PMTRIMNAMESPACE(3)

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