I noticed for the second time that, as time passes by (after one or two days), the reforger dedicated server process ends up using almost all memory (94%, check attachment) and ssh session becomes slow and later even impossible (ssh requests timeout). I have to restart server from the web management console.

See https://community.bistudio.com/wiki/Arma_Reforger:Server_Hosting :

As of 0.9.5 it is heavily recommended to use this startup parameter, set to a value in the 60..120 range; otherwise, the server can try to use all the available resources!
ArmaReforgerServer.exe -maxFPS 60

Have you tried lower it to 60?

I changed maxFPS from 120 to 60 and I notice the same behaviour : over less than 24 hours period the memory usage increases (eg from 5 GB to 12 GB as I write) although only one player connected to the game at the beginning of this period and no other players connected afterwards.

It looks to me as if the server process has a memory leak.

Should I fiddle around with a memory allocation parameter? What would be the recommended setup for Linux server?

UPDATE May 31st
In the end, setting maxFPS 60 doesn't change anything to the outcome (15GB memory used, logs indicating failed heartbeats and "Server not found" message when trying to join my dedicated server from the game)

Duplicate of T165158 ?
Remember to search for existing bugs before filing new ones!

Not duplicate, just read the title of this ticket. And yeah I searched before for existing tickets and didn't find yours because at that moment I wasn't aware of this memory leak problem (I discovered it afterwards).

Your ticket T165158 is a possible cause for my issue (memory leak => 'No server found' message)

So I linked this issue with yours as a 'subtask' which I understand is a possible 'cause task'.

Yesterday I patched the server to 0.9.5.61 version, emptied the .save folder, changed the mission to {1AEE808E7689FE54}Missions/23_Campaign_NWCoast.conf, restarted the server and launched the mission by connecting to the server then disconnected.

At the beginning the server CPU usage was pretty high compared to before the patching (>100% compared to <10%).
9 hours later error messages appear in the logs (again related to heartbeats but a bit different).
At the same time as the log error messages the CPU usage dropped to <1%, memory leaking stopped at 8GB and the server is not listed in the servers list anymore.

I noticed 2 new parameters in the server JSON config file and added them to server config, then restarted.
"a2sQueryEnabled": true,
"steamQueryPort": 17777

Some players (not more than 5) joined the server today and played about 1 hour before all of them lost connection with server at the same time.

After that point :

• the server was no longer listed in the server list
• I lost remote ssh connection to the server
• the Reforger server process was using only 9GB of RAM (well below the 16 GB limit)
• some errors related to Http request appeared in the logs (see attached logs since server last restart)

Sun 2022-06-05 22:26:38 UTC mace_reforger_van_alpha[20342]: BACKEND (E): Http Error (SEND)
Sun 2022-06-05 22:26:38 UTC mace_reforger_van_alpha[20342]: BACKEND (E): [RestApi] ID:[438] Error - Cannot send request
...
Sun 2022-06-05 22:27:23 UTC mace_reforger_van_alpha[20342]: BACKEND (E): [RestApi] ID:[439] Error - Cannot send request
Sun 2022-06-05 22:27:23 UTC mace_reforger_van_alpha[20342]: BACKEND (E): Http Error x-request-uid="1e6b0280-f3c1-4e35-9f34-881608b31076", apiCode="MpRoomNotFound", message="There is no room with id ar-steam"

The server was configurer with the property "dedicatedServerId": "ar-%profilename" which seems to generate "ar-steam" value found in the logs. So I set the property to empty string and restarted the server.

Any clue of what is going on?

Please do not parent unrelated issues to your own to try and raise the profile of your issues, it is disingenuous behaviour at best and entirely misleading for anyone following tracker issues!

My issue was a completely seperate issue reported to a developer on Discord who asked me to provide a feedback tracker ticket for it.

@Uro
You accuse me of trying to raise my ticket profile by linking unrelated issues which I deny
I related your issue since it looked like the root cause of the problem I am facing (memory leak => server not found in the server list)
Btw it is someone else who send me the link to your post because he also thought it was related to my issue.
If you don' want to link your issue to mine, fine with me but that won't help solve our issues which do seem related

Please next time refrain from accusations