Re: [squid-users] I/O tests and squid

From: Ming-Ching Tiew <mingching.tiew@dont-contact.us>
Date: Tue, 14 Aug 2007 11:00:39 +0800

From: "Henrik Nordstrom" <henrik@henriknordstrom.net>
>
>
> Shouldn't have much effect on Squid as Squid is using direct POSIX I/O,
>and not C "stdio" I/O, bypassing almost all of the C library.

That's why I asked the question, what will be the test which I can
run to verify the performance of IO needed by squid. Because
when I tweak something, I need to quickly verify it instead of
putting it to life use.

I am having a system which handles about 9000 active sessions
now, and the iostat result is as such :-

avg-cpu: %user %nice %system %iowait %steal %idle
           0.92 0.00 1.09 6.16 0.00 91.83

Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sda 67.86 393.10 1233.41 27988252 87818678
sdb 48.64 152.93 999.94 10888386 71195106

As shown above everything the system is hardly stress in terms of
CPU. Everything is blocking at I/O - which I am not sure if it is
disk IO or network IO. And it seems the io wait figures is building
up. I am worried that it will continue to build up and causing bottle
necking.

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Received on Mon Aug 13 2007 - 21:01:00 MDT

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