1_8) performance. ****
>
> This paragraph describes the testing methodology in the reverse order 
> of testing,
> i.e. in the top-bottom direction, making sure new LustreFS (HEAD) 
> version does
> not downgrade comparing with the previous ones (b1_6/b1_8).
>
> Therefore, the first testing cycle includes:
>     MT, MDST3, OSTT3, NETT1.
> from the above tests. In the case a downgrade is detected, lower layer 
> tests are
> to be run until the downgrade disappear.
>
> -- 
> Vitaly


-- 
Mallik Ragampudi         (877)860-5044  Lustre Engineering
x52907 Sun Microsystems 
Mallikarjunarao.Ragampudi at sun.com 

[Lustre-devel] LustreFS performance

[Nicholas Henke]

Andreas Dilger wrote:
> On Mar 02, 2009  20:04 +0300, Vitaly Fertman wrote:
>>    RAM: enough to have a tmpfs for MDS;

>> **** Statistics ****
>>
>> During all the tests the following is supposed to be running on all  
>> the servers:
>> 1) vmstat
>> 2) iostat, if there is some disk activity.
>> smth else?
> 
> I would propose either LLNL's LMT or HP's collectl, which both also
> collect Lustre stats.  Those both provide more information than the
> above, and having the IO/CPU load correlated to Lustre RPC counts is
> very useful.

It would be great if we could standardize on a set of tools for performance 
issues. I've got to think a set of tools like this would make it easier for 
customer & partners to gather the correct data the first time.

Cray has been using lstats, a package of scripts we got from Sun a while back. 
We've added things like AT timeout and sar per-cpu usage to it (see bug 18574 
att 22140 for complete set of scripts).

I'm all for using collectl, but I think the requirements and setup for LMT makes 
  it a tough sell. Does Sun have a set of customizations for collectl or does 
the standard collectl collect enough information?

Nic

[Lustre-devel] LustreFS performance

[Mark Seger]

>>> **** Statistics ****
>>>
>>> During all the tests the following is supposed to be running on all  
>>> the servers:
>>> 1) vmstat
>>> 2) iostat, if there is some disk activity.
>>> smth else?
>>>       
>> I would propose either LLNL's LMT or HP's collectl, which both also
>> collect Lustre stats.  Those both provide more information than the
>> above, and having the IO/CPU load correlated to Lustre RPC counts is
>> very useful.
>>     
>
> It would be great if we could standardize on a set of tools for performance 
> issues. I've got to think a set of tools like this would make it easier for 
> customer & partners to gather the correct data the first time.
>
> Cray has been using lstats, a package of scripts we got from Sun a while back. 
> We've added things like AT timeout and sar per-cpu usage to it (see bug 18574 
> att 22140 for complete set of scripts).
>
> I'm all for using collectl, but I think the requirements and setup for LMT makes 
>   it a tough sell. Does Sun have a set of customizations for collectl or does 
> the standard collectl collect enough information?
>   
My goal when I wrote collectl was to provide one-stop shopping for as 
much system performance data as seemed relevant and view lustre as only 
one of many data sources.  To that end, if you do a merge of all the 
data collected by the *stat utilities, sar, perfquery (for IB), many of 
the lustre stats (but not all) and maybe a few others you'll get closer 
to understanding what collectl can collect.  On the output side you can 
pick and choose what to display - when used interactively only those 
data elements are collected but when run as a daemon you can collect 
them all and replay the data as ofter as you like looking at different 
slices.

As for LMT I haven't played with it as my interests are in dealing with 
all data.  However, as an exercise left to the reader, there are a 
number of switches for changing collectl's display as well as --home 
which moves the cursor the terminal's home position before displaying 
the output, giving a display similar to the feel of top.  If you want to 
display what's happening to lustre and your disks, cpu, etc all at the 
same time on a refreshing display, --top is definitely the way to go.

And finally, if you want something totally different and are feeling 
creative, just write your own print routines in perl and tell collectl 
to use them with the --export switch.

-mark

[Lustre-devel] LustreFS performance

[Vitaly Fertman]

On Mar 10, 2009, at 2:55 PM, Mallik Ragampudi wrote:

> Vitaly,
>
> This is very comprehensive. Few comments:
>
> 1) I think it would be good to start with LLT2 (lustre-iokit: ior- 
> survey) and get an out-of-the-box performance
> picture/comparison (1.6 and 2.0) from the whole cluster before  
> testing the individual layers.

LLT2 is about underlying local fs on servers, not Lustre.
the overall ior-survey is OSTT3 (it was wrongly mentioned as ost-survey
in the document header, sorry, it must be ior-survey as written
in the detailed section)

> 2) Can this plan be extended to include CMD performance testing as  
> well ? I would expect that most
> of your test cases apply for the CMD as well ?

sure, I will extend it.

> 3) I assume the "CPU" parameter in your methodology refers to # of  
> CPUs in MDS, right ?

to the server which is being tested at the moment, i.e. OST for OST*  
tests,
MDS fro MDS* tests. In the mixed section it refers to MDS indeed.

> 4) I am not sure if we can test 32 cores without hitting other  
> bottlenecks beyond 8 coress on the servers.

if we hit some bottleneck, we will get a problem to solve, what is  
good ;)
however, to see the bottleneck from these results, it is better to run  
MT
tests with different amount of CPUs (the same as for all the CPU  
tests, 1,2,8,32).

> This will cut down some combinations in the matrix.
>
> Thanks,
> Mallik
>

--
Vitaly

[Lustre-devel] LustreFS performance (update)

[Vitaly Fertman]

****************************************************
	LustreFS benchmarking methodology.
****************************************************

The document aims to describe the benchmarking methodology which helps
to understand the LustreFS performance and reveal LustreFS bottlenecks  
in
different configurations on different hardware, to ensure the next  
LustreFS
release does not downgrade comparing with a previous one. In other  
words:
	Goal1. Understand the HEAD performance.
	Goal2. Compare HEAD and b1_6 (b1_8) performance.

To achieve the Goal1, the methodology suggests to test different  
layers of
software in the bottom-top direction, i.e. the underlying back-end,  
the target
server sitting on this back-end, the network connected to this target  
and how
the target performs through this network, etc up to the whole cluster.
Each next step has only 1 change over the previous one, it is either a  
new layer
added or 1 parameter in the configuration is changed (probably another  
network
type or another back-end). Comparing the results of each test with the  
previous
test, we get the overhead of the added layer or the performance impact  
of
changing this parameter.

