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:

1.

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.

2.

Configure pmdasystemtap 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

If you want to undo the installation, 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