Error 503 Backend fetch failed

Ksasa · October 28, 2022, 8:43am

I can’t access to my matomo server installation anymore.
I get this error:

Backend fetch failed
Guru Meditation:

XID: 54112105

Varnish cache server

What should I do now?

heurteph-ei · October 28, 2022, 9:12am

Hi @Ksasa
Check the error log file

Ksasa · October 28, 2022, 9:20am

Hi Philippe, do you mean matomo.log? I don’t have this file in /tmp/logs/
Or I have to check in some other locations?

heurteph-ei · October 28, 2022, 9:34am

Have a look at:

Ksasa · October 28, 2022, 9:43am

Ok thanks, it started loggin in there:

ERROR Piwik\ExceptionHandler[2022-10-28 09:37:42 UTC] [1a26a] Uncaught exception: /my_matomo_path/matomo/core/Nonce.php(236): Non è possibile verificare il token di sicurezza di questo form. [Query: ?module=CoreUpdater&action=oneClickUpdate&nonce=ecd4ac49923d91c7b061eb4699777884, CLI mode: 0]

the error is written in Italian, the english translation is:
It is not possible to verify the security token of this form

The system writes 3 lines of this error at every access attempt.
it’s the only kind of error shown in the log.

heurteph-ei · October 28, 2022, 12:03pm

Hi,

Try to remove any stored data in your browser or navigate in Private mode. Probably some cookie has not been deleted…

Ksasa · October 28, 2022, 2:46pm

so… it turns out that this only happens trying to access at index.php?module=CoreUpdater&action=newVersionAvailable
when there is not a new available version. When entering from index.php all works fine.
Still seems strange to me that entering in the CoreUpdater returns that 503 error. I have also tried entering from another browser, never used before for that matomo installation and there’s the same problem.