To achieve the Goal2, the methodology suggests to go in the reverse  
top-bottom
direction, i.e. to test some large sub-systems first and, if a  
downgrade vs. a previous
LustreFS version is detected, to perform more detailed tests. (This is  
considered as
the primary goal of the 2.0 Performance Team).

The document does not cover the way of fixing revealed problems,  
probably some
special purpose test needs to be run or oprofile needs to be compiled  
in -- it is our
of scope of the document.

Obviously, it is not possible to perform all the thousands of tests in  
all the configurations,
running all the special purpose tests, etc, the document tries to  
prepare:
1) all the essential and sufficient tests to see how the system  
performs in general;
2) some minimal amount of essential tests to see how the system scales  
in different
conditions.
Therefore, the plan does not guarantee we will not miss a bottleneck  
or a bug, it just
tries to cover maximum possible scenarios in most interesting  
conditions/environment
states.

The amount of tests described below is already about 2K, and there  
will be definitely more,
and it will take a lot of time to perform all of them and to analyze  
the results.  So one of
the major concerns here is how to minimize the amount of test so that  
we would not miss
some interesting case and would be able to get all the results within  
a reasonable amount of
time. Please keep it in mind while looking at the tests below.

**** Hardware Requirements. ****

The test plan implies that we change only 1 parameter (cpu or disk or  
network)
on each step. The HW requirements are:

-- at least 1 node with:
  CPU:32;
  RAM: enough to have a ramdisk for MDS;
  DISK: enough disks for raid6 or raid1+0 (as this node could be mds  
or ost);
	  an extra disk for external journal;
  NET: both GiGe and IB installed.
-- at least 1 another node includes:
  DISK: enough disks for raid6 or raid1+0 (as this node could be mds  
or ost);
	  an extra disk for external journal;
-- besides that: 8 clients, 3 other servers.
-- the other servers include:
  DISK: raid6
  NET: IB installed.
-- client includes:
NET: both GiGe and IB installed.

**** Software requirements ****

1. Short term.
1.1 mdsrate
to be completed to test all the operations listed in MDST3 (see below).
1.2 mdsrate-**.sh
to be fixed/written to run mdsrate properly and test all the  
operations listed in
MDST3 (see below).
1.3. fake disk
implement FAIL flag and report 'done' without doing anything in  
obdfilter to get
a low-latency disk.
1.4. MT.
add more tests here and implement them.

2. Long term.
2.1. mdtstack-survey
- an echo client-server is to be written for mds similar to ost.
- a test script similar to obdfilter-survey.sh is to be written.

**** Different configurations ****

Configuration of Node:
RAM. Amount of RAM on nodes (?)
CPU. Count of CPUs on nodes (1..32)
DISK. Disk type (raid, ramdisk, fake)
JOUR. Journal type (internal, external, ram)

Q:  which raid?
A: use RAID 1+0 for MDS; RAID6 for OST.

fake: to get a low-latency disk, it is preferable to report 'done'  
without doing anything
in obdfilter once some FAIL flag is set. It is useful for OST testing,  
because first of all,
it does not have a CPU overhead of memcpy of using ramdisk and it lets  
to test large
amount of data in contrast to ramdisk. As a drawback, it skips the  
localfs code paths.

Note: OSS back-end has write through cache; MDS back-end has write- 
back cache.

Configuration of Cluster:
CL. Amount of clients (1,2,4,8)
MDS. Amount of MDS nodes (1,2,4).
OSS. Amount of OSS nodes (1,2,4)
NET. Network type (GiGe, IB)
OSTN. Amount of OST per nodes (1,2,4)

Configuration of test.
TH. Amount of threads per client (1,2,4,8)
VER. Lustre version (b1_6, HEAD. later b1_8).
FEAT. Lustre features to turn off (COS, SA, RA, debug messages)
TEST. Specific test parameters.

**** Testing ****
Low Layers Testing (LLT)
LLT1. Raw disk (lustre-iokit:sgpdd-survey)
LLT2. Local filesystem (lustre-iokit: ior-survey, is fs mounted  
synchronously?)

Network Testing (NETT).
NETT1. lnet: lnetself test.
NETT2. OBD: lustre-iokit: (obdfilter-survey, 	echo_client-osc-..- 
net-..-ost-echo_server)
NETT3. MD: (not ready)

OST Testing (OSTT).
OSTT1. Isolated OST (lustre-iokit: obdfilter-survey, 	echo_client- 
obdfilter-..-disk)
OSTT2. Remote OST (lustre-iokit: obdfilter-survey,	echo_client-osc-..- 
ost-obdfilter-..-disk)
OSTT3. Client-OST IO (lustre-iokit: ior-survey, client-ost-disk).

MDS Testing (MDST).
MDST1. Isolated MDS test (not ready)
MDST2. Remote MDS test (not ready)
MDST3. Simple Client-MDS operation test

Mixed testing (MT) (not ready)

**** Statistics ****

During all the tests the following is supposed to be running on all  
the servers:
1) HP collectl or LLNL's LMT;
2) smth else?

*** Goal1. Understand the HEAD performance. ***

The Goal1 describes the testing methodology in the bottom-top direction,
from the lower layers (disk) to the complete Lustre cluster.

LLT1. Raw disk (lustre-iokit:sgpdd-survey)
RAM: fixed
CPU: 1
DISK: raid,ramdisk,fake (default=raid)
JOUR:-
CL: 1
OSS:1
NET: -
OSTN:-
TH: 1,2,4,8 (default=1)
F: debug
TEST:
*)bulk size is specified as rszlo/rszhi=[1,4,64,1024K]
*)TH is specified as thrlo/thrhi=[1,2,4,8]
*)the amount of objects to work on in parallel: crglo=crghi=[1;TH]
i.e. test only cases when all the threads work on the same file and
when all of them work on a separate file.
TEST=[bulk;separate or commin file]=8 tests;

Test matrix(TESTxTHxDISK):
Run TESTs with different amount of threads for each DISK.
TESTxTHxDISK=(8x4 - 1)x3=93 tests.
"-1" because TH=1 is already covered.

Total:93 tests.

