Various people have reported a similar problem: after some time of good operation, Openfire suddenly stops accepting new (TCP) client connections.
This problem was not happening in 4.6.3, but is happening in every version since 4.6.4.
A symptom seems to be that the "Sessions" admin console page shows "Invalid session/connection" for some sessions.
The log files show messages like these (which also are logged in servers that are not suffering from this problem - unsure if this is relevant):
So far, reproducing the problem is difficult. It happens occasionally (on some servers, only once or twice a day). No-one seems to be able to cause the problem at will.
A work-around for the problem:
- in the admin console page, navigate to Server > Server Settings > Client Connections
- disable "Plain-text (with STARTTLS) connections" by removing the check mark from the input box
- press the "Save Settings" button
- re-enable "Plain-text (with STARTTLS) connections" by adding a check mark in the input box
- press the "Save Settings" button again
This will effectively restart the connection listeners, which seems to work around the problem.
Another way to work around this issue is by restarting Openfire.