I have to reopen this again:
Now the same issue again: When I want to adopt the newly modifications, I run into the same time out.
Clearing the caches as suggested above does not work. I have to reboot the complete server.
When I click on "Adopt changes" (? - german: "Änderungen übernehmen"), Plesk is busy for 4,5min to process the request, activation takes another 2 minutes.
So Plesk needs 6,5min to rewrite the firewall rules. Server is a dual quadcore system with 8x3,54GHz (Intel(R) Xeon(R) CPU E3-1270 v3 @ 3.50GHz).
WTF??? What is Plesk doing here? Recompiling the kernel? Mining some bitcoins? Or is it just an inefficient slow and time wasting piece of software?
Back to the initial issue:
Does this mean that I have now to reboot the server every time when I have to modify a firewall rule? Not because of the ruleset itself but plesk as the failing management platform? O ****...