*** NETT1. lnetself test.***

RAM: fixed
CPU: 1,8,32 (default=1)
DISK: -
JOUR:-
CL: 1,8 (default=1)
OSS:1
NET: GiGe, IB (default=IB)
OSTN:1
TH: 1,2,4,8 (default=1)
F: debug
TEST:
*) test type: PING,READ,WRITE tests
*) bulk size for READ/WRITE: 1k,4k,64k,1M
[1 ping + 4 reads + 4 writes] = 9 tests

Test matrix (TESTxCLxTHxNETxCPU):
1. Multi-thread test.
Run TESTs on CL=1 with different amount of threads.
TESTxTH=[1+4+4]x4=36 tests.
2. Multi-client test
Note: to be more demonstrative, the maximum amount of threads could be  
taken <8,
if TH=8 reaches the maximum network throughput with small amount of  
clients.
TESTxCLxTH=9x1x4=36 tests.
3. Network test
As the nature of IB is different from GiGe, we need to repeat all the  
tests from (1,2) here.
36+36=72 tests.
4. CPU test
Note: lnet fixes from Liang to be applied here.
Run TESTs on different amount of CPU.
It is mostly interesting to look at large amount of threads, as we are
going to benefit from handling them in parallel.
At the same time, if some HW (network) limit is reached, the result  
will not be
very demonstrative, so test with 1 small & 1 large bulk size only:[1k; 
1024K]:
[CL=8,TH=1,2,4,8]. TESTxCLxTHxCPU=5x1x4x(3-1)=40.

Total: 184 tests.

*** NETT2. OBD performance ***
lustre-iokit: obdfilter-survey, case=network.
	
The results of this tests are to be compared with lnet results to get
the osc+ost+ptlrpc overhead.

RAM: fixed
CPU: 1
DISK: -
JOUR:-
CL: 1,8 (default=1)
OSS:1
NET: IB
OSTN:1
TH: 1,2,4,8 (default=1)
F: debug
TEST:
*) bulk size: rszlo=rszhi=N (1,4,64,1024)
*) TH is specified through: thrlo=1, thrhi=8 (thread count, 1,2,4,8)
*) the amount of objects is: nobjlo=nobjhi=[1;TH]
i.e. test only cases when all the threads work on the same file and
when all of them work on a separate file.
TEST=[4 bulks; common or separate file]=8 tests

Test matrix(TESTxTHxCL):
1. Multi-thread test.
Run TESTs on CL=1 with different amount of threads. TESTxTH=8x4=32 tests
2. Multi-client test
Note: to be more demonstrative, the maximum amount of threads should  
be taken <8,
if TH=8 reaches the maximum network throughput with small amount of  
clients.
TESTxCLxTH=8x1x4=32 tests.
3. Network test.
Having IB results in hand after (1,2) and these results from NETT1, we  
already see how
osc+ost+ptlrpc changes the behavior. There is no reason to repeat them  
for GiGe, it seems.
4.CPU test
Note: lnet fixes from Liang to be applied here.
Run TESTs on different amount of CPU.
It is mostly interesting to look@large amount of threads, as we are
going to benefit from handling them in parallel.
At the same time, if some HW (network) limit is reached, the result  
will not be
very demonstrative, so test with 1 small & 1 large bulk size only:[1k; 
1024K]:
[CL=8,TH=1,2,4,8]. TESTxCLxTHxCPU=4x1x4x(4-1)=48.

Total: 112 tests.

*** OSTT1. Isolated OST ***
lustre-iokit: obdfilter-survey, case=disk

The results of this tests are to be compared with LLT results to get  
the OST
stack overhead.

RAM: fixed
CPU: 1,8,32 (default=1)
DISK: raid, fake (default=fake)
JOUR: int, ext, ram, (default=ext)
CL: 1
OSS:1
NET: -
OSTN:1,2,4 (default=1)
TH: 1,2,4,8 (default=1)
F: debug
TEST:
*) bulk size: rszlo=rszhi=N (1,4,64,1024K)
*) TH is specified through: thrlo=1, thrhi=8 (1,2,4,8)
*) each OST is supposed to be configured on a separate disk.
*) the amount of objects is: nobjlo=nobjhi=[1;TH]
i.e. test only cases when all the threads work on the same file and
when all of them work on a separate file.
TEST=[4 bulks; common of separate file]=8 tests

Test matrix(TESTxTHxOSTNxDISKxJOURxCPU):
1. Multi-thread test.
Run TESTs on OSTN=1 with different amount of threads. TESTxTH=8x4=32  
tests
2. Multi-OST test
2.1. Let's check how OSTs vs. threads per OST scale (TH=OSTN).
2.2. Let's check how the system scale with many OSTs and threads  
(TH=8*OSTN).
[OSTN>1;TH=OSTN,8*OSTN]. TESTxOSTNxTH=8x2x2=32 tests.
3. DISK test
As other disks are completely different, so lets repeat most of the  
(1,2) for 2 others:
[TH=OSTN;8*OSTN]: TESTxOSTNxTHxDISK=8x3x2x1=48
4. JOURNAL test.
Limit the tests with only raid-disk.
Limit the test with only 1 large and 1 small bulk:[1,1024K].
TESTxOSTNxTHxJOUR: 4x3x2x2=48
5. CPU test
Note: lnet fixes from Liang to be applied here.
Run TESTs on different amount of CPU. It is better to perform it on a  
fast
backend (DISK=fake) to see how CPU really matters.
It is mostly interesting to look at large amount of threads, as we are  
going
to benefit from handling them in parallel.
Also, run with a small & a large bulk only:[1,1024K]
[OSTN=4,TH=1,2,4,8]: TESTxOSTNxTHxCPU=4x1x4x2=32

Total: 192 tests.

*** OSTT2. Real OST test ***
lustre-iokit: obdfilter-survey, case=netdisk

This test is a composition of OBD performance and Isolated OST tests,
so its results are to be compared with NETT2 & OSTT1 results.

RAM: fixed
CPU: 1,8,32 (default=1)
DISK: fake
JOUR: ext
CL: 1,8 (default=1)
OSS:1,2,4 (default=1)
NET: IB
OSTN:1,2,4 (default=1)
TH: 1,2,4,8 (default=1)
F: debug
TEST:
*) bulk size: rszlo=rszhi=N (1,4,64,1024)
*) TH is specified through: thrlo=1, thrhi=8 (thread count, 1,2,4,8)
*) each OST is supposed to be configured on a separate disk.
*) the amount of objects is: nobjlo=nobjhi=[1;TH]
i.e. test only cases when all the threads work on the same file and
when all of them work on a separate file.
TEST=[4 bulks; common of separate file]=8 tests

