Re: [pcp] Calculated/derived metrics?

[Ken McDonell <kenj@xxxxxxxxxxxxxxxx>]

On 04/05/15 18:18, Marko Myllynen wrote:
> ...
> I think it would still be interesting to hear experiences around this,
> if calculated/derived metrics are needed in some cases, how to get them
> most efficiently?
Marko,

There is already a pretty complete derived metrics implementation.

It uses a configuration file to define the expressions for the derived 
metrics and assign names to them, then the implementation sits in the 
data path so that all PMAPI calls for metadata or metric values are 
translated appropriately.
Refer to pmRegisterDerived(3) for the expression syntax. PCPIntro(1) 
describes the environment variable $PCP_DERIVED_CONFIG that needs to be 
set to pathname to a file containing the definitions of the derived 
metrics in form needed by pmLoadDerivedConfig(3).
If this does not address your needs I'd be keen to hear how and why.

Cheers, Ken.