I am running Icinga on Centos 8.2.2004, i’m seeing an issue where icinga is crashing each day and in icinga2.log it only says: critical/ApiListener: Cannot accept new connection: Too many open files
we have in our infrastructure the same issue. We running two Icinga2-servers (CentOS 7) with version icinga2-2.13.2-1 installed.
We increased the open file limit for the system to 65535
and under the /etc/sysconfig/icinga2 the RLIMIT also to 65535.
But increasing the file limits doesn´t solved the problem, because the openfiles only increase then to the next open file limit. After restart of icinga2-service the open files are cleaned, but only till the limit is reached again.
what we found out is that the established connections between the icinga-server and the clients are not closed.