Date: Tue, 09 Jul 2013 19:48:05 +1200 From: Berend de Boer <berend@pobox.com> To: Rick Macklem <rmacklem@uoguelph.ca> Cc: freebsd-fs <freebsd-fs@freebsd.org> Subject: Re: Terrible NFS4 performance: FreeBSD 9.1 + ZFS + AWS EC2 Message-ID: <87a9lwyy16.wl%berend@pobox.com> In-Reply-To: <580122426.2916694.1373242759482.JavaMail.root@uoguelph.ca> References: <87y59i0yni.wl%berend@pobox.com> <580122426.2916694.1373242759482.JavaMail.root@uoguelph.ca>
next in thread | previous in thread | raw e-mail | index | archive | help
--pgp-sign-Multipart_Tue_Jul__9_19:48:05_2013-1
Content-Type: text/plain; charset=US-ASCII
>>>>> "Rick" == Rick Macklem <rmacklem@uoguelph.ca> writes:
Rick> After you
Rick> apply the patch and boot the rebuilt kernel, the cpu
Rick> overheads should be reduced after you increase the value of
Rick> vfs.nfsd.tcphighwater.
OK, completely disregard my previous email. I actually was testing
against a server in a different data centre, didn't think it would
matter too much, but clearly it does (ping times 2-3 times higher).
So moved server + disks into the same data centre as the nfs client.
1. Does not effect nfs3.
2. When I do not set vfs.nfsd.tcphighwater, I get a "Remote I/O error"
on the client. On server I see:
nfsd server cache flooded, try to increase nfsrc_floodlevel
(this just FYI).
3. With vfs.nfsd.tcphighwater set to 150,000. I get very high cpu, 50%.
Performance is now about 8m15s. Which is better, but still twice
above a lower spec Linux NFS4 server, and four times slower than
nfs3 on the same box.
4. With Garrett's settings, I looked at when the cpu starts to
increase. It starts slow, but raises quickly to 50% in about 1
minute.
Time was similar 7m54s.
5. I lowered vfs.nfsd.tcphighwater to 10,000 but then it actually
became worse, cpu quickly went to 70%, i.e. not much difference
with FreeBSD without patch. Didn't keep this test running to see if
it became slower over time.
Making it 300,000 seems that the cpu increases are slower (but it
keeps rising).
So from what I observe from the patch is that it makes the rise in
cpu increase slower, but doesn't stop it. I.e. after a few minutes,
even with setting 300,000 the cpu is getting to 50%, but dropped a
bit after a while to hover around 40%. Then it crept back to over 50%.
6. So the conclusion is: this patch helps somewhat, but nfs4 behaviour
is still majorly impaired compared to nfs3.
--
All the best,
Berend de Boer
------------------------------------------------------
Awesome Drupal hosting: https://www.xplainhosting.com/
--pgp-sign-Multipart_Tue_Jul__9_19:48:05_2013-1
Content-Type: application/pgp-signature
Content-Transfer-Encoding: 7bit
Content-Description: OpenPGP Digital Signature
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.17 (GNU/Linux)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=WX8Z
-----END PGP SIGNATURE-----
--pgp-sign-Multipart_Tue_Jul__9_19:48:05_2013-1--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?87a9lwyy16.wl%berend>