Archiving process is taking more than one day and option doesn't work

Hello,
We are running an instance of Matomo that is monitoring more than a 1000 websites so far.
Since a few months the archiving process start to cause us some issues. It can run sometimes for more than a day (without any error).
We have tried to increase the number of concurrent archivers ( --concurrent-archivers ) but it seems not to work. I don’t see a different number in the logs like mention in the documentation here: https://fr.matomo.org/faq/on-premise/how-to-set-up-auto-archiving-of-your-reports/
We are running in 3.14.1 still

Don’t hesitate to ask for more information I’ll be appy to share !

Hi @canda_j
As version 3.14 is quite old now, and version 4.x got several performance improvements, is it possible for you first to upgrade to version 4.x? 4.14.1 seems stable… (I would suggest do the migration in 2 times: 3.14.1 → 4.0.5 → 4.14.1)