Re: questions/suggestion "RAM-only" log support in sysklogd?

Hi!

guy keren wrote:
> i was looking for a way to have some log messages (mostly debug
> messages, that i don't want to flood the disk normally) be stored in
> a cyclic memory buffer, instead of logged into a file - and only
> have this buffer dumped to disk upon demand (e.g. when there is a
> problem that requires debugging).

I don't know of such a feature.

However, using a named pipe and attaching a postprocessing process
(e.g. Perl or Python script) you should easily be able to achieve this
feature.

> i was wondering if a patch that adds such support is available
> anywhere, or if it will be considered for inclusion in sysklogd if
> provided.

Such a patch would at least be stored in the contrib area so that
other users can make use of it as well. Your patch would be
appreciated in any case.

> the motivation is being able to debug various problems with various
> software components the first time around - instead of having to
> re-produce them with higher debug levels - and yet without filling
> the disk with lots of junk and without causing too much disk
> activity when there's no need to look at these logs.

You could dump log messages to a solid state device or a file in tmpfs
to avoid disk activity as well.

> note: we did consider simply placing certain log files in a RAM disk
> - but we then we'll need to handle the creation of this RAM disk,
> very often logrotate (to avoid having it fill up), etc - and it
> seems like a more awkward solution, and less robust in case of a
> sudden log-flood.

You could combine the ram disk with a named pipe and a process that
flushes log messages to the ram disk after a certain amount of
messages have accumulated.

I believe you could solve your problem with a named pipe and a
post-processing script. I would be glad to place such a script to the
contrib area as well.

Regards,

        Joey

-- 
All language designers are arrogant.  Goes with the territory...
	-- Larry Wall