MySQL / MariaDB

Auto-Detection

Built-in Metrics

Logs

MySQL and MariaDB are widely used open-source relational database management systems.

Auto-Detection

Glouton detects MySQL and MariaDB by their process and listening port (default: 3306).

To enable metrics gathering, credentials are required. Glouton finds them automatically if:

MySQL or MariaDB and the agent are running on Ubuntu or Debian
MySQL or MariaDB is running in a Docker container with the root password set through the environment variable MYSQL_ROOT_PASSWORD or MARIADB_ROOT_PASSWORD

If auto-detected parameters are incorrect, override them manually:

Linux
Windows

sudo tee /etc/glouton/conf.d/99-mysql.conf > /dev/null << 'EOF'
service:
  # For a MySQL or MariaDB running outside a container
  - type: "mysql"
    username: "USERNAME"
    password: "PASSWORD"
    address: "127.0.0.1"
    # If set to an existing socket file, Glouton will prefer the Unix socket
    # for gathering metrics. Service check will continue to use the TCP address.
    metrics_unix_socket: "/var/run/mysqld/mysqld.sock"
    port: 3306

  # For an additional MySQL or MariaDB running outside a container
  - type: "mysql"
    instance: "NAME_ASSOCIATED_WITH_YOUR_ADDITIONAL_SERVICE"
    username: "USERNAME"
    password: "PASSWORD"
    address: "127.0.0.1"
    metrics_unix_socket: "/var/run/mysqld/mysqld2.sock"
    port: 3307

  # For a MySQL or MariaDB running in a Docker container
  - type: "mysql"
    instance: "CONTAINER_NAME"
    username: "USERNAME"
    password: "PASSWORD"
    address: "172.17.0.2"
    port: 3306
EOF

Create or edit C:\ProgramData\glouton\conf.d\99-mysql.conf:

service:
  # For a MySQL or MariaDB running outside a container
  - type: "mysql"
    username: "USERNAME"
    password: "PASSWORD"
    address: "127.0.0.1"
    port: 3306

  # For an additional MySQL or MariaDB running outside a container
  - type: "mysql"
    instance: "NAME_ASSOCIATED_WITH_YOUR_ADDITIONAL_SERVICE"
    username: "USERNAME"
    password: "PASSWORD"
    address: "127.0.0.1"
    port: 3307

Glouton automatically detects configuration changes.

