[Bug]: Memory leaks and unexpected crashes

[Vyacheslav73195]

What system are you using?

Ubuntu 24.04

What version are you using?

app 2.5.1 / core 2.7.1

What went wrong?

At random moments, the panel freezes. Mongod crashes, clients cannot connect, and the web dashboard site cannot be accessed (error 502). The screenshots show the usual resource consumption, but at some point (there should be nothing high-load at this point), the server becomes very heavily loaded and crashes. Can you recommend something?

Any other helpful information?

No response

[Johnnybegood24]

The same issue (

[shogun-kub]

I have a similar issue, but I did not configure web panel or telegram bot, I only use text-based interface. The problem points out to mongodb, it randomly shuts down, but I have not found any meaningful explanation why. No OOM killer messages in dmesg and the last log messages also look normal, something about accepting connections.
That's the last part of my mongodb log:

{"t":{"$date":"2026-04-08T03:49:01.829+00:00"},"s":"I",  "c":"NETWORK",  "id":22944,   "ctx":"conn3","msg":"Connection ended","attr":{"remote":"127.0.0.1:41024","isLoadBalanced":false,"uuid":{"uuid":{"$uuid":"1fd54c7a-4c83-4694-8696-d0428432dc5c"}},"connectionId":3,"connectionCount":3}}
{"t":{"$date":"2026-04-08T03:49:01.829+00:00"},"s":"I",  "c":"NETWORK",  "id":22944,   "ctx":"conn2","msg":"Connection ended","attr":{"remote":"127.0.0.1:41020","isLoadBalanced":false,"uuid":{"uuid":{"$uuid":"e5dcc953-a4d9-4043-9076-dcb8c6215f4a"}},"connectionId":2,"connectionCount":2}}
{"t":{"$date":"2026-04-08T03:49:01.924+00:00"},"s":"I",  "c":"NETWORK",  "id":22944,   "ctx":"conn4","msg":"Connection ended","attr":{"remote":"127.0.0.1:41028","isLoadBalanced":false,"uuid":{"uuid":{"$uuid":"2ec34e26-9ea9-43d4-ad4d-3dbea111166c"}},"connectionId":4,"connectionCount":1}}
{"t":{"$date":"2026-04-08T03:49:08.580+00:00"},"s":"I",  "c":"NETWORK",  "id":22943,   "ctx":"listener","msg":"Connection accepted","attr":{"remote":"127.0.0.1:37144","isLoadBalanced":false,"uuid":{"uuid":{"$uuid":"293bab26-3761-417f-bc62-a539b8df7055"}},"connectionId":5,"connectionCount":2}}
{"t":{"$date":"2026-04-08T03:49:08.581+00:00"},"s":"I",  "c":"NETWORK",  "id":51800,   "ctx":"conn5","msg":"client metadata","attr":{"remote":"127.0.0.1:37144","client":"conn5","negotiatedCompressors":[],"doc":{"driver":{"name":"mongo-go-driver","version":"1.17.6"},"os":{"type":"linux","architecture":"amd64"},"platform":"go1.22.12"}}}
{"t":{"$date":"2026-04-08T03:49:08.581+00:00"},"s":"I",  "c":"ACCESS",   "id":10483900,"ctx":"conn5","msg":"Connection not authenticating","attr":{"client":"127.0.0.1:37144","doc":{"driver":{"name":"mongo-go-driver","version":"1.17.6"},"os":{"type":"linux","architecture":"amd64"},"platform":"go1.22.12"}}}

systemd status also seems not really useful:

# systemctl status mongod
× mongod.service - MongoDB Database Server
     Loaded: loaded (/lib/systemd/system/mongod.service; enabled; preset: enabled)
    Drop-In: /etc/systemd/system/mongod.service.d
             └─override.conf
     Active: failed (Result: signal) since Wed 2026-04-08 03:49:57 UTC; 9min ago
   Duration: 58.219s
       Docs: https://docs.mongodb.org/manual
    Process: 11526 ExecStart=/usr/bin/mongod --config /etc/mongod.conf (code=killed, signal=SEGV)
   Main PID: 11526 (code=killed, signal=SEGV)
        CPU: 2.346s

Apr 08 03:48:59 reserve-fin systemd[1]: Started mongod.service - MongoDB Database Server.
Apr 08 03:49:57 reserve-fin systemd[1]: mongod.service: Main process exited, code=killed, status=11/SEGV
Apr 08 03:49:57 reserve-fin systemd[1]: mongod.service: Failed with result 'signal'.
Apr 08 03:49:57 reserve-fin systemd[1]: mongod.service: Consumed 2.346s CPU time.

I thought it may be a bug in mongodb (8.0.20 in my case), but the same version seems to work properly in the similar system (Debian 12) with only 1GB of RAM, while this particular machine has 2GB.

At this point I ran out of ideas how to diagnose this issue properly.

[shogun-kub]

Looks like I've found my problem, maybe you have the same issue. My problem was in the installed xanmod kernel, in particular, in its bleeding edge version. Updated MongoDB package explicitly pointing this, instead of mysterious crashes:

Apr 14 06:35:25 reserve-fin systemd[1]: Started mongod.service - MongoDB Database Server.
Apr 14 06:35:25 reserve-fin mongod[117209]: {"t":{"$date":"2026-04-14T06:35:25.679Z"},"s":"F",  "c":"CONTROL",  "id":12257600,"ctx":"main","msg":"MongoDB cannot start: Linux kernel versions 6.19 and newer has a known incompatibility with this version of MongoDB. See https://jira.mongodb.org/browse/SERVER-121912 for more information."}
Apr 14 06:35:25 reserve-fin systemd[1]: mongod.service: Main process exited, code=exited, status=1/FAILURE
Apr 14 06:35:25 reserve-fin systemd[1]: mongod.service: Failed with result 'exit-code'.
-- Boot 3b128a3430a4491cbac10f456c3813a6 --
Apr 14 06:49:08 reserve-fin systemd[1]: Started mongod.service - MongoDB Database Server.
Apr 14 06:49:10 reserve-fin mongod[387]: {"t":{"$date":"2026-04-14T06:49:10.419Z"},"s":"I",  "c":"CONTROL",  "id":7484500, "ctx":"main","msg":"Environment variable MONGODB_CONFIG_OVERRIDE_NOFORK == 1, overriding \"processManagement.fork\" to false"}

The part before the reboot is with xanmod 6.19.x version. After seeing the message about "incompatibility" I downgraded the kernel to 6.18.19. Now it works, so maybe it will help someone.

From what I could find (the link in the log above shows 403 for me, but I don't know if it's because it is private or because I'm supposed "russian hacker") it could be a bug in TCMalloc, which MongoDB uses. So, looking forward for it being fixed.

If you use xanmod kernel (or another 6.19 kernel) on your proxy server, try kernel version downgrade as a workaround for now.

[shogun-kub]

@Vyacheslav73195 @Johnnybegood24 See above,