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

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