What does error code 504 mean?

When visiting a website which takes several minutes to load without having any output you might end up having an HTTP error 504 Gateway Timeout.

It’s very likely for PHP to still run on the background but since it is not giving any output the server or web browser finishes waiting when several minutes have passed.

HTTP error 504 can mean different things in different environments so this article is about what an error message means specifically in context of Seravo servers. Take notice that other online 504 error issues might not be related to Seravo environment at all. 

Error in PHP execution or planning

The main reason for an error could be in PHP execution or planning, in which PHP is trying to download excessive amount of content from a database or making an external API-request to another server which is not responding. This should be fixed so that the execution itself is made faster or in smaller partitions and that PHP echoes interim statements instead of not giving any output at all. Also the code itself might have a exception which aborts the execution without any error output.

Seravo offers several tools for developers to widely examine and analyze PHP logs as well as the speed and performance of PHP code.

More information can be found from the WordPress Developer Documents, for example:

• https://seravo.com/docs/development/xdebug/
• https://seravo.com/docs/development/tideways/
• https://seravo.com/docs/get-started/data-locations/#log-files

We can also assist the developer as an separately invoiced expert services to examine the PHP code in cases of this kind. 

Error on server

Error message can also turn up if there’s a server error which prevents the PHP code from running. In case of a shortcoming on behalf of Seravo systems, it will be informed in real time on Seravo status page.