Re: [squid-users] Queue congestion at 60 req/sec

From: Pablo García <malevo@dont-contact.us>
Date: Sun, 10 Jun 2007 20:48:48 -0300

The objects being cached are 32K at most,
this is the busiest line of iostat -x I got

avg-cpu: %user %nice %sys %iowait %idle
                  2.49 0.00 1.99 22.39 73.13

Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s
avgrq-sz avgqu-sz await svctm %util
ida/c0d0 0.00 35.64 14.85 3.96 182.18 1148.51 91.09 574.26
   70.74 3.89 16.32 8.68 16.34
ida/c0d1 0.00 58.42 36.63 10.89 435.64 570.30 217.82 285.15
   21.17 0.81 16.56 6.98 33.17

This is a partial run for vmstat

vmstat 1
procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----
 r b swpd free buff cache si so bi bo in cs us sy id wa
 1 0 208 14528 105372 293208 0 0 75 58 0 7 1 1 88 10
 0 1 208 15168 105288 292512 0 0 400 276 1508 715 2 1 74 22
 0 0 208 14784 105324 292996 0 0 392 0 1541 932 3 1 79 18
 0 0 208 15296 105200 292600 0 0 580 0 1694 1408 3 3 63 30
 0 0 208 14912 105252 292808 0 0 304 0 1598 869 3 2 77 19
 0 2 208 14592 105332 292988 0 0 400 0 1538 971 3 1 70 26
 0 0 208 15552 105284 291996 0 0 348 972 1658 970 3 2 61 34
 0 0 208 14976 105340 292720 0 0 568 0 1710 1158 4 2 68 26
 0 2 208 14528 105400 292920 0 0 408 0 1615 965 3 1 75 22
 0 0 208 14976 105252 292808 0 0 524 0 1644 1074 4 2 70 24
 0 2 208 14592 105296 293024 0 0 376 0 1627 999 3 2 73 23

It doesn't seems so busy, any ideas ?

Best Regards, Pablo

>
>
>
>
> On 6/8/07, Adrian Chadd <adrian@creative.net.au> wrote:
> > On Fri, Jun 08, 2007, Pablo Garc?a wrote:
> > > Hi, is there any scenario, where I can find this message in the
> > > cache.log for that amount of requests ? What I'm doing wrong ?
> > > squidaio_queue_request: WARNING - Queue congestion
> > >
> > >
> > > Running as reverse proxy
> > > 2 scsi disks with cache_dir configured at 60% of the size
> > > ext3 mounted with noatime
> > > REDHAT kernel 2.6.9-55.ELsmp (4 Update 5)
> > > 2 x Pentium III 1Ghz. 1Gb RAM
> > > access_log none
> > > cache_store_log none
> > > cache_mem 256 Mb
> > >
> > >
> > > CPU at 16% IOWAIT, 4% USER and 2,6% SYSTEM
> > > 60 client req/sec, 70% hit Ratio.
> >
> > Well, you haven't given the one actual bit of info you need, which is IO
> > throughput. Run "vmstat 1" and "iostat 1", look at the device IO.
> > Are your objects big or small? If they're big then each object is going
> > to generate a whole lot more IO than smaller objects, hence the queue
> > congestion.
> >
> >
> >
> > ADrian
> >
> >
>
Received on Sun Jun 10 2007 - 17:48:50 MDT

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