Built-in Metrics

Metric	Description
`service_status`	Status of MySQL or MariaDB
`mysql_cache_result_qcache_hits`	Number of query cache hits per second
`mysql_cache_result_qcache_inserts`	Number of queries added to the query cache per second
`mysql_cache_result_qcache_not_cached`	Number of uncacheable queries per second
`mysql_cache_result_qcache_prunes`	Number of queries deleted from the query cache due to low memory per second
`mysql_cache_blocksize_qcache`	Number of blocks in the query cache
`mysql_cache_free_blocks`	Number of free memory blocks in the query cache
`mysql_cache_free_memory`	Free memory for the query cache in bytes
`mysql_cache_size_qcache`	Number of queries registered in the query cache
`mysql_locks_immediate`	Number of table locks granted immediately per second
`mysql_locks_waited`	Number of table locks that required waiting per second
`mysql_innodb_history_list_len`	Size of the InnoDB transaction history list
`mysql_innodb_locked_transaction`	Number of currently locked InnoDB transactions
`mysql_octets_rx`	Network traffic received from clients in bytes per second
`mysql_octets_tx`	Network traffic sent to clients in bytes per second
`mysql_queries`	Number of queries per second
`mysql_slow_queries`	Number of slow queries per second
`mysql_threads_cached`	Number of threads in the thread cache
`mysql_threads_connected`	Number of currently open connections
`mysql_threads_running`	Number of threads that are not sleeping
`mysql_total_threads_created`	Number of threads created per second
`mysql_commands_begin`	Number of "BEGIN" statements executed per second
`mysql_commands_binlog`	Number of "BINLOG" statements executed per second
`mysql_commands_call_procedure`	Number of "CALL PROCEDURE" statements executed per second
`mysql_commands_change_master`	Number of "CHANGE MASTER" statements executed per second
`mysql_commands_change_repl_filter`	Number of "CHANGE REPL FILTER" statements executed per second
`mysql_commands_check`	Number of "CHECK TABLE" statements executed per second
`mysql_commands_checksum`	Number of "CHECKSUM TABLE" statements executed per second
`mysql_commands_commit`	Number of "COMMIT" statements executed per second
`mysql_commands_dealloc_sql`	Number of "DEALLOCATE PREPARE" statements executed per second
`mysql_commands_stmt_close`	Number of "DEALLOCATE PREPARE" statements executed per second
`mysql_commands_delete_multi`	Number of multi-table "DELETE" statements executed per second
`mysql_commands_delete`	Number of "DELETE" statements executed per second
`mysql_commands_do`	Number of "DO" statements executed per second
`mysql_commands_execute_sql`	Number of "EXECUTE" statements executed per second
`mysql_commands_stmt_execute`	Number of "EXECUTE" statements executed per second
`mysql_commands_explain_other`	Number of "EXPLAIN FOR CONNECTION" statements executed per second
`mysql_commands_flush`	Number of "FLUSH" statements executed per second
`mysql_commands_ha_close`	Number of "HA CLOSE" statements executed per second
`mysql_commands_ha_open`	Number of "HA OPEN" statements executed per second
`mysql_commands_ha_read`	Number of "HA READ" statements executed per second
`mysql_commands_insert_select`	Number of "INSERT ... SELECT" statements executed per second
`mysql_commands_insert`	Number of "INSERT" statements executed per second
`mysql_commands_kill`	Number of "KILL" statements executed per second
`mysql_commands_preload_keys`	Number of "LOAD INDEX INTO CACHE" statements executed per second
`mysql_commands_load`	Number of "LOAD" statements executed per second
`mysql_commands_lock_tables`	Number of "LOCK TABLES" statements executed per second
`mysql_commands_optimize`	Number of "OPTIMIZE" statements executed per second
`mysql_commands_prepare_sql`	Number of "PREPARE" statements executed per second
`mysql_commands_stmt_prepare`	Number of "PREPARE" statements executed per second
`mysql_commands_purge_before_date`	Number of "PURGE BEFORE DATE" statements executed per second
`mysql_commands_purge`	Number of "PURGE" statements executed per second
`mysql_commands_release_savepoint`	Number of "RELEASE SAVEPOINT" statements executed per second
`mysql_commands_repair`	Number of "REPAIR" statements executed per second
`mysql_commands_replace_select`	Number of "REPLACE SELECT" statements executed per second
`mysql_commands_replace`	Number of "REPLACE" statements executed per second
`mysql_commands_reset`	Number of "RESET" statements executed per second
`mysql_commands_resignal`	Number of "RESIGNAL" statements executed per second
`mysql_commands_rollback_to_savepoint`	Number of "ROLLBACK TO SAVEPOINT" statements executed per second
`mysql_commands_rollback`	Number of "ROLLBACK" statements executed per second
`mysql_commands_savepoint`	Number of "SAVEPOINT" statements executed per second
`mysql_commands_select`	Number of "SELECT" statements executed per second
`mysql_commands_signal`	Number of "SIGNAL" statements executed per second
`mysql_commands_slave_start`	Number of "START SLAVE" statements executed per second
`mysql_commands_group_replication_start`	Number of "START" for group replication statements executed per second
`mysql_commands_stmt_fetch`	Number of "STMT FETCH" statements executed per second
`mysql_commands_stmt_reprepare`	Number of "STMT REPREPARE" statements executed per second
`mysql_commands_stmt_reset`	Number of "STMT RESET" statements executed per second
`mysql_commands_stmt_send_long_data`	Number of "STMT SEND LONG DATA" statements executed per second
`mysql_commands_slave_stop`	Number of "STOP SLAVE" statements executed per second
`mysql_commands_group_replication_stop`	Number of "STOP" for group replication statements executed per second
`mysql_commands_truncate`	Number of "TRUNCATE" statements executed per second
`mysql_commands_unlock_tables`	Number of "UNLOCK TABLES" statements executed per second
`mysql_commands_update_multi`	Number of multi-table "UPDATE" statements executed per second
`mysql_commands_update`	Number of "UPDATE" statements executed per second
`mysql_commands_xa_commit`	Number of "XA COMMIT" statements executed per second
`mysql_commands_xa_end`	Number of "XA END" statements executed per second
`mysql_commands_xa_prepare`	Number of "XA PREPARE" statements executed per second
`mysql_commands_xa_recover`	Number of "XA RECOVER" statements executed per second
`mysql_commands_xa_rollback`	Number of "XA ROLLBACK" statements executed per second
`mysql_commands_xa_start`	Number of "XA START" statements executed per second
`mysql_commands_assign_to_keycache`	Number of assign-to-keycache commands per second
`mysql_handler_commit`	Number of internal commit requests per second
`mysql_handler_delete`	Number of rows deleted from tables per second
`mysql_handler_write`	Number of rows inserted per second
`mysql_handler_update`	Number of rows updated per second
`mysql_handler_rollback`	Number of transaction rollback requests given to a storage engine per second

