Re: [squid-users] High tcp_hit times

leongmzlist wrote:
> I think it's due to dns. Here was the squid manager output:
>
> Median Service Times (seconds) 5 min 60 min:
> HTTP Requests (All): 8.68295 2.37608
> Cache Misses: 10.20961 0.03066
> Cache Hits: 8.22659 2.79397
> Near Hits: 0.00000 0.00000
> Not-Modified Replies: 0.00000 0.00000
> DNS Lookups: 10.60242 9.70242
> ICP Queries: 0.00000 0.00000
>
> Does squid still use dns for reverse proxy requests? All my requests
> goes to http://cache-int/, but cache-int is not on /etc/hosts nor on
> DNS. I have 1 orginal-server defined and is used as the default, so
> shouldn't squid just goto the backend w/o dns lookups?

If you have ACL which require rDNS then yes. 'dst' for example when
'dstdomain' should have been used.

Amos

>
> thx,
> mike
>
>
> At 03:10 PM 6/6/2008, Henrik Nordstrom wrote:
>> On fre, 2008-06-06 at 14:38 -0700, leongmzlist wrote:
>> > My cache performance is acting strange; I'm getting extremely high
>> > tcp_hit times for cached objects:
>> >
>> > 1212787643.465 50343 10.2.7.22 TCP_HIT/200 19290 GET
>> http://cache-int/....
>> > 1212787737.740 15212 10.2.7.25 TCP_HIT/200 11511 GET
>> http://cache-int/....
>> >
>> >
>> > Those high times comes in bursts. Eg: bunch of high response time
>> > will come followed by a normal response times. Normal response times
>> > are sub 100ms
>>
>> Could be cache validations. Some times TCP_HIT is logged when it really
>> should have been TCP_REFRESH_HIT. This can happen if the object uses
>> Vary if I remember correctly.
>>
>> Another possibility is if the Squid serer is swapping, causing Squid to
>> delay everything waiting for swap activity.
>>
>> A third possibility is if you have ACLs which may cause delays, such as
>> DNS dependencies or external acl lookups.
>>
>> Regards
>> Henrik
>

-- 
Please use Squid 2.7.STABLE1 or 3.0.STABLE6