The document provides an overview of MySQL Performance Schema. It discusses what Performance Schema is, how it works, key terminology like instruments and consumers, and how instruments collect data. It also covers the different types of tables in Performance Schema, how instruments and available metrics have evolved in different MySQL versions, and how the sys schema presents Performance Schema data to users.

1. Mysql Performance Schema in Action
Presenter by
S Kannan
Database Engineer
Mydbops 12th Webinar
www.mydbops.com info@mydbops.com

2. ❏ Database Engineer
❏ Interest on Mysql and its related tech
❏ Active Learner
About Me

3. Mydbops at a Glance
● Founded in 2015, HQ in Bangalore India, 70+ Employees.
● Mydbops is on Database Consulting with core specialization on MySQL, MongoDB and PostgreSQL
Administration and Support.
● Mydbops was created with a motto of developing a DevOPS model for Database Administration.
● We help organisations to scale in MySQL/Mongodb/postgresql and implement the advanced technologies in
MySQL/Mongodb/PostgreSQL.

4. Mydbops at a Glance
Happy Customers
4

5. Agenda
● Introduction
● Performance Schema
● How performance schema Works ?
● Performance schema Terminology
● What is Instruments and how instruments get Data
● Instruments on various Mysql version
● Sys schema
● Demo

6. Introduction

7. What is Performance schema ?
❏Performance Schema is a feature for monitoring MySQL Server execution at a low level .
❏It was introduced in MySQL 5.5 .
❏It provides a way to inspect internal execution of the server at runtime .
❏Performance Schema events are specific to a given instance of the MySQL Server
❏It gives an insight what is happening behind the screen .
❏It was implemented as a Storage engine.

8. Performance Schema terminology
❖Actor
❖Consumer
❖Digest
❖Dynamic Configuration
❖Event
❖Instrument
❖Object
❖Setup Table
❖Summary table
❖Threads

9. How Performance Schema Works ?

10. Instruments:
❖Instruments are the code points where the measurements are done.
❖There are two types of instruments:
1) Timed instruments (Events)
2) Untimed instruments (count errors and memory usage)
❖Name of the monitored activity
❖Stored in performance_schema.setup_instruments table
❖More than 1200 instruments are in mysql 8

11. Config Server:
● Config servers store metadata and configuration settings for the cluster. As of MongoDB 3.4, config servers must
be deployed as a replica set (CSRS).
● If your cluster has a single config server, then the config server is a single point of failure.
● If the config server is inaccessible, the cluster is not accessible.
● If you cannot recover the data on a config server, the cluster will be inoperable.
● Always use three config servers for production deployments
How Instruments get data ?

12. S Consumers:
❖ It Process the data collected by the instruments and make it available on performance schema
❖ The consumers are defined in the setup_consumers table
❖ consumer name has a column to specify whether the consumer is enabled

13. S Events:
❖ An event is the result of a consumer recording the data collected by an instrument.
❖ It is used to observe the flow in mysql.
❖ Events are linked such that in general an event both has a parent and one or more child event.

14. S Event Types:
❖ Transactions
❖ Statements
❖ Stages
❖ Waits

15. S Threads:
❏ A thread is a fundamental concept in the Performance Schema.
❏ It handles a connections or Performing background operations.
❏ Mysql have several threads in parallel .
❏ Each thread has an Id (thread id).
❏ Stored in performance_schema.threads table

16. Performance Schema Table Types:
❖ Setup
❖ Event
❖ Instance
❖ Summary
❖ Histogram
❖ Connections and Threads
❖ Replication
❖ Lock
❖ Variable
❖ Clone
❖ Miscellaneous

17. S Statistics tables in performance schema
❖ Setup tables
❖ Events tables
❖ Summary tables
❖ Instance tables
❖ Lock tables
❖ Replication Summary

18. Instruments on various mysql version:

19. nstruments on various mysql version:
Mysql 5.6 Mysql 8
52 Tables 102 Ta
561 Instruments 10202 Instrume
589 ( percona server) 1229 (percona ser
31 Variables 44 variab
Mysql
87 Ta
1029 Instrume
1067 ( percona ser
42 Variables

20. High level Instruments on mysql 8
❏Memory
❏Idle
❏Stage
❏Transaction
❏Wait
❏Statement
❏error

21. S Sys schema:
❖ Sys schema reads and present the data.
❖ This is "user friendly" Performance Schema .
❖ The sys schema includes tables and triggers, views, and stored procedures and functions .
❖ The sys schema contains many views that summarize Performance Schema tables in various ways.
❖ Sys schema objects can be used for typical tuning and diagnosis use cases .

22. Unclosed Connections not closed properly :

23. Unused Index:

24. User created temporary tables on disk: