Re: meanings of variables in MIB?

Scott Prater wrote:

> cacheSysVMsize: size of Virtual Memory in KB. Is this the amount of
> disk space squid is currently using for as a form of virtual memory?
> Does this include swap?

It should be the size of the Squid process, as seen by ps.

> cacheMemUsage: amount of system memory allocated by the cache (subset
> of total memory squid occupies, as seen by "ps"?)

This is the amount of memory Squid has tracked. See cachemgr output for
a more detailed explanation.

> cacheNumObjectCount: number of objects in cache (total of objects in
> disk storage, in memory (current objects), and in Virtual Memory?)

Number of objects known by Squid. This includes disk objects, memory
only objects and in-transit objects.

> cacheServerRequests: total number of requests (of all kinds) to server
> from clients (value that only grows)

This is actually number of requests sent by Squid.

For number of requests received from the clients, see
cacheClientHttpRequests.

> (Is there an equivalent to the non-existent cacheServerHits value that I
> can use to determine the object hit ratio?)

Amount of cache hits is available in cacheHttpHits.

> cacheServerInKb: total number of kilobytes read from internet into
> server (value that only grows)

Yes.

> cacheServerOutKb: total number of kilobytes sent from server to clients
> (value that only grows)

No. Amount of data sent by Squid to internet servers.

The amount of data sent from Squid to it's clients is in cacheHttpOutKb

> If I understand the above cacheServerInKb and cacheServerOutKb variables
> correctly, I can obtain the byte hit ratio (as opposed to the object hit
> ratio) this way:
>
> byte hit ratio =
> (cacheServerOutKb - cacheServerInKb)/cacheServerOutKb
> the closer this number is to 1 (100%), the better my
> performance?

Bogous value. You are measuring the ratio between the requests sent by
Squid and the replies received back from other servers.

> cacheRequestHitRatio: object hit ratio (see above)
>
> cacheRequestByteRatio: byte hit ratio (see above)
>
> cacheClientHttpRequests: number of HTTP requests from client (value
> that only grows)
>
> cacheHttpHits: number of HTTP requests satisfied from within cache
> (value that only grows)
>
> cacheHttpInKb: number of KB of HTTP requests squid had to retrieve from
> outside (value that only grows)

No. Amount of data received by Squid from the browsers.

> cacheHttpOutKb: number of KB of HTTP requests squid served to clients
> (value that only grows)

Yes, but keep in mind that the only two protocols Squid accepts is HTTP
and ICP. All browser traffic counts as HTTP on the client side.

Some simple guidelines on how the variables are grouped:

cacheHttp*: Traffic to/from the brosers

cacheServer*: Traffic from when Squid requests objects from other
servers. This has sub classes for HTTP, FTP, ...

cacheIcp*: ICP traffic

--
Henrik Nordstrom