NAME

       pmdapostgresql - PostgreSQL database PMDA

DESCRIPTION

       pmdapostgresql  is a Performance Co-Pilot PMDA which extracts live performance data from a
       running PostgreSQL database.

       Many of the staticstics available from a PostgreSQL server may not be enabled by  default.
       Refer            to            the            online            documentation           at
       https://www.postgresql.org/docs/current/static/monitoring-stats.html which describes  each
       of the available parameters related to statistics collection and how to enable them.

INSTALLATION

       pmdapostgresql uses a configuration file from (in this order):
       •   /etc/pcpdbi.conf
       •   $PCP_PMDAS_DIR/postgresql/postgresql.conf
       •   ./postgresql.conf

       This  file  can contain overridden values (Perl code) for the settings listed at the start
       of pmdapostgresql.pl, for example:
       •   $database   -    database    access    method    and    database    name,    [default:
           'dbi:Pg:dbname=postgres'] (see DBI(3) for details)
       •   $username - username to connect to the database [default: 'postgres']
       •   $password - password to connect to the database [default: '']
       •   $os_user - operating system username (PMDA will run with the corresponding user id, if
           invoked as root) [default: $username]

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

             # cd $PCP_PMDAS_DIR/postgresql
             # ./Install

       To uninstall, do the following 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  it's
       connection  is  lost  -  e.g.  if  the  postgresql  service  is  restarted.   In addition,
       pmdapostgresql will disconnect if it is sent a SIGUSR1 signal, and will  then  attempt  to
       reconnect  on the next fetch.  This is mostly for quality assurance and test purposes, but
       may be useful in other circumstances.

SUPPORTED VERSIONS

       pmdapostgresql has been tested and verified with  postgresql  server,  version  9.6.7  and
       earlier.   The  verification was done using the pgbench(1) utility.  It has not (yet) been
       tested or verified with postgresql version 10.x.

FILES

       /etc/pcpdbi.conf
           configuration file for all PCP database monitors
       $PCP_PMDAS_DIR/postgresql/postgresql.conf
           configuration file for pmdapostgresql
       $PCP_PMDAS_DIR/postgresql/Install
           installation script for the pmdapostgresql agent
       $PCP_PMDAS_DIR/postgresql/Remove
           undo installation script for the pmdapostgresql agent
       $PCP_LOG_DIR/pmcd/postgresql.log
           default log file for error messages from pmdapostgresql

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), pmdadbping(1) and DBI(3).