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):
Hostname to connect to.
Port number to use.
Username to run as and to connect to the database.
Password to connect to the database.
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.
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# ./Removepmdapostgresql 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.
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
This page is part of the PCP (Performance Co-Pilot) project.
Information about the project can be found at
⟨http://www.pcp.io/⟩. If you have a bug report for this manual
page, send it to firstname.lastname@example.org. This page was obtained from the
project's upstream Git repository
⟨https://github.com/performancecopilot/pcp.git⟩ on 2021-08-27.
(At that time, the date of the most recent commit that was found
in the repository was 2021-08-27.) If you discover any rendering
problems in this HTML version of the page, or you believe there
is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
Performance Co-Pilot PCP PMDAPOSTGRESQL(1)