[Linux-cluster] Slowness above 500 RRDs

Ferenc Wagner wferi at niif.hu
Thu Apr 26 16:36:02 UTC 2007


David Teigland <teigland at redhat.com> writes:

> Thanks, some of these numbers look odd to me; I'll need run the test on my
> own rhel4 cluster to understand them better.

I'm working with three nodes: 1, 2 and 3.  Looks like the mount by 3
makes a big difference.  When the filesystem is mounted by 1 and 2
only, my test runs much faster.  Filesystem mounted by 3 alone is also
fast.  But 3 doesn't seem to cooperate with anyone else with
reasonable performance.

If I mount the filesystem on all three nodes and run the test on 1,
the network traffic of 2 and 3 is rather unbalanced: tcpdump receives
19566 packets on 2 and 29181 on 3.  It's all 21064/tcp traffic, I can
provide detailed data if that seems useful.

> In the end, though, I think you'll get the best performance by using
> flocks under the new cluster infrastructure and kernel.

Can you point me to the relevant documentation and version numbers for
upgrading to the new cluster infrastructure?  Unfortunately it's not
prepackaged, which means much more maintenance work, but I'm willing
to test if it helps enough to justify that.
-- 
Regards,
Feri.




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