[collectd] snmp plugin and "Table true" in 4.4.1

[Sebastian Harl]

Hi,

On Wed, Oct 01, 2008 at 10:40:19AM +0200, Florian Forster wrote:
> On Thu, Aug 28, 2008 at 01:13:15PM +0500, Sergey wrote:
> > What do you think about InstanceRewrite feature ? For example, by
> > regular expression.
> 
> sounds good. The regexec(3) library function can return match offsets.
> Those can be used to replace matching parts in a string. Do you want to
> take a shot?

I would not implement that on a per plugin level but rather use the
"filter" mechanism that I have in mind. Unfortunately, I did not have
the time to write something down about that or even implement it so far
:-/

The very basic idea is to introduce another type of callback which is in
fact very similar to a write callback:

  int (*) (const data_set_t *, value_list_t *)

(note that the value list is not const)

The return value of that callback should indicate what further actions
are to be taken by the daemon (e.g. ignore the value, use it for
threshold checking only, dispatch it to write callbacks only, etc. ...
just some first ideas). If more than one filter callback is in use, one
could think about "consolidating" the return values - but we should keep
it simple for now and do that in a second step.

Now, this type of callback could be used for the following purposes:

 * rewrite information included in the value list (e.g. the instance
   name)

 * discard certain information on a fine-grained level based on the
   information provided by the data set and value list

Any further ideas? Comments?

Cheers,
Sebastian

-- 
Sebastian "tokkee" Harl +++ GnuPG-ID: 0x8501C7FC +++ http://tokkee.org/

Those who would give up Essential Liberty to purchase a little Temporary
Safety, deserve neither Liberty nor Safety.         -- Benjamin Franklin

-------------- 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/20081001/2eb7c40f/attachment.pgp