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pmgetarchivelabel(3) [centos man page]

PMGETARCHIVELABEL(3)					     Library Functions Manual					      PMGETARCHIVELABEL(3)

NAME
pmGetArchiveLabel - fetch the label record from a performance metrics archive log C SYNOPSIS
#include <pcp/pmapi.h> int pmGetArchiveLabel(pmLogLabel *lp); cc ... -lpcp DESCRIPTION
Within the framework of the Performance Co-Pilot (PCP), archive logs of performance metrics values may be accumulated and saved using the program pmlogger(1). The routine pmGetArchiveLabel may be used to fetch the label record from an archive log that has already been opened using pmNewContext(3), or pmDupContext(3), and thereby associated with the current Performance Metrics Application Programming Interface (PMAPI) context. The result returned via the pointer lp is a structure that must be pre-allocated by the caller and has the following format (defined in pmapi.h). /* * Label Record at the start of every log file */ typedef struct { int ll_magic; /* PM_LOG_MAGIC | log format version no. */ pid_t ll_pid; /* PID of logger */ struct timeval ll_start;/* start of this log */ char ll_hostname[PM_LOG_MAXHOSTLEN]; /* name of collection host */ char ll_tz[40]; /* $TZ at collection host */ } pmLogLabel; For an application, the most useful information from the archive label is likely to be in the fields ll_start, ll_hostname or ll_tz. Note that the size of the ll_hostname field is PM_LOG_MAXHOSTLEN (64 bytes) which is less than MAXHOSTNAMELEN (see gethostbyname(3)) on some platforms. These semantics are necessary to retain backwards compatibility with the PCP archive file format. pmGetArchiveLabel returns zero for success. PCP ENVIRONMENT
Environment variables with the prefix PCP_ are used to parameterize the file and directory names used by PCP. On each installation, the file /etc/pcp.conf contains the local values for these variables. The $PCP_CONF variable may be used to specify an alternative configura- tion file, as described in pcp.conf(5). Values for these variables may be obtained programmatically using the pmGetConfig(3) function. SEE ALSO
pmlogger(1), PMAPI(3), pmDupContext(3), pmGetConfig(3), pmNewContext(3), pcp.conf(5) and pcp.env(5). DIAGNOSTICS
PM_ERR_NOCONTEXT the current PMAPI context is either invalid, or not associated with an archive log Performance Co-Pilot PCP PMGETARCHIVELABEL(3)

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PMTRIMNAMESPACE(3)					     Library Functions Manual						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 applica- tion'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 Performance Co-Pilot PCP PMTRIMNAMESPACE(3)
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