[skull]

Sorry no more ideas.

Use debug level on httpd and try to capture something useful on log.

[ctomc]

also try telneting to backend instance once this error happens.

Also make sure there is no IDS system in place that just starts dropping network connections at random.

to make sure if this is a network problem and not apache httpd / wildfly problem, I would suggest for test putting httpd into same network (or even same machine as one of the nodes) as the application servers and if everything works in this scenario you could eliminate problem with httpd / wildfly but focus on network.

Another option would be your VIP configuration and having problems once in a while.

Remembering how your network used to be configured (years ago) this could be possible.