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Bug 102787

Summary: compile time threading limits are too low for busy caches
Product: Red Hat Enterprise Linux 2.1 Reporter: Red Hat Production Operations <soc>
Component: squidAssignee: Martin Stransky <stransky>
Status: CLOSED NEXTRELEASE QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: 2.1Keywords: FutureFeature
Target Milestone: ---   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Enhancement
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2006-03-07 10:44:53 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description Need Real Name 2003-08-21 03:32:46 UTC 
Description of problem:

Seen in squid's cache.log: aio_queue_request: WARNING - Queue congestion

Based on this thread, it appears that the number of threads available to squid
needs to be increased:

http://ftp.pop-mg.rnp.br/squid/mail-archive/squid-users/200111/1228.html

The current squid settings use these defaults:

#ifdef ASYNC_IO_THREADS
#define NUMTHREADS ASYNC_IO_THREADS
#else
#define NUMTHREADS (Config.cacheSwap.n_configured*16)
#endif

which defines 16 threads per cache directory configured in squid.conf.
(reference parse_cachedir() in src/cache_cf.c)

I think that changing the configure line for squid to have
"--with-aio-threads=32" would be a potential starting point.

Either that, or patching the above portion in src/fs/aufs/store_asyncufs.h to be
*32 per cache directory, so that sites already using multiple cache directories
will not be suprised by the overall number of threads decreasing if they have
more than 2 directories setup.
Comment 1 Martin Stransky 2005-11-24 13:30:36 UTC 
Is it still a problem with the latest RHELs?