"Communication error with the OPMN server local port" When Starting OPMN

The Problem

When attempting to start the OPMN services the following error occurs:

opmnctl: starting opmn and all managed processes...
"Communication error with the OPMN server local port. Check the OPMN log files"

The Solution

Another opmn.exe process was using the port configured for OPMN.

1. Check the PORT defined for OPMN in %ORACLE_HOME%\opmn\conf\opmn.xml. Example: port local=“6101”.

2. Execute the following from the DOS Prompt:

netstat -ano

3. Results of ‘netstat -ano’ show something similar to the following:

Active Connections

Proto Local Address  Foreign Address State     PID
TCP   0.0.0.0:80     0.0.0.0:0       LISTENING 4692
TCP   0.0.0.0:135    0.0.0.0:0       LISTENING 708
TCP   0.0.0.0:443    0.0.0.0:0       LISTENING 1928
...
TCP   127.0.0.1:6101 0.0.0.0:0       LISTENING 1376

In this example, port 6101 is LISTENING using Process ID (PID) 1376.

Now follow the stpes outlined below:

1. Log into the Application Server as a user with admin privileges.

2. Open a DOS prompt and execute the following:

netstat -ano

3. Make of note of the PID currently assigned to port 6101. For example:

TCP 127.0.0.1:6101 0.0.0.0:0 LISTENING 5364

Where 5364 in this case is the PID.

4. Using Windows Task Manager, Kill the Process associated with the PID.

5. Start opmn using ‘opmnctl start’:

opmnctl start