Re: pmlogger: fetch.c: changed & PMCD_ADD_AGENT:

[Dave Brolley <brolley@xxxxxxxxxx>]

On 06/21/2016 03:19 AM, Ken McDonell wrote:
> > -----Original Message-----
> > From: Dave Brolley [mailto:brolley@xxxxxxxxxx]
> >
> >
> > 1.      I'm looking at the code in src/pmlogger/src/fetch.c where 'if
> > (changed & PMCD_ADD_AGENT)' is handled. It seems to me that this test
> > which adds a mark record in the case a pmda (re)starts (outside the
> > loop which handles the received pdus) is too late, since pdus
> > representing several potentially changed/reset metrics may have been
> > erroneously logged before then. Should the test not be made, and the
> > mark record not be generated inside the loop at the point at which the
> > change is first noticed?
> I think the code is wrong.
>
> The protocol is ...
> -> client send request
> <- pmcd sends error pdu with error code > 0 AND
> <- pmcd sends response pdu
>
> So __pmGetPDU loop in fetch.c gets and decodes these in the correct order, but 
> the test and putmark() call should be inside the loop before the pmResult is 
> output.
Hmmmm. I may have jumped the gun. The loop (in myFetch) exists only to 
handle the case that both the error PDU (with error code >0) and the 
response pdu are sent. Nothing is written until myFetch returns to the 
caller (do_work in callback.c).
So I think all that I need to ensure is that the metrics are validated 
before any <mark> record is generated. This can be done outside the 
loop. I've pushed my code to
git://git.pcp.io/brolley/pcp pmlogger-pmda-reconnect

Dave