Does MariaDB 5.5.56 have INFORMATION_SCHEMA.INNODB_METRICS?

Question

I'm trying to debug why I don't have INFORMATION_SCHEMA.INNODB_METRICS. I'm uncertain because I see it in the MySQL 5.5 reference glossary: https://dev.mysql.com/doc/search/?d=10&p=1&q=innodb_metrics.

mysql --version
mysql  Ver 15.1 Distrib 5.5.56-MariaDB, for Linux (x86_64) using readline 5.1

When I try to configure it through my.cnf I get:

mysqld: unknown variable "innodb_monitor_enable"

When I try to configure it through the MySQL CLI I get:

MariaDB [(none)]>  SET GLOBAL innodb_monitor_enable = trx_rw_commits;
ERROR 1193 (HY000): Unknown system variable 'innodb_monitor_enable'
MariaDB [(none)]>  SET GLOBAL innodb_monitor_enable = trx_nl_ro_commits;
ERROR 1193 (HY000): Unknown system variable 'innodb_monitor_enable'
MariaDB [(none)]>  SET GLOBAL innodb_monitor_enable = trx_ro_commits;
ERROR 1193 (HY000): Unknown system variable 'innodb_monitor_enable'
MariaDB [(none)]>  SET GLOBAL innodb_monitor_enable = trx_rollbacks;
ERROR 1193 (HY000): Unknown system variable 'innodb_monitor_enable'

My guess is that it was introduced in 5.6 because https://dev.mysql.com/doc/refman/5.5/en/innodb-information-schema-metrics-table.html redirects to 8.0 and 5.6 works.

Additional info

Turns out that, as shown below

SELECT VERSION()
    -> ;
+----------------+
| VERSION()      |
+----------------+
| 5.5.56-MariaDB |
+----------------+

...I was looking in the wrong place. I actually am using MariaDB as the database management system, and @danblack pointed out it was released in 10.

Answer 1

Your version string indicate your client version is MariaDB. Making the assumption that your server is too and looking at the MariaDB kb INFORMATION_SCHEMA.INNODB_METRICS was added in 10.0.

Answer 2

----- 2011-04-11 5.6.2 Developer Milestone -- INFORMATION_SCHEMA Table for InnoDB Metrics -- InnoDB -----

A new INFORMATION_SCHEMA table, INNODB_METRICS, lets you query low-level InnoDB performance information, getting cumulative counts, averages, and minimum/maximum values for internal aspects of the storage engine operation. You can start, stop, and reset the metrics counters using the innodb_monitor_enable, innodb_monitor_disable, innodb_monitor_reset, and innodb_monitor_reset_all system variables.

I can't say specifically when (or if) it was folded into MySQL other than to say that there is no hint of it being backported into MariaDB 5.5.

Answer 3

mysql --version only shows the version of the client, not the server. SELECT VERSION() is a good server indication.

Going by your assertion that you are really using MySQL and not MariaDB, I would concur with your guess that it was added in 5.6