We are managing an Azure Database for MySQL and we received an alert that CPU usage has spiked to 90% and stayed high for the last 30 minutes. The application team says the database performance has become very slow. How would we go about identifying the r

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We are managing an Azure Database for MySQL and we received an alert that CPU usage has spiked to 90% and stayed high for the last 30 minutes. The application team says the database performance has become very slow. How would we go about identifying the r

Saisantosh Sadnnah 20

We are managing an Azure Database for MySQL and we received an alert that CPU usage has spiked to 90% and stayed high for the last 30 minutes. The application team says the database performance has become very slow. How would we go about identifying the root cause and resolving this issue? Please walk me through your approach?

Sai Raghunadh M 4,640 Reputation points Microsoft External Staff Moderator

2025-05-08T12:34:32.1233333+00:00

Hi @ Saisantosh Sadnnah

If your Azure Database for MySQL is experiencing sustained high CPU usage, Try the below steps to speed up the performance of your database.

Identify High-CPU Queries

Use Azure Monitor Metrics to check CPU trends.

Run SHOW PROCESSLIST; in MySQL to identify long-running queries.

Check the slow query log (SET GLOBAL slow_query_log = 1;) to find expensive queries.

Analyze Query Performance

Use EXPLAIN or EXPLAIN ANALYZE to inspect execution plans.

Ensure indexes are used efficiently (SHOW INDEX FROM table_name;).

Optimize queries by reducing unnecessary joins and subqueries.

Scale or Adjust Resources

If workload has increased, consider vertical scaling (upgrading your instance size).

Use read replicas to distribute the load efficiently.

Use connection pooling to avoid overloading the database.

Enable read replicas for scalability.

Implement caching (e.g., Redis) to reduce database load.

Hope this helps. Do let us know if you have any further queries. so that we will assist you better.
Saisantosh Sadnnah 20 Reputation points

2025-05-08T20:09:57.0333333+00:00

How to check MySQL process list to see which queries are running for too long?
Saisantosh Sadnnah 20 Reputation points

2025-05-09T19:05:30.0066667+00:00

Thankyou so much. Optimizing long running queries solved my issue

Accepted answer

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Your answer

Sai Raghunadh M 4,640 Reputation points Microsoft External Staff Moderator

2025-05-08T12:34:32.1233333+00:00

Hi @ Saisantosh Sadnnah

If your Azure Database for MySQL is experiencing sustained high CPU usage, Try the below steps to speed up the performance of your database.

Identify High-CPU Queries

Use Azure Monitor Metrics to check CPU trends.

Run SHOW PROCESSLIST; in MySQL to identify long-running queries.

Check the slow query log (SET GLOBAL slow_query_log = 1;) to find expensive queries.

Analyze Query Performance

Use EXPLAIN or EXPLAIN ANALYZE to inspect execution plans.

Ensure indexes are used efficiently (SHOW INDEX FROM table_name;).

Optimize queries by reducing unnecessary joins and subqueries.

Scale or Adjust Resources

If workload has increased, consider vertical scaling (upgrading your instance size).

Use read replicas to distribute the load efficiently.

Use connection pooling to avoid overloading the database.

Enable read replicas for scalability.

Implement caching (e.g., Redis) to reduce database load.

Hope this helps. Do let us know if you have any further queries. so that we will assist you better.
Saisantosh Sadnnah 20 Reputation points

2025-05-08T20:09:57.0333333+00:00

How to check MySQL process list to see which queries are running for too long?
Saisantosh Sadnnah 20 Reputation points

2025-05-09T19:05:30.0066667+00:00

Thankyou so much. Optimizing long running queries solved my issue

Answer 1

Hi @ Saisantosh Sadnnah

To check which queries are running for too long in MySQL, you can use the SHOW PROCESSLIST; command. This command displays a list of currently running threads, including their execution time, state, and query details. If you want to see the full query text, use SHOW FULL PROCESSLIST; instead.

Additionally, you can query the INFORMATION_SCHEMA.PROCESSLIST table to get more detailed insights into running queries:

SELECT * FROM INFORMATION_SCHEMA.PROCESSLIST WHERE TIME > 30;

This will show queries that have been running for more than 30 seconds, helping you identify potential bottlenecks.

Please go through these similar threads that might help you:

https://stackoverflow.com/questions/16571416/how-can-i-get-a-full-list-of-all-queries-currently-running-on-my-mysql-server?__cf_chl_tk=CTgxgvNg.716trB2a7GHtVwWaYdmGN4mnZTA4pbPr7o-1746790617-1.0.1.1-CnzuMDJYFzTAhHQYTrhkNh.WofVk4WYj1NBQW16T1vk

https://stackoverflow.com/questions/3638689/how-to-see-full-query-from-show-processlist

Hope this helps. Do let us know if you any further queries.

If this answers your query, do click Accept Answer and Yes for was this answer helpful. And, if you have any further query do let us know.

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We are managing an Azure Database for MySQL and we received an alert that CPU usage has spiked to 90% and stayed high for the last 30 minutes. The application team says the database performance has become very slow. How would we go about identifying the r

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