Re: [squid-users] cache_peer weighting

> Amos Jeffries wrote:
>>> Hi Guys,
>>>
>>> Wanted to double check I hadn't screwed up my config lines before
>>> dropping a bug report....
>>
>> Good choice. :-)
>>
>> round-robin == round-robin: each server trued in sequence until all have
>> bee tried then repeats. No weighting there.
>>
>> IIRC Squid3.0 introduces weighted-round-robin for this purpose.
>> Otherwise
>> there is CARP in 2.6.
>>
>> Amos
>>
>
> Hey Amos,
>
> Hmmm, so the only way for weighting cache_peers in 2.6 is with CARP?

No, its just the most modern and one thats shown some promise in recent
benchmarking earlier this year by a large-scale user. Thier exact results
are buried back in the mailing list somewhere.
There are other algorithms, with different properties that suite differing
siutaions.

> The config manual seems to suggest otherwise:
>
> "cache_peer 172.16.1.123 sibling 3129 5500 weight=2"
>
> Or am I assuming too much here? I could be getting the wrong end of the
> stick; but it seemed like using a similar cache_peer entries to the
> above, but with a couple having the weight=100 didn't seem to change the
> way squid was choosing the cache_peer to use.

The different algorithms all work their own way, with different inputs.
round-robin you were trying is an algorithm that ignores weight.
 I think carp, closest-only, multicast-responder (weighted using ttl=) are
weighted in 2.6.
All the closest-* ones use live network loading instead of a fixed weight.

I'm not sure which config manual you got that from. The Official
Authoritative one does not include that text.
http://www.squid-cache.org/Versions/v2/2.6/cfgman/cache_peer.html
http://www.squid-cache.org/Versions/v3/3.0/cfgman/cache_peer.html

Amos
Received on Mon Dec 17 2007 - 18:21:41 MST