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Check mysql-innodb-log-waits

Overview

Checks the number of times InnoDB was forced to wait for log writes to be flushed due to the log buffer being too small in MySQL/MariaDB. Logic is taken from MySQLTuner script:mysql_innodb(), v1.8.3.

Hints:

Fact Sheet

Fact Value
Check Plugin Download https://github.com/Linuxfabrik/monitoring-plugins/tree/main/check-plugins/mysql-innodb-log-waits
Check Interval Recommendation Once an hour
Can be called without parameters Yes
Compiled for Windows No
Requirements User with no privileges, locked down to 127.0.0.1 - for example monitoring\@127.0.0.1. Usernames in MySQL/MariaDB are limited to 16 chars in specific versions.
3rd Party Python modules pymysql

Help

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

Checks the number of times InnoDB was forced to wait for log writes to be
flushed due to the log buffer being too small in MySQL/MariaDB.

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
                        Specifies a cnf file to read parameters like user,
                        host and password from (instead of specifying them on
                        the command line), for 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-innodb-log-waits --defaults-file=/var/spool/icinga2/.my.cnf

Output:

0.0 InnoDB log buffer waits / 867.6K writes.

States

  • WARN if the number of times InnoDB was forced to wait for log writes to be flushed is > 0.

Perfdata / Metrics

Name Type Description
mysql_innodb_log_buffer_size Bytes Size in bytes of the buffer for writing InnoDB redo log files to disk. Increasing this means larger transactions can run without needing to perform disk I/O before committing.
mysql_innodb_log_waits Continous Counter Number of times InnoDB was forced to wait for log writes to be flushed due to the log buffer being too small.
mysql_innodb_log_writes Continous Counter Number of writes to the InnoDB redo log.

Credits, License