[Gluster-users] Understanding gluster performance

[Gionatan Danti]

Il 20-01-2020 16:30 Gionatan Danti ha scritto:
> So, I have some questions:
> - why performance are so low with fsync?
> - why do I have so low IOPs (20/30) for minutes?
> - what is capping the non-fsync test?
> - why both glusterd and glusterfd are so CPU intensive? I can
> understand glusterfd itself requiring more CPU, but glusterd should
> only manage the other processes and send the volume information to
> asking client, right?

An update: the very low IOPs were caused by TCP retransmission on one of 
the two boxes. After that problem was fixed, no such low performance was 
recorded.

I also think that the non-fsync tests, with about 5000 IOPs, are cappaed 
by the 1000BaseT round trip time.

Some questions remain:
- why performance are so low with fsync? (about 250 IOPs)
- why both glusterd and glusterfd are so CPU intensive?

Thanks.

-- 
Danti Gionatan
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Assyoma S.r.l. - www.assyoma.it
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