MySQL & MariaDB Performance Tuning using Mysqltuner

MySQL and MariaDB are among the most widely used open-source relational database management systems. They power a significant portion of the web’s most visited services and applications. As usage increases, performance tuning becomes paramount to optimize MySQL and prevent issues like slow queries. This article focuses on MySQL & MariaDB Performance Tuning using Mysqltuner.

Mysqltuner is an open-source Perl script designed to analyze and tune MySQL performance. It offers configuration and performance recommendations to optimize MySQL. This comprehensive guide will cover the ins and outs of using Mysqltuner for MySQL & MariaDB Performance Tuning using Mysqltuner.

Overview of mysqltuner

Mysqltuner is a Perl script created and maintained by Major Hayden. It connects to a MySQL server, performs diagnostics, and provides configuration and tuning advice aimed at improving overall performance. It’s a crucial tool for MySQL & MariaDB Performance Tuning using Mysqltuner.

Key features of mysqltuner include:

Comprehensive analysis of MySQL server configuration and performance metrics.
Clear and actionable recommendations for improving performance.
Identification of potential bottlenecks and areas for optimization.
Support for various MySQL versions and configurations.
Ease of use and installation.

Mysqltuner is user-friendly and provides clear, actionable recommendations. It serves as a valuable tool for MySQL performance monitoring and tuning.

Installing mysqltuner

Mysqltuner is a standalone Perl script. To install it:

Install Perl (if not already installed):

$ sudo apt install perl

Download the mysqltuner script:

$ wget https://raw.githubusercontent.com/major/MySQLTuner-perl/master/mysqltuner.pl

Make the script executable:

$ chmod +x mysqltuner.pl

Move the script to a directory in your PATH (e.g., /usr/local/bin):

$ sudo mv mysqltuner.pl /usr/local/bin/mysqltuner

Now mysqltuner is installed and ready to use!

Using mysqltuner is simple. Just run the script with your MySQL credentials:

$ mysqltuner --host localhost --user root --pass password

This will connect to the MySQL server on localhost as the root user, run diagnostics, and print a report.

To save the report to a file:

$ mysqltuner --host localhost --user root --pass password > mysqlreport.txt

Key options include:

--host: The hostname or IP address of the MySQL server.
--user: The MySQL username.
--pass: The MySQL password.
--socket: The path to the MySQL socket file.
--mysqladmin: The path to the mysqladmin command-line tool (if not in your PATH).

Review the report for performance advice and apply the recommendations. Rerun mysqltuner periodically to monitor changes over time.

Interpreting mysqltuner Recommendations

The mysqltuner report contains many metrics and suggestions. Here are some key areas to focus on:

Performance Metrics

Uptime: How long the MySQL server has been running. Longer uptimes provide more data for analysis.
Threads Connected: The number of active client connections. High numbers may indicate connection bottlenecks.
Query Cache Hit Rate: The percentage of queries served from the query cache. A low hit rate suggests the query cache is not effective.
Key Efficiency: The efficiency of the key buffer (for MyISAM tables). A low efficiency indicates the key buffer is too small.
Table Cache Hit Rate: The percentage of table opens served from the table cache. A low hit rate suggests the table cache is too small.
Temporary Tables: The number of temporary tables created on disk. High numbers may indicate insufficient memory or inefficient queries.

Configuration Suggestions

Increasing buffer sizes: Increase key_buffer_size, innodb_buffer_pool_size, table_open_cache, query_cache_size, and other relevant buffer sizes to improve caching.
Adjusting connection limits: Increase max_connections to accommodate more client connections.
Optimizing logging: Adjust logging settings to reduce overhead and improve performance.
Tuning the query cache: Adjust query_cache_type and query_cache_size to optimize query caching.
InnoDB specific tuning: Adjust settings like innodb_log_file_size and innodb_flush_log_at_trx_commit.

Hardware Suggestions

Memory: Ensure sufficient RAM to accommodate buffer pools and other memory allocations.
CPU: Monitor CPU utilization to identify potential CPU bottlenecks.
Disk I/O: Monitor disk I/O to identify potential disk bottlenecks. Consider using SSDs for improved performance.

