During some recent testing, we ran into a case where the monitor failed to restart. Looking at the logs after the fact (it was an automated test), the monitor died because it couldn't bind to 50095.
The likely problem is that the datanode or namenode happened to grab that port because it's in the ephemeral range which is commonly 32768-61000 (per wikipedia).
It would be good to give our ports a once-over and start to push towards better default values. This has been a problem for us for quite some time.