SIMPLE SOLUTIONS

PMGETARCHIVELABEL(3) - man page online | library functions

Fetch the label record from a performance metrics archive log.

Chapter
PCP
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 met‐ rics 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 asso‐ ciated with the current Performance Metrics Application Programming Interface (PMAPI) con‐ text. 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 neces‐ sary 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 config‐ uration 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)
This manual Reference Other manuals
pmGetArchiveLabel(3) referred by pmGetArchiveEnd(3) | pmGetContextHostName(3) | __pmParseTime(3) | pmParseTimeWindow(3)
refer to gethostbyname(3) | pcp.conf(5) | pcp.env(5) | PMAPI(3) | pmDupContext(3) | pmGetConfig(3) | pmlogger(1) | pmNewContext(3)