disable sendfile in Varnish, please

Eirik Øverby ltning at anduin.net
Mon Dec 10 15:23:22 CET 2007


is this still a problem?

I'm running varnish in front of a midsize site (~2m hits/day), and  
have seen a couple of panics like the ones attached. It refers to  
sendfile, and fails to do a core dump (I know core dumps in general  
are functioning, as I had a couple of NIC-related ones not too long  
ago). Thus the attached "screenshot" is all I've got.

FreeBSD anduin.net 6.2-STABLE FreeBSD 6.2-STABLE #1: Sat Apr 28  
12:59:34 CEST 2007
Varnish version: varnish-1.1.1_2 (from ports)


On May 11, 2007, at 17:12, Poul-Henning Kamp wrote:

> 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
> 	-p sendfile_threshold=-1
> 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
> future.
> 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.
> _______________________________________________
> varnish-misc mailing list
> varnish-misc at projects.linpro.no
> http://projects.linpro.no/mailman/listinfo/varnish-misc

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://www.varnish-cache.org/lists/pipermail/varnish-misc/attachments/20071210/9adc9eef/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: fbsd_sendfile_panic.png
Type: image/png
Size: 57917 bytes
Desc: not available
URL: <https://www.varnish-cache.org/lists/pipermail/varnish-misc/attachments/20071210/9adc9eef/attachment-0002.png>

More information about the varnish-misc mailing list