Re: Squid Startup Requirement

saleem_ak wrote:
> I am currently working on requirement if any of the cache directories are
> unavailable or unwritable, squid will not start. We would like the squid to
> only refuse to start if "no" cache_dirs are available - if more than one is
> configured but some are unavailable, we'd like it to log the error and
> continue on with the known-good cache_dir(s).
>
> I am able to do the required changes by having a global counter to track the
> clean cache directories and based on the counter value not equal to zero i
> am allowing squid to start.

You may encounter problems in future with this feature as described.
All releases of squid have an integrated memory-cache. Recent releases
of squid work on the basis that if no cache_dir are present the memory
cache is configured.

You will need to add an option to your feature to cope with that state.
For example; when turned on squid ignores cache_dir loss and drops right
back into memory-cache, but keeps running. When setting turned off,
drops back but ignores memory-cache and dies.

>
> But I am facing these problems
> 1) the directory cleanup event is trying to cleanup the unavailable or
> unwritable cache directories
> 2) the objects are tried to cached into the unavailable or unwritable cache
> directories.
>
> As I am new to the squid, I would like to get some proper direction to
> fulfill this requirement.

Is the version of squid important?
This is a major feature, and faces a large hurdle now with squid-2 being
closed to large patches.
Adrians was the last developer working on major new features for Squid-2
and even he has recently decided to abandon direct major updates to
Squid-2 in favor of a different project.

Squid-3 has a very different storage code, and is likely to be the place
where your patch is accepted into squid. The Squid-3 design can also
handle failover cases cleaner.

> I am also mentioning the error messages that i am getting with this change
>
> error messages got after the startup
> 008/04/15 10:41:31| storeDirClean: WARNING: Creating
> /usr/local/squid.2.6_cachedir/cache/05/69 2008/04/15 10:41:31|
> storeDirClean: /usr/local/squid.2.6_cachedir/cache/05/69: (2) No such file
> or directory
>
> this messages are coming during object caching
> 2008/04/17 06:35:39| storeAufsOpenDone: (2) No such file or directory
> 2008/04/17 06:35:39| /usr/local/squid.2.6_cachedir/cache/00/00/0000005E
> 2008/04/17 06:35:39| storeSwapOutFileClosed: dirno 5, swapfile 0000005E,
> errflag=-1
>
> Regards
> Saleem

Amos

-- 
Please use Squid 2.6.STABLE19 or 3.0.STABLE4