Query Performance

Slow Queries: Identify and optimize slow queries. Use slow_query_log and long_query_time to log and analyze slow queries.
Missing Indexes: Identify tables with missing indexes. Add indexes to improve query performance.
Full Table Scans: Identify queries performing full table scans. Optimize queries or add indexes to avoid full table scans.

Implementing mysqltuner Recommendations

Here are some steps to act on mysqltuner recommendations and tune MySQL performance:

Review the mysqltuner report carefully. Understand the recommendations and their potential impact.
Prioritize recommendations based on their potential impact and ease of implementation. Start with the simplest and most impactful changes.
Make incremental changes to the MySQL configuration file (my.cnf or my.ini). Avoid making too many changes at once.
Restart the MySQL server after making changes.
Monitor performance after each change. Use mysqltuner and other monitoring tools to assess the impact of the changes.
Adjust settings as needed based on performance monitoring.
Repeat steps 3-6 until the desired performance is achieved.

With diligent tuning guided by mysqltuner, you can optimize MySQL to handle heavy workloads and deliver maximum performance. The key is regularly reviewing metrics and incrementally applying recommendations over time.

MySQLTuner Script Explained

The mysqltuner.pl script is well structured and extensively commented. Let’s walk through the main sections to understand what it does under the hood:

Initial Connection

Parses command line arguments for MySQL credentials (host, user, password, socket).
Connects to the MySQL server using the provided credentials.
Checks MySQL version and validates that the script supports it.

Data Collection

Collects a wide range of MySQL server configuration variables using SHOW VARIABLES.
Collects performance metrics using SHOW GLOBAL STATUS.
Queries the INFORMATION_SCHEMA database to gather information about tables, indexes, and queries.

Analysis and Reporting

Analyzes the collected data to identify potential performance bottlenecks.
Calculates key performance ratios and metrics (e.g., query cache hit rate, key efficiency).
Generates a report with recommendations for improving performance, including specific configuration changes and hardware upgrades.

Connection Cleanup

Closes the connection to the MySQL server.

This shows the basic flow – connect, gather data, analyze, print report, disconnect. The heavy lifting is done by the data collection and analysis sections. MySQLTuner relies on SHOW commands and INFORMATION_SCHEMA queries to get configuration values and performance metrics.

Ways to Use MySQLTuner

In addition to ad-hoc tuning, here are other good ways to leverage mysqltuner:

Application Testing – Run mysqltuner on development, staging, and production to compare configurations. Fine tune each environment.
New Database Server – Create a baseline report after provisioning a new database server. Use for initial sizing and tuning.
Performance Trends – Execute mysqltuner over time and save reports. Check for trends as database grows.
After Upgrade – How is performance after a MySQL or OS upgrade? Run mysqltuner to verify.
Cloud Migration – Migrating from bare metal to cloud? A mysqltuner report helps rightsize the instance.
Capacity Planning – Planning a storage, memory, or compute expansion? Mysqltuner indicates where resources are needed.
Diagnostics – If MySQL is slow, run mysqltuner to help uncover the bottlenecks.

These examples demonstrate the wide applicability of mysqltuner for various performance monitoring and tuning scenarios.

While mysqltuner is easy to use and full featured, there are other MySQL tuning tools to consider:

Percona Toolkit: A suite of advanced command-line tools for MySQL server management, including pt-query-digest for analyzing slow query logs.
phpMyAdmin: A web-based MySQL administration tool that provides a graphical interface for monitoring and tuning MySQL.
MySQL Enterprise Monitor: A commercial monitoring tool from Oracle that provides real-time performance monitoring and analysis.

Mysqltuner makes an excellent starting point due to its ease of use and clear results. Complement it with other tools that provide drilling down capabilities for advanced tuning.

Alternative Solutions for MySQL & MariaDB Performance Tuning

While Mysqltuner is a valuable tool, other approaches can be used for MySQL performance tuning. Here are two alternative solutions:

1. Using Performance Schema for Real-time Monitoring and Tuning:

The Performance Schema, enabled by default in MySQL 5.6.3 and later, provides a low-level mechanism for monitoring MySQL server execution. Unlike traditional methods that rely on snapshots or logs, the Performance Schema offers near real-time insights into server behavior.

