Unable to accept incoming connection (24 Too many open files)

[pvo]

After I increased the number of monitored Nodes via one proxy agent, I see lot of following messages in the agent log:

2020.12.28 13:23:52.562 *E* [                   ] Unable to accept incoming connection (24 Too many open files)
2020.12.28 13:23:53.066 *E* [                   ] Unable to accept incoming connection (24 Too many open files)
2020.12.28 13:23:56.570 *E* [                   ] Unable to accept incoming connection (24 Too many open files)

I've tried to increase the operating system value for max number of open file descriptors but even the value 65535 is not sufficient.

The CPU usage and other parameters of the proxy agent and server are OK.
I use some SNMP DCIs for and some script DCIs which start Agent actions on the proxy agent, but the number of DCIs is lower than 65535.

Objects............: 4404
Monitored nodes....: 1221 (approximately 900 via this proxy agent)
Collectible DCIs...: 14683

What does this message mean?
Is there any possibility to solve the problem?

[victor]

Hi,

try to check with lsof how many file descriptors actually open. It could be descriptor leak. Also, are you sure that your changes in open file limit actually reflected on nxagentd process? If it is being started with systemd you may need to make changes to unit file.

Best regards,
Victor

[pvo]

Hi Victor,

the systemd setting was the problem.

Thank you.