pmdamysql — MySQL and MariaDB database PMDA
Description
pmdamysql is a Performance Co-Pilot PMDA which extracts live performance data from a running MySQL or MariaDB database.
Installation
pmdamysql uses a configuration file from (in this order):
- /etc/pcpdbi.conf
-
$PCP_PMDAS_DIR/mysql/mysql.conf
This file can contain overridden values (Perl code) for the settings listed at the start of pmdamysql.pl, namely:
- database name (see DBI(3) for details, default is "DBI:mysql:mysql")
- database username (default is "dbmonitor")
- database password (default is "dbmonitor")
- login account (default is "pcp")
On some versions of MariaDB (10+) the performance schema is disabled by default, and must be enabled for the PMDA to function. This is achieved by adding the string "performance_schema" into the "[mysqld]" section of the MariaDB configuration file (either my.cnf or my.ini). The "SHOW ENGINES" SQL statement shows support for the performance schema.
Once these initial setup actions are complete, you can access the names and values for the mysql performance metrics by doing the following as root:
# cd $PCP_PMDAS_DIR/mysql
# ./Install
To uninstall, do the following as root:
# cd $PCP_PMDAS_DIR/mysql
# ./Remove
pmdamysql 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.
Binary Status values in text
Some of the status values are in the form of YES/NO or ON/OFF.
Since these cannot be interpreted by tools like pmie(1), they have been duplicated with a _num extension and the values of 1 (YES/ON) or 0 (NO/OFF).
Eg
- mysql.slave_status.slave_io_running
- mysql.slave_status.slave_io_running_num
Files
- /etc/pcpdbi.conf
configuration file for all PCP database monitors
-
$PCP_PMDAS_DIR/mysql/mysql.conf configuration file for pmdamysql
- $PCP_PMDAS_DIR/mysql/Install
installation script for the pmdamysql agent
- $PCP_PMDAS_DIR/mysql/Remove
undo installation script for the pmdamysql agent
- $PCP_LOG_DIR/pmcd/mysql.log
default log file for error messages from pmdamysql
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), pmdadbping(1), pmie(1) and DBI(3).