I'm curious as to how many DirectAdmin server administrators are using the Isolated PHP-FPM setup that became available in DirectAdmin 1.690 (early December 2025)?
I had reservations about this when it was announced and wanted to wait a while to see what issues popped up. I'm mostly concerned about the additional memory requirements that would be necessary to run a large amount of users with their own php-fpm master configuration. By my own accounts, it looks like an idle php-fpm master process is going to consume right at 20MB of memory. That might not seem like a lot, but for 200 users that's 4GB just to idle. 600 users it's 12GB - again, just idling.
But the lack of discussions on this topic would seem to indicate that a) A lot of administrators aren't using the setup b) the setup is working flawlessly with no issues or c) administrators that have this enabled have very few users on their servers and/or a lot of free RAM.
If I'm understanding how DirectAdmin does this setup (which I may have wrong), you can check the memory usage of an idle PHP by doing at:
systemctl status php-isolated-fpm84@%username%.service
for a user on the server that has no running PHP pool processes (whatever PHP version they are using). It will show how much memory an idle php-fpm master is using. Multiply this by the number of users on the server and that's how much memory is consumed just to hold idle php-fpm master processes for each user.
Maybe it's not as big of an issue as I would think.
I'm considering implementing something similar to this on our servers, but the memory constraints still bug me.
I'm just wondering how many server administrators are using this? How many ballpark users do you have on your servers? (less than 100? 200? 500? 1000?) and are you seeing any memory capacity issues?
I had reservations about this when it was announced and wanted to wait a while to see what issues popped up. I'm mostly concerned about the additional memory requirements that would be necessary to run a large amount of users with their own php-fpm master configuration. By my own accounts, it looks like an idle php-fpm master process is going to consume right at 20MB of memory. That might not seem like a lot, but for 200 users that's 4GB just to idle. 600 users it's 12GB - again, just idling.
But the lack of discussions on this topic would seem to indicate that a) A lot of administrators aren't using the setup b) the setup is working flawlessly with no issues or c) administrators that have this enabled have very few users on their servers and/or a lot of free RAM.
If I'm understanding how DirectAdmin does this setup (which I may have wrong), you can check the memory usage of an idle PHP by doing at:
systemctl status php-isolated-fpm84@%username%.service
for a user on the server that has no running PHP pool processes (whatever PHP version they are using). It will show how much memory an idle php-fpm master is using. Multiply this by the number of users on the server and that's how much memory is consumed just to hold idle php-fpm master processes for each user.
Maybe it's not as big of an issue as I would think.
I'm considering implementing something similar to this on our servers, but the memory constraints still bug me.
I'm just wondering how many server administrators are using this? How many ballpark users do you have on your servers? (less than 100? 200? 500? 1000?) and are you seeing any memory capacity issues?