On 07/24/2012 09:43 AM, Mehdi Abaakouk wrote:
Hi all,
I am currently doing some tests on Ceph, more precisely on the RDB and RADOSGW
parts.
My goal is to get some performance metrics according to the hardwares and
the Ceph setup.
To do so, I am preparing a benchmark how-to, to help people to compare their
metrics.
I have started the how-to here : http://ceph.com/w/index.php?title=Benchmark
I have linked it in the misc section of the main page.
Then, first question, is it alright if I continue publishing this procedure
on your wiki ?
The how-to is not finished yet, this is only a first draft.
My test platform is not ready yet too, so the result of the bench can't be
used yet.
The next work I will do on the how-to is to add some explanations on how
to interpret the results of benchmark.
So, if you have some comments, ideas of benchmarks, or anything that can be
helpful to me to improve the how-to and/or compare future results,
I would be glad to read them.
And thanks a lot for your work on Ceph, this is a great storage system :)
Best Regards,
Hi Mehdi,
Thanks for taking the time to put all of your benchmarking procedures
into writing! Having this kind of community participation is really
important for a project like Ceph. We use many of the same tools
internally and personally I think it's fine to have it on the wiki. I
do want to stress that performance is going to be (hopefully!) improving
over the next couple of months so we will probably want to have updated
results (or at least remove old results!) as things improve. Also, I'm
not sure if we will be keeping the wiki around in it's current form.
There was some talk about migrating to something else, but I don't
really remember the details.
Some comments:
- 60s is a pretty short test. You may get a more accurate
representation of throughput by running longer tests.
- Performance degradation on aged filesystems can be an issue, so you
may see different results if you run the test on a fresh filesystem vs
one that has already had a lot of data written to it.
- Depending on the number of OSDs you have you may want to explicitly
set the number of PGs when creating the benchmarking pool.
- We also have a tool called "test_filestore_workloadgen" which lets you
directly test the filestore (data disk and journal) which can be useful
when doing strace/perf/valgrind tests.
Also, We have some scripts in our ceph-tools repo that may also be
useful for anyone who is interested in performance profiling or
benchmarking. Specifically:
analysis/log_analyzer.py - lets you analyze where high latency requests
are spending their time if debugging/tracker options are turned on for
the logs.
analysis/strace_parser.py - Rough tool to let you examine the frequency
of various write/read/etc operations as reported by strace. Useful for
analyzing IO for things other than Ceph as well, but still in progress.
aging/runtests.py - A tool we use for running rados bench and rest bench
internally on multiple clients. Eventually this may be folded into our
teuthology project as much of the functionality overlaps. Requires
pdsh, collectl, blktrace, perf, and possibly some other dependencies.
Thanks,
Mark
--
Mark Nelson
Performance Engineer
Inktank
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