Explanation: The Performance Schema collects data about various aspects of MySQL server operation, such as statement execution, wait events, and memory allocation. This data can be queried using SQL, allowing you to identify bottlenecks and areas for optimization. For instance, you can track the execution time of individual queries, identify the most frequent wait events, and monitor memory usage by different components.
Code Example:

First, enable the necessary instruments and consumers. This example enables statement instrumentation:

UPDATE performance_schema.setup_instruments SET enabled = 'YES' WHERE name LIKE 'statement/%';
UPDATE performance_schema.setup_consumers SET enabled = 'YES' WHERE name LIKE 'global_summary%';

Then, you can query the events_statements_summary_global_by_event_name table to find the events that are taking the most time:

SELECT EVENT_NAME, COUNT_STAR, SUM_TIMER_WAIT FROM performance_schema.events_statements_summary_global_by_event_name ORDER BY SUM_TIMER_WAIT DESC LIMIT 10;

This will show the top 10 events that are taking the most time. From there, you can investigate the specific statements that are causing those events.

Using events_statements_history_long, you can get more detailed info about specific long-running queries:

SELECT SQL_TEXT FROM performance_schema.events_statements_history_long WHERE TIMER_WAIT > 10000000000 ORDER BY TIMER_WAIT DESC LIMIT 1;

This retrieves the SQL text of the longest running query (queries running for more than 10 seconds).

By analyzing this data, you can identify slow queries, inefficient indexes, and other performance bottlenecks, allowing you to make targeted optimizations.

2. Using ProxySQL for Query Routing and Caching:

ProxySQL is a high-performance, high-availability proxy server for MySQL. It sits between your application and your MySQL servers, intercepting and routing traffic based on predefined rules.

Explanation: ProxySQL can be used to improve performance in several ways. It can cache frequently executed queries, reducing the load on the MySQL servers. It can also route queries to different servers based on factors such as query type, user, or time of day. This allows you to distribute the load across multiple servers and optimize performance for specific workloads. Furthermore, ProxySQL can provide connection pooling, reducing the overhead of establishing new connections to the database.
Code Example (ProxySQL configuration):

First, configure the MySQL hostgroups and servers. Assuming you have two MySQL servers (192.168.1.10 and 192.168.1.11), you’d add them to ProxySQL like this (using the ProxySQL admin interface or CLI):

INSERT INTO mysql_servers (hostgroup_id, hostname, port) VALUES (1, '192.168.1.10', 3306);
INSERT INTO mysql_servers (hostgroup_id, hostname, port) VALUES (2, '192.168.1.11', 3306);

Then, add rules to route traffic to the appropriate hostgroups:

INSERT INTO mysql_query_rules (rule_id, match_pattern, destination_hostgroup, apply) VALUES (1, '^SELECT .*', 1, 1);
INSERT INTO mysql_query_rules (rule_id, match_pattern, destination_hostgroup, apply) VALUES (2, '^INSERT .*', 2, 1);

This example routes all SELECT queries to hostgroup 1 (server 192.168.1.10) and all INSERT queries to hostgroup 2 (server 192.168.1.11).

To enable caching, you could set the cache TTL in the query rules:

UPDATE mysql_query_rules SET cache_ttl_ms=60000 WHERE rule_id=1;

This will cache SELECT queries for 60 seconds (60000 milliseconds).

ProxySQL allows for very granular control over query routing and caching, enabling you to optimize performance based on the specific needs of your application.

Conclusion

mysqltuner is an invaluable tool for monitoring and tuning MySQL & MariaDB performance. It quickly diagnoses problems and offers clear, actionable suggestions for improvement.

Following mysqltuner’s advice can help resolve or avoid many common MySQL performance pitfalls. It’s an essential tool for any database administrator or application developer using MySQL in production.

Consistent use of mysqltuner and other complementary tools, as well as alternative solutions like Performance Schema and ProxySQL, will maximize database efficiency, reduce infrastructure costs, and provide the best experience for applications and their users. Properly using MySQL & MariaDB Performance Tuning using Mysqltuner can be a game changer.