pmdapostgresql(1) — Linux manual page


PMDAPOSTGRESQL(1)        General Commands Manual       PMDAPOSTGRESQL(1)

NAME         top

       pmdapostgresql - PostgreSQL database PMDA

DESCRIPTION         top

       pmdapostgresql is a Performance Co-Pilot (PCP) Performance
       Metrics Domain Agent (PMDA) which extracts live performance data
       from a running PostgreSQL database server.

       Many of the statistics available from a PostgreSQL server may not
       be enabled by default.  Refer to the online documentation 
       which describes each of the available parameters related to
       statistics collection and how to enable them.


       pmdapostgresql reads a mandatory ini-style configuration file:


       This file currently contains only one section [authentication]
       which specifies values for the following settings (their default
       values are shown in parenthesis):

       host (local)
              Hostname to connect to.

       port (5432)
              Port number to use.

       dbname (postgres)
              Database name.

       username (postgres)
              Username to run as and to connect to the database.

       password (password)
              Password to connect to the database.

       osuser (unset)
              Operating system user the PMDA runs as.

       The defaults (as above) will result in the PMDA running as the
       current user, using a UNIX domain socket connection to the
       PostgreSQL server on the localhost.

       If osuser is not specified in the configuration file, the PMDA
       will run as the current user.  A host specification of local will
       use a UNIX domain socket, which uses peer authentication, see
       comments in the pg_hba.conf file.  In this case, the osuser
       setting should probably be set to postgres.

       It is generally not necessary to alter the default configuration
       file for monitoring the local PostgreSQL server instance with a
       default server configuration.  Note that the port number is
       required even for a UNIX domain connection because it's used as
       the socket filename by the server.

INSTALLATION         top

       To install, the following must be done as root:

           # cd $PCP_PMDAS_DIR/postgresql
           # ./Install

       To uninstall, the following must be done as root:

           # cd $PCP_PMDAS_DIR/postgresql
           # ./Remove

       pmdapostgresql 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.

       pmdapostgresql will automatically attempt to reconnect to the
       PostgreSQL server if its connection is lost - e.g. if the
       PostgreSQL service is restarted.


       This version of pmdapostgresql has been tested and verified with
       PostgreSQL server version 10.2 and earlier.  Later versions will
       probably also work correctly because the PMDA probes the various
       performance tables on start-up to determine the column ordering.
       It also tolerates missing or renamed tables and/or columns.

FILES         top

            configuration file for the pmdapostgresql agent

            installation script for the pmdapostgresql agent

            undo installation script for the pmdapostgresql agent

            default log file for messages from the pmdapostgresql agent

       Note that the usual/default value for $PCP_PMDAS_DIR is
       /var/lib/pcp/pmdas and the default for $PCP_LOG_DIR is
       /var/log/pcp but these settings are platform dependent.


       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

SEE ALSO         top

       PCPIntro(1), pmcd(1) and .

COLOPHON         top

       This page is part of the PCP (Performance Co-Pilot) project.
       Information about the project can be found at 
       ⟨⟩.  If you have a bug report for this manual
       page, send it to  This page was obtained from the
       project's upstream Git repository
       ⟨⟩ on 2023-12-22.
       (At that time, the date of the most recent commit that was found
       in the repository was 2023-12-16.)  If you discover any rendering
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       (which is not part of the original manual page), send a mail to

Performance Co-Pilot               PCP                 PMDAPOSTGRESQL(1)