Test matrix(TESTxTHxCLxCPUxOSSxOSTN):
1. Multi-thread test.
Run TESTs on CL=1 with different amount of threads. TESTxTH=8x4=32 tests
2. Multi-client test
Note: to be more demonstrative, the maximum amount of threads could be  
taken <8,
if TH=8 reaches the maximum network throughput with small amount of  
clients.
TESTxCLxTH=8x1x4=32 tests.
3. Network test
Having IB results in hand after (1,2) and these results from NETT2, we  
already see how
osc+ost+ptlrpc+obdfilter changes the behavior. Thus, there is no  
reason to repeat them
for GiGe, it seems.
4.CPU test
Note: lnet fixes from Liang to be applied here.
Run TESTs on different amount of CPU.
It is mostly interesting to look at large amount of threads, as we are
going to benefit from handling them in parallel.
At the same time, if some HW (network) limit is reached, the result  
will not be
very demonstrative, so test with 1 small & 1 large bulk size only:[1k; 
1024K]:
[CL=8,TH=1,2,4,8]. TESTxCLxTHxCPU=4x1x4x(3-1)=32.
5. OSTN test.
The same OSC, network, CPU, disk, just check how OST stack (see 1,2  
tests) is scalable.
5.1. Let's check how N threads per 1 OST vs. 1 thread per N OST scales  
(CL=OSTN).
5.2. Let's check how the system scale with many clients and threads  
(CL=8)
Note: to be more demonstrative, the maximum amount of threads could be  
taken <8,
if TH=8 reaches the maximum network throughput with small amount of  
clients.
As the different with (1,2) on the OSS part only, it is enough to test  
in separate directories
only.  It seems enough to look at 1 small & 1 large bulk only: [1,1024K]
[CL=OSTN,8;TH=1,8]. TEST=2. TESTxCLxTHxOSTN=2x2x2x2=16 tests
6. OSS test.
6.1. Let's check how 1 thread per N OST vs. 1 thread per N OSS scales  
(CL=OSS).
6.2. Let's check how the system scale with many clients and threads  
(CL=8)
Note: to be more demonstrative, the maximum amount of threads could be  
taken
<8, if TH=8 reaches the maximum network throughput with small amount  
of clients.
As the different with (1,2) on the OSS part only, it is enough to test  
in separate directories
only. It seems enough to look at 1 small & 1 large bulk only: [1,1024K]
[CL=OSS,8;TH=1,8]. TEST=2. TESTxCLxTHxOSTN=2x2x2x2=16 tests

Total:128 tests

*** OSTT3. Client-OST test ***
lustre-iokit: ior-survey.

The test results are to be compared with OSTT2 results to get the  
overhead
for Lustre Client: client stack, distributed locking, etc.

RAM: fixed
CPU: 1,8,32 (default=1)
DISK: fake
JOUR: ext
CL: 1,8 (default=1)
OSS:1,2,4 (default=1)
NET: IB
OSTN:1,2,4 (default=1)
TH: 1,2,4,8 (default=1)
F: debug
TEST:
*) CL is specified through $clients_hi
*) TH is specified through $tasks_per_client_hi
*) bulk is specified through  rsize_lo/hi (1,4,64,1028K)
*) file_per_task=[0;1]
i.e. test only cases when all the threads work on the same file and
when all of them work on a separate file.
TEST=[4 bulks; common of separate file]=8 tests

Test matrix(TESTxTHxCLxCPUxOSSxOSTN): absolutely the same as for OSTT2.

NETT3. MD: (not ready)
MDST1. Isolated MDS (not ready)
MDST2. Remote MDS (not ready)
This set of tests need to be implemented in a utility similar to  
obdfilter-survey
but for MDS testing.

MDST3. Simple Client-MDS operation tests

1. create,mknod,mkdir (symlink, link??)
RAM: fixed
CPU(MDS): 1,8,32 (default=1)
DISK(MDS): ramdisk, raid (default=ramdisk)
DISK(OST): raid
JOUR(MDS): int,ext,ram (default=ext)
CL: 1,8 (default=1)
MDS:1,2,4 (default=1)
OSS:1,2,4 (default=1)
NET: IB
OSTN:1
TH: 1,2,4,8 (default=1)
F: debug
TEST: it will be probably mdsrate/mdsrate-create-small.sh, but it  
needs to be
fixed to support all of these operations, not only create. If so:
*) TH could be specified through THREADS_PER_CLIENT=[1,2,4,8]
*) CL is specified through CLIENTS  or NODES_TO_USE.
*) NOSINGLE should be provided
*) add --dirnum option to COMMAND
*) DIRNUM=[1,TH*CL], so we test a case when all the threads work in the
same dir and when each works in a separate one.
*) nfiles is files-per-dir * DIRNUM
[common or separate dir]=2tests;

Note: we should probably limit the amount of files in 1 directory with  
2M,
otherwise the performance will definitely downgrade.

Test matrix(TESTxTHxCLxCPUxMDSxOSSxDISKxJOUR):
1. Multi-thread test. (mknod)
Run TESTs on CL=1 with different amount of threads. TESTxTH=2x4-1=7  
tests
(not 8 as if TH=1, DIRNUM=1, and this is already covered).
2. Multi-client test (mknod)
Note: to be more demonstrative, the maximum amount of threads could be  
taken <8,
if TH=8 reaches the maximum network throughput with small amount of  
clients.
TESTxCLxTH=2x1x4=8 tests.
3. OSS (create)
3.1. Let's check how multi-client system scales (TH=OSS).
3.2. Let's check how large load system scales (TH=8)
As the different with (1,2) on the OSS part only, it is enough to test  
in separate directories
only. Stripeness is [1, -1]. TEST=2. TESTxCLxTHxOSS=[2x2x2]x2 +  
[2x2x2]x1(1OSS case)=24
4. Network test
Having IB results in hand after (1,2,3) and these results from NETT1,  
we already see
how mdc+mdt-stack+ptlrpc changes the behavior. There is no reason to  
repeat them
for GiGe, it seems.
5. DISK test. (mknod)
Unlike the OST testing, we do not have echo-md client (MDTT1), thus we  
have not checked
how different disks impact the performance, so we need to check it here.
As difference disks are of completely different nature we need to  
repeat most of (1,2) here
[TH=1,8]: TESTxCLxTHxDISK=(2x2x2-1)x1=7
6. JOURNAL test. (mknod)
Repeat (5) for different journals, but limit the test with raid-disk  
only.
TESTxCLxTHxDISKxJOUR=(2x2x2-1)x1x2=15
7.CPU test (mknod)
Note: lnet fixes from Liang to be applied here.
Run TESTs on different amount of CPU.
It is mostly interesting to look at large amount of threads, as we are
going to benefit from handling them in parallel, so run it for CL=8 only
TESTxCLxTHxCPU=2x1x4x(3-1)=16
8. CMD test. (mkdir)
8.1. Let's check how N threads per 1 MDS vs. 1 thread per N MDS scales  
(CL=MDS).
8.2. Let's check how the system scale with many clients and threads  
(CL=8)
Note: to be more demonstrative, the maximum amount of threads could be  
taken <8,
if TH=8 reaches the maximum network throughput with small amount of  
clients
These test happens in a separate directory (for each thread) only,  
enough to test with
nid creation policy only. TEST=1. TESTxCLxTHxMDS=1x2x4x2=16 tests.

