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pmfetcharchive(3) — Linux manual page

PMFETCHARCHIVE(3)        Library Functions ManualPMFETCHARCHIVE(3)

NAME        top

pmFetchArchive, - get performance metric values directly from       archives

C SYNOPSIS        top

#include <pcp/pmapi.h>int pmFetchArchive(pmResult **result);cc ... -lpcp

DESCRIPTION        top

       ThepmFetchArchiveAPI  is a variant of thepmFetch(3) interface       that may only be used when the current Performance Metrics  Appli‐       cation  Programming Interface (PMAPI) context is associated with a       set of archives.       Theresult 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.pmFetchArchivemay return aresult in whichnumpmid is zero.  This       is  a<mark> record that indicates a temporal discontinuity in the       time series of performance metrics.  This can happen at the bound‐       ary between archives in a set or if the  archive  associated  with       the  current  PMAPI  context  was created usingpmlogextract(1) to       concatenate two or more PCP archives, 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 thatpmFetchArchivewill be used to create utili‐       ties that scan sets of archives, while the more common  access  to       the archives would be via thepmFetchinterface.       To  skip  records  within the set of archives, usepmSetMode(3) to       change the collection time within the current PMAPI context,  then       call eitherpmFetchArchive       Note that theresult returned bypmFetchArchiveis dynamically al‐       located,  and  must  be  released  usingpmFreeResult(3), but notfree(3).  SeepmFetch(3), andpmFreeResult(3) for further details.pmFetchArchivereturns zero on success.

DIAGNOSTICS        top

PM_ERR_NOTARCHIVE              the current PMAPI context is not associated with a set of              archives

COMPATIBILITY        top

       Prior to PCP 7.0 thetimestamp field in the pmResult struct was a       struct timeval.  To support PMAPI transition, the old interface       and semantics can be used if applications are recompiled with-DPMAPI_VERSION=2.       For a time in PCP 6.x there was a routine with the same semantics       as the currentpmFetchArchivecalledpmFetchHighResArchive, and a       struct with the same definition as the current pmResult struct       called pmResultHighRes, although both are now deprecated and com‐       pile-time support forpmFetchHighResArchiveand pmResultHighRes       will be removed in a future release.

SEE ALSO        top

PMAPI(3),pmFetch(3),pmFreeResult(3),pmNewContext(3),pmSetMode(3) andpmTrimNameSpace(3).

COLOPHON        top

       This page is part of thePCP (Performance Co-Pilot) project.  In‐       formation about the project can be found at ⟨http://www.pcp.io/⟩.       If you have a bug report for this manual page, send it to       pcp@groups.io.  This page was obtained from the project's upstream       Git repository ⟨https://github.com/performancecopilot/pcp.git⟩ on       2025-08-11.  (At that time, the date of the most recent commit       that was found in the repository was 2025-08-11.)  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 isnot part of the original manual page), send a       mail to man-pages@man7.orgPerformance Co-Pilot               PCPPMFETCHARCHIVE(3)

Pages that refer to this page:pcpintro(3), pmfetch(3), pmgetarchiveend(3), pmregisterderived(3), pmsetmode(3)

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