[Krydos] 50x errors

[tdm]

Hi !

I noticed numerous 502 - 503 - 504 errors on Tommy since several days.

Any idea ?

 

 

 

[wolstech]

502 is related to Apache restarting and is normal. Should occur approximately every 2 hours and usually lasts 5-10 minutes. If you're unable to tolerate this, you would need to move to Morty, where the Apache restarts currently take under a minute. Note that on Morty, you'll get a 504 instead of a 502 during an Apache restart.

504 on Tommy can happen if your script takes too long. It basically means nginx timed out waiting for Apache to return content, which is usually caused by your website's code taking too long and not finishing. This can be caused by many things, including high server load or badly written code. 

503 Service Unavailable is an unusual error to get on Tommy though, and I do see a few instances of that in your logs. I'm not sure what would cause this error specifically. Perhaps Krydos would know?

 

 

[Krydos]

2 hours ago, wolstech said:

Note that on Morty, you'll get a 504 instead of a 502 during an Apache restart.

Morty Apache restarts take between 4 to 9 seconds over the last month, so it would be impossible to see a 504 error because the restart needs to take more than 30 to 60 seconds seconds for it to actually timeout. During a 9 second Apache restart the page would just spin for an extra couple seconds during loading, and then display the website without any error. Nobody is ever even going to notice that, and it would be indistinguishable from your internet lagging slightly. Right now Morty has 608 virtualhosts so we would likely need to triple or quadruple that number in order for a 504 error to be possible.

2 hours ago, wolstech said:

503 Service Unavailable is an unusual error to get on Tommy though

503 error on a PHP script is likely the PHP script running for too long and getting killed. Perhaps try benchmarking your PHP scripts and see how long they are running for. Your load looks fine so we could increase your PHP timeout if you need, but it might not be necessary if you can optimize your code to not have to run for so long.