Performance schema support

[ldangeard-orange]

This PR optionally enables operators to enable performance_schema feature in MariaDB. This requires setting the cf_mysql.mysql.performance_schema_enabled property to true in mysql instance group (default is false)

The performance_schema instrument flags (e.g. performance_schema_max_file_handles) are given sensible defaults based on Orange production usage (which sometimes slightly differ from mariadb defaults). Documentation mentions possible memory impact of turning on the feature and ways to measure it.

Background

The Performance Schema is a feature for monitoring server performance, see related mariadb documentation.

Performance_schema database, consists of a number of tables that can be queried with regular SQL statements, returning specific performance information.

Numerous community monitoring tools leverage the Performance Schema feature, such as :

• Collector Flags of prometheus mysql exporter
• Graphana dashboard (e.g. Percona plugin)

[cfdreddbot]

Hey ldangeard-orange!

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[cf-gitbot]

We have created an issue in Pivotal Tracker to manage this:

https://www.pivotaltracker.com/story/show/152429628

The labels on this github issue will be updated when the story is started.

[ldangeard-orange]

I make an error. I close this PR and create a new one.

[menicosia]

@ldangeard-orange, okay, we'll look forward to that.

We went through this one, and had decided to ask you for more information; specifically, as a PM, I wasn't sure what this was contributing since cf-mysql-release enables Performance Schema by default?

Nota Bene: with the upgrade to MariaDB 10.1.26, we are now offering the same performance schema as in MySQL 5.6.37.

No need to reply on this PR if you plan to open a new one; just definitely try to help us understand how the value changes as we try to understand your contribution. I think most of what you are offering is a tuning of performance schema so that more information is properly instrumented?

Thank you!

-- Marco Nicosia Product Manager Pivotal Software, Inc.

[ldangeard-orange]

We create a new PR #190 on correct develop branch. In MariaDB distribution , by default performance_schema is OFF since 10.0.12. https://mariadb.com/kb/en/library/performance-schema-system-variables/#performance_schema