Logs

Glouton collects MySQL and MariaDB logs for analysis in Bleemeo.

Monitoring Troubleshooting

See Troubleshoot a Service Check or Missing Metrics for what applies to every service: finding the address and port Glouton really uses, what each check message means, and how to read the collection error — which does not appear in the agent logs at the default level.

The Service Check is not OK

The check only opens the TCP port — it sends no query — so it fails for one of three reasons:

Status text	Cause	Fix
`TCP port 3306, Connection refused`	The server listens on another port, or not on TCP at all: `skip-networking`, or a `bind-address` that excludes the address Glouton uses	Set `address` and `port`, or allow TCP connections from the agent
`TCP port N, connection timed out after 10 seconds`	A firewall drops the packets	Open the port for the agent
`Invalid TCP address "..."`	A typo in the Glouton configuration	Fix the configuration

A MySQL reachable only through its UNIX socket cannot be checked: the check always uses TCP, and metrics_unix_socket covers the metrics only.

Metrics are Missing

A passing check says nothing about the metrics: they are collected separately.

Glouton needs a password to gather anything at all — without one it creates no MySQL collector, and only service_status is reported. The user defaults to root, and Glouton also picks up credentials from /etc/mysql/debian.cnf outside containers, or from MYSQL_ROOT_PASSWORD / MARIADB_ROOT_PASSWORD inside one.

With credentials in place, it runs SHOW GLOBAL STATUS, SHOW GLOBAL VARIABLES and reads information_schema.INNODB_METRICS.

Reproduce what Glouton does, from the machine where the agent runs:

mysql -h 127.0.0.1 -P 3306 -u glouton -p -e "SHOW GLOBAL STATUS LIKE 'Queries'; SELECT COUNT(*) FROM information_schema.INNODB_METRICS"

What you see	Cause	Fix
nothing — the collector is never created	No password configured	Set `password` in the Glouton configuration
`Access denied for user '...'@'...'`	Wrong credentials	Fix `username` and `password`
`Access denied for user 'root'@'127.0.0.1'` — connecting over TCP is not the same host as connecting over the socket	The user exists for `localhost` only	Grant the user for the address the agent uses, or point Glouton at the socket with `metrics_unix_socket`
`Access denied` on every password attempt	The user authenticates with `auth_socket` — the default for `root` on Debian and Ubuntu	Create a dedicated monitoring user with a password
an error on `information_schema.INNODB_METRICS`	Missing `PROCESS` privilege	Grant it: the `mysql_innodb_` metrics need it, the others do not — this is the usual cause of some* metrics missing
a connection error	The server requires TLS (`require_secure_transport`)	Allow non-TLS connections from the agent address

A minimal monitoring user:

CREATE USER 'glouton'@'127.0.0.1' IDENTIFIED BY 'PASSWORD';
GRANT PROCESS ON *.* TO 'glouton'@'127.0.0.1';