Too many open files

[jdknives]

Describe the bug
When running the dmsg server in production with a significant load for extended periods of time, the server eventually logs

Too many open files and will not accept new connections. The issue does not appear immediately when the usual threshold of ~2500 sessions is reached, but only after a week or two of operation which leads me to believe we are not closing connections correctly at some place. This issue can be mitigated by increasing the number of files that can be opened on the system itself.

Environment information:

• OS: Linux server, dmsg-server run in docker container

Steps to Reproduce
Reproduction of this issue would require

1. Simulating a large number of sessions to a single server running on a Linux host
2. Letting the server run for a while and deconnecting/reconnecting clients for a substantial amount of time