DA Services sometimes fails to respond to requests on 8581 port due to internal services issue.
Please follow the below steps inorder to resolve this
service dadaemon stop
mv /opt/IMDataAggregator/apache-karaf-2.3.0/data /opt/IMDataAggregator/apache-karaf-2.3.0/data_old
rm –rf /opt/IMDataAggregator/apache-karaf-2.3.0/data
service dadaemon start.
If the problem still persists after running above commands or if you face any additional problems during above commands, please contact CA Support.