Total: 16 tests for mkdir, 53 for mknod, 24 for create.

2. stat

RAM: fixed
CPU(MDS): 1,8,32 (default=1)
DISK(MDS): ramdisk
DISK(OST): raid
JOUR: ext
CL: 1,8 (default=1)
MDS: 1,2,4 (default=1)
OSS:1,2,4 (default=1)
NET: IB
OSTN:1
TH: 1,2,4,8 (default=1)
F: debug
TEST: mdsrate/mdsrate-stat-small.sh
*) add THREADS_PER_CLIENT to the script to specify TH
*) CL is specified through CLIENTS  or NODES_TO_USE.
*) NOSINGLE should be provided
*) add --dirnum option to COMMAND
*) DIRNUM=[1,TH*CL], so we test a case when all the threads work in the
same dir and when each works in a separate one.
*) nfiles is files-per-dir * DIRNUM
*) add READDIR_ORDER to test readdir access order (random order is not  
very
interesting for stat).
	[common or separate dir; readdir order]=2 tests.

Test matrix(TESTxTHxCLxCPUxMDSxOSS):
1. Multi-thread test.
Run TESTs on CL=1 with different amount of threads. TESTxTH=2x4-1=7  
tests
(not 16 as if TH=1, DIRNUM=1, and this is already covered).
2. Multi-client test
Note: to be more demonstrative, the maximum amount of threads could be  
taken <8,
if TH=8 reaches the maximum network throughput with small amount of  
clients.
TESTxCLxTH=2x1x4=8 tests.
3. OSS.
3.1. Let's check how multi-client system scales (TH=OSS).
3.2. Let's check how large load system scales (TH=8)
As the difference with (1,2) on the OSS part only, it is enough to  
test in separate directories
only. Test must be done for create with different stripeness: [1, -1].  
TEST=2.
TESTxCLxTHxOSS=[2x2x2]x2=16
4.CPU test
Note: lnet fixes from Liang to be applied here.
Run TESTs on different amount of CPU.
It is mostly interesting to look at large amount of threads, as we are
going to benefit from handling them in parallel, so run it for CL=8  
only.
TESTxCLxTHxCPU=2x1x4x(3-1)=16
5. CMD test. (mkdir)
5.1. Let's check how N threads per 1 MDS vs. 1 thread per N MDS scales  
(CL=MDS).
5.2. Let's check how the system scale with many clients and threads  
(CL=8)
Note: to be more demonstrative, the maximum amount of threads could be  
taken <8,
if TH=8 reaches the maximum network throughput with small amount of  
clients.
1 creation policy (nid) is enough: TESTxCLxTHxMDS=2x2x4x2=32 tests.

Total: 79 tests.

3. unlink (mdsrate-create-small.sh)

RAM: fixed
CPU(MDS): 1,8,32 (default=1)
DISK(MDS): ramdisk, raid (default=ramdisk)
DISK(OST): raid
JOUR(MDS): int,ext,ram (default=ext)
CL: 1,8 (default=1)
MDS:1,2,4 (default=1)
OSS:1,2,4 (default=1)
NET: IB
OSTN:1
TH: 1,2,4,8 (default=1)
F: debug
TEST: it will be probably mdsrate/mdsrate-create-small.sh, but it  
needs to be
fixed to support all of these operations, not only create. If so:
*) TH could be specified through THREADS_PER_CLIENT=[1,2,4,8]
*) CL is specified through CLIENTS  or NODES_TO_USE.
*) NOSINGLE should be provided
*) add --dirnum option to COMMAND
*) DIRNUM=[1,TH*CL], so we test a case when all the threads work in the
same dir and when each works in a separate one.
*) nfiles is files-per-dir * DIRNUM
*) add an ability to remove in readdir order to mdsrate test and its  
script.
	[readdir or _create_ order; common or separate dir]=3 (skip readdir/ 
common dir).

Note: we should probably limit the amount of files in 1 directory with  
2M,
otherwise the performance will definitely downgrade.

Test matrix(TESTxTHxCLxCPUxMDSxOSSxDISKxJOUR):
1. Multi-thread test. (mknod)
Run TESTs on CL=1 with different amount of threads. TESTxTH=3x4-2=10  
tests
2. Multi-client test (mknod)
Note: to be more demonstrative, the maximum amount of threads could be  
taken <8,
if TH=8 reaches the maximum network throughput with small amount of  
clients.
TESTxCLxTH=3x1x4=12 tests.
3. OSS (create)
3.1. Let's check how multi-client system scales (TH=OSS).
3.2. Let's check how large load system scales (TH=8)
As the difference with (1,2) on the OSS part only, it is enough to  
test in separate directories
only. Stripeness is [1, -1]. TEST=4. TESTxCLxTHxOSS=[4x2x2]x2 +  
[4x2x2]x1(1OSS case)=48
4. Network test
Having IB results in hand after (1,2,3) and these results from NETT1,  
we already see
how mdc+mdt-stack+ptlrpc changes the behavior. There is no reason to  
repeat them
for GiGe, it seems.
5. DISK test. (mknod)
Unlike the OST testing, we do not have echo-md client (MDTT1), thus we  
have not checked
how different disks impact the performance, so we need to check it here.
As different disks are of completely different nature we need to  
repeat most of (1,2) here
[TH=1,8]: TESTxCLxTHxDISK=(3x2x2-2)x1=10
6. JOURNAL test. (mknod)
Repeat (5) for different journals, but limit the test with raid-disk  
only.
TESTxCLxTHxDISKxJOUR=(3x2x2-2)x2=20
7.CPU test (mknod)
Note: lnet fixes from Liang to be applied here.
Run TESTs on different amount of CPU.
It is mostly interesting to look at large amount of threads, as we are
going to benefit from handling them in parallel, so run it for CL=8 only
TESTxCLxTHxCPU=3x1x4x(3-1)=24
8. CMD test. (mkdir)
8.1. Let's check how N threads per 1 MDS vs. 1 thread per N MDS scales  
(CL=MDS).
8.2. Let's check how the system scale with many clients and threads  
(CL=8)
Note: to be more demonstrative, the maximum amount of threads could be  
taken <8,
if TH=8 reaches the maximum network throughput with small amount of  
clients
These test happens in a separate directory (for each thread) only,  
enough to test with
nid creation policy only. TEST=2. TESTxCLxTHxMDS=2x2x4x2=32 tests.

