Hammer ping is returning candlepin fails with 404 error message

Issue

• Hammer ping returns 404 error on candlepin

# hammer ping
candlepin:      
    Status:          FAIL
    Server Response:
candlepin_auth: 
    Status:          FAIL
    Server Response:
pulp:           
    Status:          ok
    Server Response: Duration: 40ms
foreman_tasks:  
    Status:          ok
    Server Response: Duration: 587ms

• Candlepin in failing as it is unable to PSQL DB and the satellite-installer --scenario satellite --upgrade also fails with following error in candlepin.log.

2018-11-06 13:07:55,763 [thread=Task-Thread-for-com.mchange.v2.async.ThreadPerTaskAsynchronousRunner@4c4f5d1] [=, org=] WARN  com.mchange.v2.resourcepool.BasicResourcePool - com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@43e45e75 -- Acquisition Attempt Failed!!! Clearing pending acquires. While trying to acquire a needed new resource, we failed to succeed more than the maximum number of allowed acquisition attempts (30). Last acquisition attempt exception: 
org.postgresql.util.PSQLException: The connection attempt failed.