Re: Squid 3.2 performance question

On Tue, 2012-03-20 at 12:35 +0100, Henrik Nordström wrote:
> tis 2012-03-20 klockan 13:09 +0400 skrev Alexander Komyagin:
> > Sorry for disinformation, BIND requests are present in both RSBAC logs.
> > IOCTL's were removed by adding --disable-eui to Squid configuration
> > command, but that did not give any performance increase.
>
> ok
>
> > On Tue, 2012-03-20 at 12:37 +0400, Alexander Komyagin wrote:
>
> > > > >> Also according to logs, that clients timeouts are caused by some of new
> > > > >> connections not being spotted and accepted as well (not gone through
> > > > >> doAccept() routine from TcpAcceptor.cc).
>
> Do you have sockets hanging in SYN_SENT state?
>
> Or are they ESTABLISHED but not picked up for procssing by Squid?

Yep, looks like I have them in SYN_SENT for 5 secs and then they are
discarded (timeout for httperf is set for 5 secs).

>
>
> > > Alex, I have performed some more tests (including oprofile profiling,
> > > no-daemon mode, 1 worker, 2 workers, etc.). For now, it seems that the
> > > problem is highly related to RSBAC Networking which is enabled in our
> > > kernel. When I disabled it, the performance issue _has gone_. According
> > > to RSBAC logs, no single operation is denied.
>
> This RSBAC? http://www.rsbac.org/
>
> If so, which kernel version?

This one. 2.6.35.10 SMP x86_64.

>
> > > By comparing oprofile results for 3.2 with and w/o RSBAC-Net, I can
> > > assume that RSBAC-Net subsystem performs some internal operations on
> > > list structures, which are indeed protected by locks - and this, in my
> > > point of view, may block simultaneous squid socket operations and affect
> > > performance.
>
> Possible. We would not know.

From RSBAC logs squid 3.2 produces much more operations on NETLINK RAW
ROUTE sockets than 3.1. Maybe performance differs due to some changes in
the Squid interception mechanism in 3.2?

>
> Regards
> Henrik
>

-- 
Best wishes,
Alexander Komyagin