Check mysql-aria

Overview

Checks metrics of the Aria storage engine in MariaDB, including the page cache size relative to total Aria index size and the page cache hit rate. Aria is the crash-safe, non-transactional storage engine used for internal temporary tables in MariaDB. It is not shipped with MySQL or Percona Server.

Important Notes:

• See additional notes for all mysql monitoring plugins

• User account requires access to INFORMATION_SCHEMA (user with no privileges is sufficient) and SELECT privileges on all schemas and tables to provide accurate results

• For most INFORMATION_SCHEMA tables, each MySQL user has the right to access them, but can see only the rows in the tables that correspond to objects for which the user has the proper access privileges. So you can’t grant permission to INFORMATION_SCHEMA directly, you have to grant SELECT permission to the tables on your own schemas, and as you do, those tables will start showing up in INFORMATION_SCHEMA queries.

• „total Aria indexes: 0.0B“ means that there are no Aria-based tables at all, or the user performing the check does not have SELECT privileges on them

Data Collection:

• Queries SHOW GLOBAL VARIABLES for aria_pagecache_buffer_size

• Queries SHOW GLOBAL STATUS for Aria_pagecache_reads and Aria_pagecache_read_requests

• Queries information_schema.tables to sum all Aria index sizes

• Logic is taken from MySQLTuner script:mariadb_aria()

Fact Sheet

Fact	Value
Check Plugin Download	https://github.com/Linuxfabrik/monitoring-plugins/tree/main/check-plugins/mysql-aria
Nagios/Icinga Check Name	check_mysql_aria
Check Interval Recommendation	Every hour
Can be called without parameters	No
Runs on	Cross-platform
Compiled for Windows	No
3rd Party Python modules	pymysql

Help

usage: mysql-aria [-h] [-V] [--always-ok] [--defaults-file DEFAULTS_FILE]
                  [--defaults-group DEFAULTS_GROUP] [--timeout TIMEOUT]

Checks metrics of the Aria storage engine in MySQL/MariaDB, including page
cache read and write hit rates. Alerts when cache efficiency drops below
optimal levels.

options:
  -h, --help            show this help message and exit
  -V, --version         show program's version number and exit
  --always-ok           Always returns OK.
  --defaults-file DEFAULTS_FILE
                        MySQL/MariaDB cnf file to read user, host and password
                        from (instead of specifying them on the command line).
                        Example: `/var/spool/icinga2/.my.cnf`. Default:
                        /var/spool/icinga2/.my.cnf
  --defaults-group DEFAULTS_GROUP
                        Group/section to read from in the cnf file. Default:
                        client
  --timeout TIMEOUT     Network timeout in seconds. Default: 3 (seconds)

Usage Examples

./mysql-aria --defaults-file=/var/spool/icinga2/.my.cnf

Output:

Aria pagecache size / total Aria indexes: 128.0MiB/328.0KiB, 97.2% Aria pagecache hit rate (1.1K cached / 30.0 reads)

States

• WARN if aria_pagecache_buffer_size < total Aria indexes and the page cache hit rate is below 95%.

• --always-ok suppresses all alerts and always returns OK.

Perfdata / Metrics

Name	Type	Description
mysql_aria_pagecache_buffer_size	Bytes	The size of the buffer used for index and data blocks for Aria tables.
mysql_aria_pagecache_read_requests	Continuous Counter	The number of requests to read something from the Aria page cache.
mysql_aria_pagecache_reads	Continuous Counter	The number of Aria page cache read requests that caused a block to be read from the disk.
mysql_pct_aria_keys_from_mem	Percentage	aria_pagecache_reads / aria_pagecache_read_requests * 100
mysql_total_aria_indexes	Bytes	Sum of all Aria index sizes.

Credits, License

• Authors: Linuxfabrik GmbH, Zurich

• License: The Unlicense, see LICENSE file.

• Credits:

  • heavily inspired by MySQLTuner (https://github.com/major/MySQLTuner-perl)