In a recent downtime of policies in drools-pdp, it was observed that all the policies running in drools-pdp were removed after a restart of the pod.

After debugging and logs analysis it was found that drools-pdp sent the registration request to PAP immediately after restart and PAP actually registered the PDP and sent back the list of policies for deployment. But the "frankfurt" controller was not loaded yet. Leading to failure in deploying policies. 

Ideally drools-pdp must wait for all the supported controllers to be ready before sending the registration request to PAP. So that it is ready to load policies.

The fix has been already done in Guilin version - https://gerrit.onap.org/r/c/policy/drools-pdp/+/111665

So, the work will be to cherry pick the fix in Frankfurt version and release images for drools-pdp & drools-applications.