Location: Roanoke Department: Network Support
Per Ken McDowell :
>Assuming the archives are all collected from the same host ...
>
> The semantics of the archives (and in particular the meta data
> therein) make it difficult for a tool to process chronologically
> adjacent (or even overlapping) archives. Rather it is better to
> stitch the archives together with pmlogextract(1) and then point the
> tool at the single resultant archive.
>
>If the archives are collected from different hosts then you have a
>different set of curly issues.
Regarding the nature of the archives making the processing of spanned archives
difficult ...
That's too bad. Other performance products are designed to provide for a
"log-once - read-many" approach which does not require any re-processing of logs
in order to select a particular range of dates/times for a particular host
computer. After reviewing the man page for pmlogextract, I can agree that
several logs for a given host can be re-processed to create a single archive
file for analysis. The utility also offers an opportunity for data reduction
through selection of a sub-set of metrics for inclusion in the output archive.
Obviously, I'd prefer to avoid this type of re-processing to obtain the data
desired when the archive file names and the content of the archives already
communicate the information necessary to support the desired date/time selection
criteria.
Regarding the question of multiple nodes ...
I agree that it is a significant design consideration. However, it may not be
too early for the project to start thinking about a design that will facilitate
multi-node reporting. When one considers the evolving use of clustered machines,
the reporting requirement for those environments is to reflect the over-all
performance and capacity measurements for the cluster as a whole. If PCP is to
be useful in those environments, it will have to accommodate this requirement.
BTW: Does pmlogextract support a wild-carded input file specification ?
Thanks !
Cameron
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