Search squid archive

Re: High tcp_hit times

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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

[Index of Archives]     [Linux Audio Users]     [Samba]     [Big List of Linux Books]     [Linux USB]     [Yosemite News]

  Powered by Linux