If you are running a large Atmail cluster with multiple machines, you can further optimize the performance of the application by tuning the systems sysctl values for networking. One common issue is on a highly loaded system, the max number of TCP connections can exceed between hosts, or too many connections are in the idle state.
- On-Premise Server + WebMail Installations: Version 6.0 > Current Version
- Heavy load
We recommend the following be applied to the /etc/sysctl.conf
Close connections in the TCP FIN timeout state 10 seconds ( default 60 )
Increase the range of ports available for client connections ( default 32768 61000 )
Server machines (e.g mysql server or main machine)
Same value as clients
The net.core.somaxconn value has an important role. It limits the maximum number of requests queued to a listen socket.
After editing the /etc/sysctl.conf you can reboot the machine, otherwise set the paramater directly on the CLI using:
This is just another tip for tuning the performance of an Atmail system, from the default stock Linux OS.