pcp
[Top] [All Lists]

Re: [pcp] RFC - pmlogrewrite

To: Ken McDonell <kenj@xxxxxxxxxxxxxxxx>
Subject: Re: [pcp] RFC - pmlogrewrite
From: Nathan Scott <nathans@xxxxxxxxxx>
Date: Fri, 9 Sep 2011 13:23:50 +1000 (EST)
Cc: pcp@xxxxxxxxxxx
In-reply-to: <1315441991.10496.10.camel@bozo-laptop>

----- Original Message -----
> The suggestion to split the proc metrics out of the linux pmda has
> raised the question (again) of controlled rewriting of PCP archives to
> handle changes in metadata over time.
> 
> pmlogextract cannot merge archives where the metadata is different for
> the same metric across the input archives, e.g. type changes from
> 32-bit
> to 64-bit with some PMDA upgrade, units change, or the name of a
> metric
> changes or the PMID of a metric changes (which is the problem with
> splitting the proc metrics out of the linux PMDA).
> 
> The proposed solution is to create pmlogrewrite and then allow
> pmlogextract to preprocess all input archives with pmlogwrite before
> merging.
> 
> Of course pmlogrewrite could be used stand alone as well.
> 
> The changes to be made by pmlogrewrite are defined in a control file
> that would be something like the attached strawman syntax proposal.
> 
> I'd be interested in comments/feedback. For example, I'm not convinced
> of the usefulness of the "new" instance specification.
> 

Looks good.  Might want to add renaming a metric (name1 -> name2).
Yeah, not sure I've ever had a need for adding a "new" instance.
Could probably replace pmloglabel with this too (make a wrapper?).

cheers.

-- 
Nathan

<Prev in Thread] Current Thread [Next in Thread>