PMDASYSTEMTAP(1)

NAME
pmdasystemtap - systemtap performance metrics domain agent (PMDA)

DESCRIPTION
pmdasystemtap is a Performance Metrics Domain Agent (PMDA) which exports metric values from the Linux systemtap dynamic tracing toolkit.

This implementation uses the stap(1) tool, which is a front-end to the systemtap toolkit.

INSTALLATION
In order to access performance data exported by systemtap from with PCP, it is necessary to perform two configuration steps.

Firstly, configure systemtap probes, and verify them with stap(1). These should be produced in a format that is easily parsed, and then stored in the $PCP_PMDAS_DIR/systemtap/probes.stp file.

Then pmdasystemtap must be configured to extract the values from the text produced by stap. Two example probes are implemented in the default systemtap PMDA script - readdir and sync traces (see $PCP_PMDAS_DIR/systemtap/pmdasystemtap.pl for details).

      # cd $PCP_PMDAS_DIR/systemtap
      # [ edit probes.stp, test /usr/bin/stap probes.stp ]
      # [ edit pmdasystemtap.pl ]

Once this is setup, you can access the names and values for the systemtap performance metrics by doing the following as root:

      # cd $PCP_PMDAS_DIR/systemtap
      # ./Install

To uninstall, do the following as root:

      # cd $PCP_PMDAS_DIR/systemtap
      # ./Remove

pmdasystemtap is launched by pmcd(1) and should never be executed directly. The Install and Remove scripts notify pmcd(1) when the agent is installed or removed.

FILES

$PCP_PMDAS_DIR/systemtap/probes.stp
    probe configuration file for stap(1), run by pmdasystemtap

$PCP_PMDAS_DIR/systemtap/Install
    installation script for the pmdasystemtap agent

$PCP_PMDAS_DIR/systemtap/Remove
    undo installation script for the pmdasystemtap agent

$PCP_LOG_DIR/pmcd/systemtap.log
    default log file for error messages from pmdasystemtap

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 configuration file, as described in pcp.conf(5).

SEE ALSO
PCPIntro(1), pmcd(1) and stap(1).