Re: a PMDA using another PMDA

["Nathan Scott" <nathans@xxxxxxxxxxxxxxxxxxxxxxxx>]

hi,

On Jul 16, 12:40pm, gilly wrote:
> Subject: a PMDA using another PMDA
> Is it possible to write a PMDA which its metrics are accumulative metrics of
> another PMDA from other hosts? for example - a PMDA that calculates all RPC
> metrics of 5 hosts it monitors, therefore inside the 'total-RPC' PMDA
> there's a call to pmFetch for the rpc metrics (from linux PMDA) from the
> other hosts (the context is - PM_CONTEXT_HOST). Actually the call to
> 'pmFetch' for the accumulative metrics calls pmFetch for each host - for the
> calculated metrics.

Yes, that is possible.  In fact on IRIX & in pcp-pro there
is a configurable "summary" PMDA which used pmie(1) to do
just this sort of thing.

> Does it matter if the PMDA's are installed as DSO?

Do you mean in general or in this particular instance?  See
my mail to the list from the other day for some thoughts on
this topic.

cheers.

-- 
Nathan