PMM supports all commonly used variants of MySQL, including Percona Server, MariaDB, and Amazon RDS. To prevent data loss and performance issues, PMM does not automatically change MySQL configuration. However, there are certain recommended settings that help maximize monitoring efficiency. These recommendations depend on the variant and version of MySQL you are using, and mostly apply to very high loads.
PMM can collect query data either from the slow query log or from Performance Schema. The slow query log provides maximum details, but can impact performance on heavily loaded systems. On Percona Server the query sampling feature may reduce the performance impact.
Performance Schema is generally better for recent versions of other MySQL variants. For older MySQL variants, which have neither sampling, nor Performance Schema, configure logging only slow queries.
MySQL with too many tables can lead to PMM Server overload due to the
streaming of too much time series data. It can also lead to too many queries
mysqld_exporter causing extra load on MySQL. Therefore PMM Server
disables most consuming
mysqld_exporter collectors automatically if
there are more than 1000 tables.
You can add configuration examples provided below to
restart the server or change variables dynamically using the following syntax:
SET GLOBAL <var_name>=<var_value>
The following sample configurations can be used depending on the variant and version of MySQL:
If you are running Percona Server (or XtraDB Cluster), configure the slow query log to capture all queries and enable sampling. This will provide the most amount of information with the lowest overhead.
log_output=file slow_query_log=ON long_query_time=0 log_slow_rate_limit=100 log_slow_rate_type=query log_slow_verbosity=full log_slow_admin_statements=ON log_slow_slave_statements=ON slow_query_log_always_write_time=1 slow_query_log_use_global_control=all innodb_monitor_enable=all userstat=1
If you are running MySQL 5.6+ or MariaDB 10.0+, see Configuring Performance Schema.
If you are running MySQL 5.5 or MariaDB 5.5, configure logging only slow queries to avoid high performance overhead.
log_output=file slow_query_log=ON long_query_time=0 log_slow_admin_statements=ON log_slow_slave_statements=ON
This may affect the quality of monitoring data gathered by Query Analytics.
Creating a MySQL User Account for PMM¶
When adding a MySQL instance to monitoring, you can specify the MySQL server superuser account credentials. However, monitoring with the superuser account is not advised. It’s better to create a user with only the necessary privileges for collecting data.
As an example, the user
pmm can be created manually with the necessary
privileges and pass its credentials when adding the instance.
To enable complete MySQL instance monitoring, a command similar to the following is recommended:
sudo pmm-admin add mysql --username pmm --password <password>
Of course this user should have necessary privileges for collecting data. If
pmm user already exists, you can grant the required privileges as
CREATE USER 'pmm'@'localhost' IDENTIFIED BY 'pass' WITH MAX_USER_CONNECTIONS 10; GRANT SELECT, PROCESS, SUPER, REPLICATION CLIENT, RELOAD ON *.* TO 'pmm'@'localhost';