Total: 32 tests for mkdir, 76 for mknod, 48 for create.

4. find (not ready)

**** MT. Mixed testing. ****

MT1. Create-write test.
RAM: fixed
CPU(MDS): 1,8,32 (default=32)
DISK(MDS): ramdisk, raid (default=ramdisk)
DISK(OST): raid
JOUR: ext
CL: 1,8 (default=1)
MDS: 1,2,4 (default=1)
OSS:1
NET: IB
OSTN:1
TH: 1,2,4,8 (default=1)
F: debug
TEST: must be a new one. Each thread creates files in a loop, writes 1  
bulk to each and closes it.
*) it is enough to test with a small bulk only: [1k]
*) [common or separate dir]=2tests;

Test matrix(TESTxTHxCLxCPUxMDSxDISK):
1. Multi-thread test.
Run TESTs on CL=1 with different amount of threads. TESTxTH=2x4-1=7  
tests
(not 8 as if TH=1, it is always in 1 dir, and this is already covered).
2. Multi-client test
Note: to be more demonstrative, the maximum amount of threads could be  
taken <8,
if TH=8 reaches the maximum network throughput with small amount of  
clients.
TESTxCLxTH=2x1x4=8 tests.
3. DISK test.
Check how different disks impact on the performance.
As different disks are of completely different nature we need to  
repeat most of (1,2) here
[TH=1,8]: TESTxCLxTHxDISK=(2x2x2-1)x1=7
4.CPU test
Note: lnet fixes from Liang to be applied here.
Run TESTs on different amount of CPU.
It is mostly interesting to look at large amount of threads, as we are
going to benefit from handling them in parallel, so run it for CL=max
only: [CL=8,TH=1,2,4,8]. TESTxCLxTHxCPU=2x1x4x(4-1)=24
5. CMD test.
5.1. Let's check how N threads per 1 MDS vs. 1 thread per N MDS scales  
(CL=MDS).
5.2. Let's check how the system scale with many clients and threads  
(CL=8)
Note: to be more demonstrative, the maximum amount of threads could be  
taken
<8, if TH=8 reaches the maximum network throughput with small amount  
of clients
These test happens in a separate directory (for each thread) only,  
creation policy=[nid,name].
TEST=2. TESTxCLxTHxMDS=2x2x4x2=32 tests.

Total: 78 tests.

MT2. Create-Readdir test.
RAM: fixed
CPU(MDS): 1,8,32 (default=32)
DISK(MDS): ramdisk, raid (default=ramdisk)
DISK(OST): raid
JOUR: ext
CL: 1,8 (default=1) (1 extra client does "ls -U")
MDS:1,2,4 (default=1)
OSS:1
NET: IB
OSTN:1
TH: 1,2,4,8 (default=1)
F: debug
TEST: must be a new one. Each thread creates files in a loop and  
immediately closes them.
1 thread on another client does "ls -U". It is done in 1 directory.

The test matrix is exactly the same as for MT1. Total: 78 tests.

MT3. untar a kernel.
MT4. pmake (compile a kernel).
RAM: fixed
CPU(MDS): 1,8,32 (default=32)
DISK(MDS): ramdisk, raid (default=ramdisk)
DISK(OST): raid
JOUR: ext
CL: 1
MDS:1,2,4 (default=1)
OSS:1,2,4 (default=1)
NET: IB
OSTN:1
TH: 1
F: debug
TEST: a new one.

Test matrix(TESTxCPUxMDSxOSSxDISK):
1. DISK test.
Check how different disks impact on the performance. TESTxDISK=1
2.CPU test
Note: lnet fixes from Liang to be applied here.
Run TESTs on different amount of CPU.
It is mostly interesting to look@large amount of threads, as we are  
going to benefit from
handling them in parallel, so run it for CL=max only: TESTxCPU=1x(3-1)=2
3. CMD test.
Creation policy=name. TESTxMDS=1x2=2 tests.
4. OSS
As most of the files are small, stripeness does not play any role (=1)
TESTxOSS=1x(3-1)=2.

Total: 7 tests.

MT5. ??? Some more tests ????

**** Goal2. Compare HEAD and b1_6 (b1_8) performance. ****

This paragraph describes the testing methodology in the reverse order  
of testing,
i.e. in the top-bottom direction, making sure new LustreFS (HEAD)  
version does
not downgrade comparing with the previous ones (b1_6/b1_8).

Therefore, the first testing cycle includes:
1) MT, MDST3, OSTT3, NETT1 from the above tests.
2) no CMD tests

In the case a downgrade is detected, lower layer tests are to be run  
until the downgrade
disappear.

**** Goal3. CMD testing. ****

MT, MDST3 tests, their CMD sections.

**** Goal4. Quick weekly MD performance test. ****

1) It covers tests described in MT,MDST sections.
2) MDST: No CPU,OSS,OSTN tests
3) MT: no MT1,MT2 tests
4) Only 1 node configuration:
	MDS on RAID1+0 with write back cache
	OSS on RAID6 with write through cache
	JOUR: external for both servers;
5) Only 1 network:
	IB;
6) Minimal amount of cluster configurations:
	MDS=1; OST=1; [CL,TH]=[1,1],[1,8],[8,8];

MDST1.1: perform only create (not mkdir,mknod) for [common or separate  
dir]=2.
1. Multi-thread test. TESTxTH=2x2-1=3 tests
2. Multi-client test. TESTxCLxTH=2x1x1=2 tests.
Total: 5 tests.

MDST1.2. stat for [common or separate dir; readdir order]=2 tests.
1. Multi-thread test. TESTxTH=2x2-1=3 tests
2. Multi-client test. TESTxCLxTH=2x1x1=2 tests.
Total: 5 tests.

MDST1.3 unlink for [readdir or _create_ order; common or separate dir]=3
(skip readdir/common dir). All tests are done against create (not  
mkdir,mknod).
1. Multi-thread test. TESTxTH=3x2-2=4 tests
2. Multi-client test (mknod) TESTxCLxTH=3x1x1=3 tests.
Total: 7 tests.

MT3. untar a kernel.
MT4. pmake (compile a kernel).
Total: 1 tests.

Total: 19 tests.

