Re: [squid-users] No SWAPIN in store.log

Delcam wrote:

> can I rely on RELEASE messages in the store.log?
> How can I track up an event that an object is placed in the cache?
> i.e. it was considered as cacheable, retrieved from the source and
> stored somewhere (in-memory or on disk)?

RELEASE you can rely on if using a reasonably modern version of Squid.
However, in some older versions there has been bugs where RELEASE only
was logged if the object was also cached in memory. If you see RELEASE
entries with lots of ? in them then you are not affected by this old
bug, if you only see RELEASE entries carrying a full URL and your cache
is full then you quite likely have a Squid version with this bug.

SWAPOUT can be more or less relied upon, but it does not tell you about
what is being stored in the memory cache. The memory cache is always
used, and there will either be a RELEASE with filenumber FFFFFFFF
telling that the object was discarded and not permanently saved in the
cache or a SWAPOUT telling that the object is cached.

However, there are a few cases where things are not swapped out, and in
such case I don't think anything is logged in store.log. These are:
  1. Negatively cached responses
  2. Responses which could not be cached on disk due to overload

also I am not 100% sure how things behaves when using the "null" store.

Regards
Henrik Nordström
Squid Hacker
Received on Wed Oct 03 2001 - 04:52:04 MDT