Resolving a 503 error

The 503 error appears when the server can't respond. The most common reason is that one or more server resources were exhausted. This includes CPU, RAM, processes, disk usage, and others.

503 errors caused by WP Rocket

When the 503 errors happen only while WP Rocket is active, it can be due to one of the following scenarios:

• CPU: One or more optimizations are hitting the CPU limit, or there is a misconfiguration in the way WP Rocket is working.
  
  Solution: To pinpoint and fix the problem, you should refer to the High CPU usage guide.


• PHP memory: The processing of the optimizations is exceeding the PHP memory limit.
  
  Solution: Increase the PHP memory as per this article.


• Disk space: The cache or optimizations are flooding the server disk.
  
  Solution: Identify the folder that's affected and adjust WP Rocket as shown in the Cache folder is getting too big tutorial.
  

Pre-existent 503 errors

When there are pre-existent 503 errors on your site, or these errors also happen when WP Rocket is not active, you should contact your hosting provider directly.