--
Vitaly

[Lustre-devel] LustreFS performance (update)

[Andrew C. Uselton]

Howdy Vitaly,
   I like this.  It is quite comprehensive and detailed.  I'd like to 
offer a few constructive criticisms in hope that you will better achieve 
your goals.  Mostly I'll stick them in-line where they seem relevant, 
but I'll start with:
1)  Your write up is quite dense and terse.  I could follow the overall 
structure, but found it pretty tough going to understand any specific 
detail.  It really helps to work with someone who will write up the same 
information, but in a form with whole sentences and a minimum of 
acronyms or special symbols.  Define the acronyms you do use in a clear 
way in one place that I can refer back to.


Vitaly Fertman wrote:
> ****************************************************
> 	LustreFS benchmarking methodology.
> ****************************************************
> 
> The document aims to describe the benchmarking methodology which helps
> to understand the LustreFS performance and reveal LustreFS bottlenecks  
> in
> different configurations on different hardware, to ensure the next  
> LustreFS
> release does not downgrade comparing with a previous one. In other  
> words:
> 	Goal1. Understand the HEAD performance.
> 	Goal2. Compare HEAD and b1_6 (b1_8) performance.
> 
> To achieve the Goal1, the methodology suggests to test different  
> layers of
> software in the bottom-top direction, i.e. the underlying back-end,  
> the target
> server sitting on this back-end, the network connected to this target  
> and how
> the target performs through this network, etc up to the whole cluster.

I like this approach.  My own efforts tend to be at-scale testing at the 
whole-cluster end of the range, often in the presence of other cluster 
activity.  It is good to have the details of the underlying components 
documented.

...
> Obviously, it is not possible to perform all the thousands of tests in  
> all the configurations,
> running all the special purpose tests, etc, the document tries to  
> prepare:
> 1) all the essential and sufficient tests to see how the system  
> performs in general;
> 2) some minimal amount of essential tests to see how the system scales  
> in different
> conditions.

In some cases it's obvious, but in many it is not clear what exactly you 
mean to be testing.  It is a good extension to your methodology to state 
clearly not only the mechanics of the test itself, but what you think 
you are testing with the given experiment.  Spend a little time and 
describe what the system is under examination, how it responds or should 
respond to the proposed test, and what tunables and parameters you think 
might be relevant.  For instance, if the test is supposed to saturate 
the target server, then how much I/O do you expect will be required and 
why?  What timeout or other tunable may determine the observed 
saturation point.  Your goal should be to have, not only a test, but a 
real expectation about its results even before you run the test.  Once 
you have that expectation then you can evaluate the results.  The bottom 
up approach helps with this, since you can use the performance of the 
individual pieces to help establish your expectation about the larger 
assemblies.

...
> **** Hardware Requirements. ****
> 
> The test plan implies that we change only 1 parameter (cpu or disk or  
> network)
> on each step. The HW requirements are:
> 
> -- at least 1 node with:
>   CPU:32;
>   RAM: enough to have a ramdisk for MDS;
>   DISK: enough disks for raid6 or raid1+0 (as this node could be mds  
> or ost);
> 	  an extra disk for external journal;
>   NET: both GiGe and IB installed.
> -- at least 1 another node includes:
>   DISK: enough disks for raid6 or raid1+0 (as this node could be mds  
> or ost);
> 	  an extra disk for external journal;
> -- besides that: 8 clients, 3 other servers.
> -- the other servers include:
>   DISK: raid6
>   NET: IB installed.
> -- client includes:
> NET: both GiGe and IB installed.
> 
> **** Software requirements ****
> 
You might provide links to these tests for those not familiar with them.
> 1. Short term.
> 1.1 mdsrate
> to be completed to test all the operations listed in MDST3 (see below).
> 1.2 mdsrate-**.sh
> to be fixed/written to run mdsrate properly and test all the  
> operations listed in
> MDST3 (see below).
> 1.3. fake disk
> implement FAIL flag and report 'done' without doing anything in  
> obdfilter to get
> a low-latency disk.
> 1.4. MT.
> add more tests here and implement them.
> 
> 2. Long term.
> 2.1. mdtstack-survey
> - an echo client-server is to be written for mds similar to ost.
> - a test script similar to obdfilter-survey.sh is to be written.
> 
> **** Different configurations ****
> 
...

I'll cut it short here, but in general, I think you might be surprised 
that if you organize this document so that anyone else could come along 
behind you and perform all the same tests in the same way, you might get 
a lot of others doing these experiments along side you.  That would make 
your job a lot easier and increase the likelihood that bugs and 
regressions would be caught quickly.

> --
> Vitaly
> _______________________________________________
> Lustre-devel mailing list
> Lustre-devel at lists.lustre.org
> http://lists.lustre.org/mailman/listinfo/lustre-devel

Cheers,
Andrew

[Lustre-devel] LustreFS performance (update)

[parinay kondekar]

The wiki :: https://wikis.clusterfs.com/intra/index.php/LustreFS_performance

~p

Vitaly Fertman wrote:
> ****************************************************
> 	LustreFS benchmarking methodology.
> ****************************************************
>
>   

[Lustre-devel] LustreFS performance (update)

[Vitaly Fertman]

Hi Andrew,

thanks for you feedback,
indeed, this still looks more like a raw test list than a ready for  
publishing
document, but this is a continuous work and I am still working on it,  
so I will
try to address you suggestions.

On Mar 19, 2009, at 11:16 PM, Andrew C. Uselton wrote:

