Excessive database latency can make your application feel slow, no matter how fast the rest of your system may be.
Because SQL queries are at the heart of most applications, measuring the performance of your database server is critical for understanding where to focus efforts when trying to improve overall application speed.
There are several reasons why a database might not be performing well: an inefficient query, excessive load, contention among queries, or a lack of available memory.
Measuring database performance is one way to ensure a database is functioning as efficiently as possible. You can measure database performance in the following ways:
Using Database Performance Metrics
Database performance metrics are generated by database management systems (DBMS) to help you monitor the overall health of your database. The three most significant include:
These metrics measure how well the DBMS is functioning, including aspects such as availability, reliability, and durability. Standard operational metrics include uptime, downtime, number of required restarts, and number of registered databases.
Database Resource Consumption Metrics
These metrics measure the resources the database is using, including memory, disk space, and CPU utilization. Database resource consumption metrics can help you determine if you need to scale up (add more resources) or scale-out (multiple instances).
These metrics measure the resources consumed by specific SQL queries, including the number of reads and writes, disk space usage, and execution time. Using these metrics allows you to determine which queries are causing performance problems so you can optimize them.
Measuring Database Performance with MySQL
MySQL includes several built-in tools that allow you to monitor the performance of your database. These include:
MySQL Enterprise Monitor
Using a MySQL monitor is one the easiest ways to monitor MySQL performance, and it’s included free with MySQL Enterprise Edition.
You can use this tool to view historical trends in resource usage and create complex alerts when certain conditions occur, such as high-latency queries or backups that fail for a specific database.
This graphical tool includes several performance monitoring capabilities, including the ability to view current query execution time and load, top sessions by queries or connections, and SQL explain plan for slow or resource-intensive queries.
There are many third-party tools available that can provide customizable views of MySQL metrics. Some are free, while others charge a fee for their features. You can also use open-source tools, such as MySQL Query Browser, which provides graphical views of query performance.
Average Query Execution
Time (ms) is another standard metric used to measure database performance. This metric tells you how long each query takes to execute. While the lower the number, the better, this isn’t always an accurate way of measuring performance.
Queries executed less frequently will appear to consume more resources than they do because their average time is higher than the average time of more regularly executed queries.
The best way to monitor your database’s average query execution time is by using MySQL Enterprise Monitor, which captures real-time information about your database and its performance. Alternatively, you can use MySQL Query Browser or an open-source tool such as MySQLTuner.
Database performance is a critical component of application and system performance. Even the most powerful server will fail to meet the performance demands of its users if it isn’t correctly configured or has a poorly performing database.
To ensure your databases are performing as expected, you should monitor them regularly.
There are many open-source tools available that allow you to monitor the most critical metrics to your application. If you don’t have the resources for an open-source or commercial tool, you can use existing MySQL tools to monitor your databases directly.
By monitoring these metrics regularly, you’ll have all of the information you need to optimize your databases and ensure they are performing as expected.