pmFetchArchive(3) — Linux manual page


PMFETCHARCHIVE(3)         Library Functions Manual         PMFETCHARCHIVE(3)

NAME         top

       pmFetchArchive  -  get performance metrics directly from a set if ar‐
       chive logs

C SYNOPSIS         top

       #include <pcp/pmapi.h>

       int pmFetchArchive(pmResult **result);

       cc ... -lpcp

DESCRIPTION         top

       pmFetchArchive is a variant of pmFetch(3) that may only be used when
       the current Performance Metrics Application Programming Interface
       (PMAPI) context is associated with a set of archive logs.

       The result is instantiated with all of the metrics (and instances)
       from the next archive record, consequently there is no notion of a
       list of desired metrics, and the instance profile of the PMAPI
       context is ignored.

       pmFetchArchive may return a result in which numpmid is zero.  This is
       a <mark> record that indicates a temporal discontinuity in the time
       series of performance metrics.  This can happen at the boundary
       between archive logs in a set or if the archive log associated with
       the current PMAPI context was created using pmlogextract(1) to
       concatenate two or more PCP archive logs, and the <mark> record marks
       a point in time between the end of one input archive and the start of
       the next input archive.

       It is expected that pmFetchArchive would be used to create utilities
       that scan sets of archive logs, while the more common access to the
       archives would be via the pmFetch(3) interface.

       To skip records within the set of archive logs, use pmSetMode(3) to
       change the collection time within the current PMAPI context, then
       call pmFetchArchive.

       Note that the result returned by pmFetchArchive is dynamically
       allocated, and must be released using pmFreeResult(3), not free(3).
       See pmFetch(3) and pmFreeResult(3) for further details.

       pmFetchArchive returns zero on success.

SEE ALSO         top

       PMAPI(3), pmFetch(3), pmFreeResult(3), pmNewContext(3), pmSetMode(3)
       and pmTrimNameSpace(3).

DIAGNOSTICS         top

              the current PMAPI context is not associated with a set of
              archive logs

COLOPHON         top

       This page is part of the PCP (Performance Co-Pilot) project.
       Information about the project can be found at ⟨⟩.
       If you have a bug report for this manual page, send it to  This page was obtained from the project's upstream
       Git repository ⟨⟩ on
       2020-11-01.  (At that time, the date of the most recent commit that
       was found in the repository was 2020-10-30.)  If you discover any
       rendering problems in this HTML version of the page, or you believe
       there is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to

Performance Co-Pilot                 PCP                   PMFETCHARCHIVE(3)

Pages that refer to this page: pcpintro(3)PCPIntro(3)pmfetch(3)pmFetch(3)pmgetarchiveend(3)pmGetArchiveEnd(3)pmregisterderived(3)pmRegisterDerived(3)pmRegisterDerivedMetric(3)pmsetmode(3)pmSetMode(3)