DC not reporting in?

Products

• CA Infrastructure Management
• CA Performance Management - Usage and Administration
• DX NetOps

Issue/Introduction

Having an issue on a brand new install in which the Data collector DC is not reporting in to Data Aggregator DA . 

I looked in the configuration files where the Data Aggregator DA is set, and they're all right (pointing to the Data Aggregator DA). 

Data collector DC is running but not connecting to DA 

New Data collector DC not listed in DA

Environment

Release : 20.2

Component : IM Reporting / Admin / Configuration

Cause

Found this in the karaf.out 

Unable to update instance pid: Unable to find root instance in /opt/DataCollector/apache-karaf-2.4.3/instances/instance.properties

Stale configuration 

Resolution

Clear the old configuration data on the Data Collector DC 

service activemq stop
service dcmd stop 

cd /opt/PM/DataCollector/apache-karaf-2.4.3/
mv data data.bak 

cd /opt/PM/DataCollector/broker/apache-activemq-5.15.8
mv data data.bak

service activemq start 
service dcmd start