trusty (3) pmTrimNameSpace.3.gz
NAME
pmTrimNameSpace - prune a performance metrics name space
C SYNOPSIS
#include <pcp/pmapi.h>
int pmTrimNameSpace(void);
cc ... -lpcp
DESCRIPTION
If the current Performance Metrics Application Programming Interface (PMAPI) context corresponds to a
version 1 archive log of Performance Co-Pilot (PCP) performance metrics (as collected by pmlogger(1)
-V1), then the currently loaded Performance Metrics Name Space (PMNS), is trimmed to exclude metrics for
which no description can be found in the archive. The PMNS is further trimmed to remove empty subtrees
that do not contain any performance metric.
Since PCP archives usually contain some subset of all metrics named in the default PMNS, pmTrimNameSpace
effectively trims the application's PMNS to contain only the names of the metrics in the archive.
Since PCP 2.0, pmTrimNameSpace is only needed for dealing with version 1 archives. Version 2 archives
actually store the "trimmed" PMNS.
Prior to any trimming, the PMNS is restored to the state as of the completion of the last
pmLoadASCIINameSpace(3) or pmLoadNameSpace(3), so the effects of consecutive calls to pmTrimNameSpace
with archive contexts are not additive.
If the current PMAPI context corresponds to a host and a pmLoadASCIINameSpace(3) or pmLoadNameSpace(3)
call was made, then the PMNS reverts to all names loaded into the PMNS at the completion of the last
pmLoadASCIINameSpace(3) or pmLoadNameSpace(3), i.e. any trimming is undone.
On success, pmTrimNameSpace returns zero.
SEE ALSO
pmlogger(1), PMAPI(3), pmLoadASCIINameSpace(3), pmLoadNameSpace(3), pmNewContext(3) and pmns(5).
DIAGNOSTICS
PM_ERR_NOPMNS
you must have loaded a PMNS using pmLoadASCIINameSpace(3) or pmLoadNameSpace(3) before calling
pmTrimNameSpace
PM_ERR_NOCONTEXT
the current PMAPI context is invalid