disable sendfile in Varnish, please
phk at phk.freebsd.dk
Fri May 11 17:12:22 CEST 2007
I've nailed three different operating system kernels as having
sendfile(2) issues today, so I would advice all of you to
disable sendfile to avoid the various problems we've seen.
The easiest way is to specify
to varnishd, or by using the CLI:
param.set sendfile_threshold -1
Only those of you with high paging rates would be in risk of seing
any performance changes as result of this.
While it is quite easy to set up a test environment to look for
sendfile trouble, we cannot do it as part of varnish runtime so I
think we will ship with sendfile_threshold at -1 for the forseeable
Once we start to see kernels where sendfile works correctly in all
instances, we can consider how to seletively enable those.
Alternatively, if nobody sees a performance loss from disabling it
now, we might as well just forget about it in toto.
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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