TYPO3: OPcache activation causes server error in TYPO3 backend

Question

I have some trouble with TYPO3 and opcache activation and hope someone can help me :).

Environment details:

• PHP 7.1.10
• OPcache Version: 7.1.10
• TYPO3 7.6.23
• Alfahosting (Business XL (SSD))

Situation:

If I enable PHP7 without opcache option then everything is working fine, but if I enable PHP7 with opcache option then I got irregular 500 errors in the backend of TYPO3 and the site is down for a few seconds or minutes. After this few seconds I could reload the page and everything is working until the next server error appears. So it seems that a server process is restarting after this crash.

Actions like opening the extension configuration of the TYPO3 backend extension and press save will lead to the server error. The server logs and the error logs are empty and for this reason the Alfahosting support can't help me.

Furthermore I have mirrored the TYPO3 on two other webservers (not Alfahosting), also PHP7 and opcache option enabled and got no problems on this two webservers. After that I have installed a fresh TYPO3 7.6.23 on a Alfahosting webserver (see environment details above) and I got the annoying 500 server error again. So I think a specific Alfahosting server configuration leads to the 500 server errors if opcache is enabled, but I am not a server admin and I don't know how I could solve this problem without changing the hosting :(.

So I hope someone could help me? Maybe it's possible to track the error to find out where the problem is?

Answer 1

Just to clarify: You say, that the errors are not deterministic meaning, that you get errors on pages / urls which you can load without problems a few seconds / minutes later? Not good.

To tell the truth, I can't directly help you with this. Just give a few general hints.

What is your hosting package, do you install / configure operating system, php etc or the hoster? If it's the job of the hoster, they should help.

If the hoster can't help you with this, I would recommend switching the hoster and not waste more time on this. In any case they should configure the logging correctly. It's weird there is nothing in the error logs.

Try to activate (or get the hoster to activate) logging and check logfiles. But first check the TYPO3 system reports for any obvious errors:

• Run TYPO3 system report: "TYPO3 Backend" : "System" : "Reports" : "Status report"
• In the "TYPO3 Install Tool" check "System environment"

Now check the logs

• check the sys_log: "TYPO3 Backend" : "System" : "Log"
• check the Webserver / PHP logs
• check system logs (depends on operating system, eg journalctl )
• have a look at the output of phpinfo. It should include some OPcache statistics. Look at "wasted memory", "Free memory" and "OOM restart"

If you have root access to the system: Check opcache configuration, possibly adding more memory or post configuration here