[collectd] warning on startup indeed happens

[Florian Forster]

Hi Florian,

On Sun, May 03, 2009 at 07:45:49AM +0200, Florian La Roche wrote:
> I'm running collectd-4.6.2 on CentOS-5.3. The source code suggests the
> following warning has happened only once, but it also shows up for my
> setup directly on bootup:
> 
> May  2 23:58:21 http collectd[1039]: rrdtool plugin: cache == NULL.
> May  2 23:58:22 http last message repeated 32 times
> 
> I used to see startup problems where collectd died right on bootup in
> the past, but the current version seems to run very stable.

the comment in the source code is probably a bit confusing. It's meant
to say that this condition is very unlikely to occur, but that it
occured at least once in the past (when I found and fixed that problem).

The problem occurs if the initialization function of the network plugin
is called before the initialization function of the rrdtool plugin. In
that case a network packet may be received and dispatched before the
rrdtool plugin is initialized (cache == NULL).

The daemon dying at startup sounds like exactly the problem that was
fixed here. An obscure fix for the warning would be to re-order the
`LoadPlugin' lines so the rrdtool plugin is above the network plugin.
This would also work around the crashes of previous versions, e. g. the
version included in Debian Lenny and the current 4.5.3.

I'll definitely pack a 4.5.4 before releasing 4.7.0, so that users of
the 4.5 line get another bugfix release before that line is abandoned.

Regards,
-octo
-- 
Florian octo Forster
Hacker in training
GnuPG: 0x91523C3D
http://verplant.org/
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: Digital signature
Url : http://mailman.verplant.org/pipermail/collectd/attachments/20090505/db7311d3/attachment.pgp