[pcp] Derived Metrics and pmlogsummary.. ? Is it supposed to work?
nathans at aconex.com
Thu Sep 8 01:57:31 CDT 2011
----- Original Message -----
> Why wouldn't it work in pmlogsummary?
I suspect its to do with the way pmlogsummary is using a
fairly low level interface (see pmFetchArchive(3)) to scan
through every data point in the archive with no changes (ie.
no interpolation, rate conversion, etc) ... this scanning
is all done upfront before we look at the requested metrics
at all. Ken might have a cunning plan to resolve this, but
I suspect it wont be easy unfortunately.
Might be worth considering alongside that other missing piece
of log summary functionality - calculating the Nth percentile.
That also would need some design-level surgery for logsummary,
though probably they are orthogonal.
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