Re: Multi-Volume Archive + Live Data Playback for PCP Client Tools

["Frank Ch. Eigler" <fche@xxxxxxxxxx>]

Hi, Ken -


> [...] by "metadata differences" I mean a metric that appears in more
> than one archive and has some difference in the pmDesc data that
> describes that metric or the associated PMNS fragment that maps a
> name to a PMID ... this means - name [...]

One glitch with that could be PMDAs whose PMNS is dynamic from run to
run (like the papi pmda, which is almost able to be used as a logged
data source).  The name-to-PMID mapping may vary there (as new PAPI
versions come, or host CPU changes, new counters(=metrics) may appear
in some odd sequence, so get scrambled PMIDs), but the name & pmDesc
(semantics etc.) would remain the same and previous values comparable.

I don't know how pervasive this situation would be, but if it's not
too hard to support, we should.  (e.g., we could track metrics across
archives by name rather than pmid.)

- FChE