Production node went down and is not reachable. Log file showing "Server connection failed".
Release : 6.9
Component : DOLLAR UNIVERSE
Following commands will help diagnosing the problem:
1) telnet <nodename> port
If the port is blocked then connection refused error is displayed in the log file.
2) netstat -an
which will show if the needed port/s are available and listen.
3) pinging back and forth with short name, long name and ip address will tell if there is anything wrong with the DNS server.
In addition to the above commands, the health status of the system server should also be checked to make sure disk space and enough memory is available to process the jobs.
If nothing else helps then the network team should set up traps and look for communication problems.