> Howdy Vitaly,
>  I like this.  It is quite comprehensive and detailed.  I'd like to  
> offer a few constructive criticisms in hope that you will better  
> achieve your goals.  Mostly I'll stick them in-line where they seem  
> relevant, but I'll start with:
> 1)  Your write up is quite dense and terse.  I could follow the  
> overall structure, but found it pretty tough going to understand any  
> specific detail.  It really helps to work with someone who will  
> write up the same information, but in a form with whole sentences  
> and a minimum of acronyms or special symbols.  Define the acronyms  
> you do use in a clear way in one place that I can refer back to.
>
>
> Vitaly Fertman wrote:
>> ****************************************************
>> 	LustreFS benchmarking methodology.
>> ****************************************************
>> The document aims to describe the benchmarking methodology which  
>> helps
>> to understand the LustreFS performance and reveal LustreFS  
>> bottlenecks  in
>> different configurations on different hardware, to ensure the next   
>> LustreFS
>> release does not downgrade comparing with a previous one. In other   
>> words:
>> 	Goal1. Understand the HEAD performance.
>> 	Goal2. Compare HEAD and b1_6 (b1_8) performance.
>> To achieve the Goal1, the methodology suggests to test different   
>> layers of
>> software in the bottom-top direction, i.e. the underlying back- 
>> end,  the target
>> server sitting on this back-end, the network connected to this  
>> target  and how
>> the target performs through this network, etc up to the whole  
>> cluster.
>
> I like this approach.  My own efforts tend to be at-scale testing at  
> the whole-cluster end of the range, often in the presence of other  
> cluster activity.  It is good to have the details of the underlying  
> components documented.
>
> ...
>> Obviously, it is not possible to perform all the thousands of tests  
>> in  all the configurations,
>> running all the special purpose tests, etc, the document tries to   
>> prepare:
>> 1) all the essential and sufficient tests to see how the system   
>> performs in general;
>> 2) some minimal amount of essential tests to see how the system  
>> scales  in different
>> conditions.
>
> In some cases it's obvious, but in many it is not clear what exactly  
> you mean to be testing.  It is a good extension to your methodology  
> to state clearly not only the mechanics of the test itself, but what  
> you think you are testing with the given experiment.  Spend a little  
> time and describe what the system is under examination, how it  
> responds or should respond to the proposed test, and what tunables  
> and parameters you think might be relevant.  For instance, if the  
> test is supposed to saturate the target server, then how much I/O do  
> you expect will be required and why?  What timeout or other tunable  
> may determine the observed saturation point.  Your goal should be to  
> have, not only a test, but a real expectation about its results even  
> before you run the test.  Once you have that expectation then you  
> can evaluate the results.  The bottom up approach helps with this,  
> since you can use the performance of the individual pieces to help  
> establish your expectation about the larger assemblies.
>
> ...
>> **** Hardware Requirements. ****
>> The test plan implies that we change only 1 parameter (cpu or disk  
>> or  network)
>> on each step. The HW requirements are:
>> -- at least 1 node with:
>>  CPU:32;
>>  RAM: enough to have a ramdisk for MDS;
>>  DISK: enough disks for raid6 or raid1+0 (as this node could be  
>> mds  or ost);
>> 	  an extra disk for external journal;
>>  NET: both GiGe and IB installed.
>> -- at least 1 another node includes:
>>  DISK: enough disks for raid6 or raid1+0 (as this node could be  
>> mds  or ost);
>> 	  an extra disk for external journal;
>> -- besides that: 8 clients, 3 other servers.
>> -- the other servers include:
>>  DISK: raid6
>>  NET: IB installed.
>> -- client includes:
>> NET: both GiGe and IB installed.
>> **** Software requirements ****
> You might provide links to these tests for those not familiar with  
> them.
>> 1. Short term.
>> 1.1 mdsrate
>> to be completed to test all the operations listed in MDST3 (see  
>> below).
>> 1.2 mdsrate-**.sh
>> to be fixed/written to run mdsrate properly and test all the   
>> operations listed in
>> MDST3 (see below).
>> 1.3. fake disk
>> implement FAIL flag and report 'done' without doing anything in   
>> obdfilter to get
>> a low-latency disk.
>> 1.4. MT.
>> add more tests here and implement them.
>> 2. Long term.
>> 2.1. mdtstack-survey
>> - an echo client-server is to be written for mds similar to ost.
>> - a test script similar to obdfilter-survey.sh is to be written.
>> **** Different configurations ****
> ...
>
> I'll cut it short here, but in general, I think you might be  
> surprised that if you organize this document so that anyone else  
> could come along behind you and perform all the same tests in the  
> same way, you might get a lot of others doing these experiments  
> along side you.  That would make your job a lot easier and increase  
> the likelihood that bugs and regressions would be caught quickly.
>
>> --
>> Vitaly
>> _______________________________________________
>> Lustre-devel mailing list
>> Lustre-devel at lists.lustre.org
>> http://lists.lustre.org/mailman/listinfo/lustre-devel
>
> Cheers,
> Andrew

--
Vitaly

[Lustre-devel] LustreFS performance (update)

[Eric Barton]

Vitaly,

I've been following this thread with great interest and I'd like
to chat with you about this and also the MDS performance regression
tests.  Unfortunately, I'm unlikely to be able to do that this week
and it will probably have to wait until I'm back in the UK next
week.  In the mean time...

1. Have you got a rough idea how much work it would be to write the
   software that could exercise the MDD directly?  I'd just like to
   know if we're talking days or weeks or months - we need to know
   that before we decide whether to do it.

2. I think Andrew Uselton's comments are helpful.  We cannot afford
   routinely to sample the whole performance space - there are just
   too many dimensions.  So we need to develop a performance model
   that allows us to restrict the number of measurements we need
   to be confident that there are no surprises "in between" the
   points we have sampled.   

   That means we have to start running tests as soon as possible over
   as wide a parameter range as possible, with as much hardware as
   possible.  Then we'll start to get a feel how much variability
   there is all over the space and where the "edges" and asymptotes
   are.

3. It's worthwhile taking time to analyse and present results with care.
   I've attached a spreadsheet that compares ping performance of a single
   8-core server with varying numbers of clients and client threads,
   measured using different LNET locking schemes - hp (HEAD ping), 2lp
   (HEAD modified to split the LNET global lock into 2) and 3lp (same, but
   splitting the LNET global lock into 3).

   The lower row of graphs shows ping throughput versus number of client
   nodes, with different numbers of threads per node in each series.  The
   upper row of graphs shows the same ping throughput, but plotted
   against client threads totalled over all nodes, with different numbers
   of nodes in each series.  Please note....

   a) Set axis scaling correctly so that visual comparison is accurate.

   b) The upper row of graphs shows that it's the total number of threads
      exercising the server that's most important - and that how those
      threads are distributed over client nodes seems to matter most when
      there are 8 of them.  That's absolutely _not_ obvious from looking
      at the lower row of graphs.

    Cheers,
              Eric

> -----Original Message-----
> From: lustre-devel-bounces at lists.lustre.org [mailto:lustre-devel-bounces at lists.lustre.org] On Behalf Of parinay
> kondekar
> Sent: 19 March 2009 10:47 PM
> To: Vitaly Fertman
> Cc: lustre-2.0-performance at sun.com; minh diep; Lustre Development Mailing List
> Subject: Re: [Lustre-devel] LustreFS performance (update)
> 
> The wiki :: https://wikis.clusterfs.com/intra/index.php/LustreFS_performance
> 
> ~p
> 
> Vitaly Fertman wrote:
> > ****************************************************
> > 	LustreFS benchmarking methodology.
> > ****************************************************
> >
> >
> 
> _______________________________________________
> Lustre-devel mailing list
> Lustre-devel at lists.lustre.org
> http://lists.lustre.org/mailman/listinfo/lustre-devel
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