Collector will not show Connected Polls or show Status post upgrade

Products

• Network Observability
• CA Performance Management

Issue/Introduction

After you upgrade a Data Collector, the collector fails to reconnect to the Data Aggregator. The collector does not show "Connected Polls" or its status in the Performance Manager GUI. You see a java.net.BindException: Address already in use error for port <port> in the logs, and the ActiveMQ service fails to start.

Environment

DX NetOps Performance Management 24.4.13

Cause

Port Conflict: Port mentioned in the above error is already occupied by an orphaned or existing process, preventing the Data Collector from initializing its JMXConnectorServer.

Resolution

To resolve this issue, you must clear the port conflict:

1. Identify and Clear the Port Conflict:

   • Run the command: netstat -anp | grep <port>
   • Note the Process ID (PID) associated with the port.
   • If the PID belongs to an old or orphaned collector process, terminate it using kill -9 ####.
   • Verify the port is free by running the netstat command again.

2. Restart Services:

   • Restart the Data Collector service using systemctl restart dcmd.
   • Verify that both the dcmd and activemq services are running using systemctl status dcmd activemq