NAME

       pmFetchArchive - get performance metrics directly from a set if archive logs

C SYNOPSIS

       #include <pcp/pmapi.h>

       int pmFetchArchive(pmResult **result);

       cc ... -lpcp

DESCRIPTION

       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

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

DIAGNOSTICS

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