Data Collector state is unknown and data is not being collected. Restart of the Data Collector and/or the Data Aggregator does not bring the Data Collector online.
The data collector will appear to be running and the command systemctl status dcmd will show running.
However the Data Aggregator is still unable to connect the to the Data Collector and the status remains unknown and no data is collected.
Data Collector status is unknown
1. Stop the Data Collector
/etc/init.d/dcmd stop (on Red Hat 6.x systems)
systemctl stop dcmd (on Red Hat 7.x systems)
2. Move the apache data directory.
mv /opt/IMDataCollector/apache-karaf-2.3.0/data /opt/IMDataCollector/apache-karaf-2.3.0/data.old
3. Start the data collector
/etc/init.d/dcmd start (on Red Hat 6.x systems)
systemctl start dcmd (on Red Hat 7.x systems)