Azure Database for MySQL flexible server - CPU stuck at 100% and all connection fails

Question

Hello,

1 hour ago my website was offline: I checked the database and I found that the Azure Database for MySQL flexible server has the CPU stuck at 100% from 6 hours and all connection fails.

I restart the server and currently is in restarting state for an hour.

The Activity Log of the last 24 hours reports:

List changes of a single resource
Succeeded
36 minutes ago
Thu Feb 20 2025 13:12:41 GMT+0100 (Ora standard dell’Europa centrale)

List changes of a single resource
Succeeded
36 minutes ago
Thu Feb 20 2025 13:12:18 GMT+0100 (Ora standard dell’Europa centrale)

Batch Update Server Configurations
Accepted
45 minutes ago
Thu Feb 20 2025 13:03:21 GMT+0100 (Ora standard dell’Europa centrale)

List changes of a single resource
Succeeded
49 minutes ago
Thu Feb 20 2025 12:59:19 GMT+0100 (Ora standard dell’Europa centrale)

Restart MySQL Server
Accepted
53 minutes ago
Thu Feb 20 2025 12:55:24 GMT+0100 (Ora standard dell’Europa centrale)

Can you please help me?

Thanks,

Nicola

Answer 1

Hi Nicola,

seems like your MySQL server decided to throw a proper tantrum! CPU at 100% for 6 hours? That’s like trying to run a marathon while carrying a fridge just a joke u know :))))

First off, the restart taking forever is a classic Azure (hang in there, buddy:) moment. While you wait, check if there’s any rogue query hogging all the resources sometimes it’s just one sneaky

SELECT * FROM chaos;

(I add code lol) causing all the trouble. If the server comes back online, maybe scale up the instance temporarily to buy yourself some breathing room. And if it happens again, Azure Support might need to step in before your server starts writing its own error logs for fun.

warm rgds,

alex