Re: [squid-users] High cpu load with squid

On Sun, 31 Oct 2010 20:45:33 +0100, Michał Prokopiuk
<michal_at_linuxstuff.pl>
wrote:
> Hi.
> For the last few days I have had troubles with my squid (3.0.24) - it
gets
> a lot of cpu, and
> response time is very long, about 4000 ms. I didn't see any information
> in cache.log, so I tried to upgrade to latest stable release - it
> doesn't change anything. I have read a lot about high cpu usage when
squid
> rebuild disc cache, so I try change cache_dir type from ufs to aufs or
> coss (./configure said about remove coss from squid 3.x), but the
problem
> still exists.
>
> What am I doing wrong? My squid has been working perfectly for two years
> :(. Here's my config.log and squid.conf:
>
> ./configure --prefix=/usr/local/squid-3.1.8 --enable-useragent-log
> --enable-referer-log --enable-default-err-language=Polish
> --enable-err-languages=Polish --enable-linux-netfilter --enable-ssl
> --with-large-files --with-filedescriptors=16384 -enable-snmp
> --with-maxfd=16384 --with-pthreads --enable-async-io --disable-dlmalloc
> --with-aio --enable-epoll
>
> http_port 192.168.1.1:8080 transparent
> pid_filename /var/run/squid/squid.pid
> acl sloneczko src 192.168.0.0/23
> http_access allow sloneczko
> error_default_language pl-pl
>
> redirect_program /usr/local/bin/redirector.pl
> redirect_children 80

Replace those with:
  url_write_program /usr/local/bin/redirector.pl
  url_rewrite_children 80

>
> store_avg_object_size 8 kB
> minimum_object_size 1 KB
> maximum_object_size 100 MB
> maximum_object_size_in_memory 1 MB
> cache_mem 1000 MB
>
> cache_swap_low 80%
> cache_swap_high 100%

cache_swap_high should be something less than 100% (99% may be better).
Squid will ONLY begin the aggressive space clearing when cache_swap_high
threshold is passed. So with 100% this may cause active connections to be
stopped while 20% of the cache is discarded.

> # previous cache
> #cache_dir ufs /var/spool/squid-cache/cache 30000 12 256
> cache_dir aufs /var/spool/squid-cache/cache 30000 60 100
>
> dns_nameservers 192.168.1.100 192.168.1.200
> ipcache_size 8192
> fqdncache_size 1024
> positive_dns_ttl 2 hours
> negative_dns_ttl 1 minutes
> ipcache_low 90
> ipcache_high 95
>
> emulate_httpd_log on
> access_log /var/log/squid/access.log

Remove emulate... and change access_log to:
  access_log /var/log/squid/access.log common

> cache_log /var/log/squid/cache.log
> cache_store_log /dev/null

Set this to "cache_store_log none".

>
>
> Rest of squid.conf are acls. I have about 30 - 40 mbps of traffic. On

You have "http_access allow sloneczko" at the top of this config. so its
possible your other ACL are not working.

> board
> are core2duo 1.8 ghz 4 gb ram on intel chipset, 2x SATA on soft raid
(for
> cache - md0).

by "soft raid" you mean *software* raid? That is a disk IO killer for
Squid.

>
> Any ideas? When I run -k debug I can't do anything - load has increased,

> and nothing could be seen, thousands lines per second was write to
> cache.log.

During a time when things go slow what seems to be the most common
thing(s) logged?

Amos
Received on Mon Nov 01 2010 - 01:17:50 MDT