Re: squid benchmarking results - squid-3.0 + epoll()

hai gonzalo arana,

    thanks for detailed reply.

> Looks like you are running into a CPU bottleneck. Perhaps you may want
> to add --enable-cpu-profiling to configure, and check cpu usage data
> with cache manager, or compile and link with -pg and check results with
> gprof.

I have done configuration with --enable-cpu-profiling and monitoring with cachemgr.cgi script.

> Also, verify whether CPU usage is in kernel-mode or user-mode with vmstat
> during the test (sar gives this information as well).

vmstat result when squid is running at peak load ( 180 req / sec ),

procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----
 r b swpd free buff cache si so bi bo in cs us sy id wa
 1 0 0 119024 34116 61252 0 0 0 110 11035 79 69 31 0 0
 1 0 0 99464 34144 61256 0 0 0 148 13033 26 65 35 0 0

>
> Looks like you are running with (the same?) CPU bottleneck.
>
> epoll's advantage is that CPU usage does not grow with the number of
> idle TCP connections. If the number of concurrent connections is large,
> and there are no idle connections, epoll should only give a small
> increase in throughput (no cpu is used for traversing the list of fds).
>
> Is, by any chance, throughput (in bps) slightly larger with epoll?

I did not get this. How to measure throughput (in bps)?

>
>> 008.75| Connection.cc:485: error: 1/1 (s110) Connection timed out
>> 008.75| error: raw write after connect failed
>> after these req / sec configuration setting.
>
> Try enabling SYN cookies, and running squid with ulimit -HSn 131072.

I have tuned sysctl -w net.ipv4.tcp_syncookies=1, ulimit -HSn there. But I am getting same error reply as,
Connection.cc:485: error: 1/1 (s110) Connection timed out

can we get more req / sec satisfacation for 512 MB RAM, 927.753 MHz cpu (pIIII) ??
I am using /dev/null file system for benchmarking?

Do you have benchmarking any results for squid?

regards
muthukumar
Received on Wed Dec 08 2004 - 23:20:04 MST