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)

Check Out this Related Man Page

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)

Linux and UNIX Man Pages

pmgetarchivelabel(3) [centos man page]

Check Out this Related Man Page