Re: [squid-users] Byte Hit ratio - which data are counted?

On Thu, 11 Nov 2004, Matus UHLAR - fantomas wrote:

> I have a "farm" of 3 squid caches, eash of them now has ~10% of byte hit
> ratio. They all are proxy-only neighbours to each other.
>
> I'd like to ask, how should I count the whole farm efficiency?

Tricky when you have intra-farm peerings, more so when you use proxy-only
as there can be significant amount of traffic in such peerings.

> - should I count that 10% of all requests are fetched from cache?
>
> - should I count the total ratio higher?

It can be any of the above depending on the traffic pattern.

> - should I count that the ratio is lower

No, it is at least ~10%, or the medium of the peers hit ratio weighted by
the number of requests each peer sees. If there is significant peering
traffic then the hit ratio is somewhat higher (but probably not by very
much).

To get accurate numbers you need to sum the number of requests in hits and
misses, excluding the requests forwarded to another peer within the farm.

> - if squid fetches an object from its neighbour cache, it may and may not
> be counted to the byte hit radio

It is in such case counted as a cache miss on this proxy and a cache hit
on the neighbour.

> - if an object is fetched from squid cache by its neighbour, it may and
> may not be counted to the byte hit ratio

It is in such case counted as a cache miss on the neighbour and a cache
hit on this proxy.

Actually the same situation as the above, only difference is which of the
two received the original request from the client.

Reagrads
Henrik
Received on Thu Nov 11 2004 - 15:42:55 MST