Shows an error as in the screenshot.screen-shot-2016-05-05-at-21727-pm.png
A few things which can be checked:
1. netstat -an |grep 5432
The above should show 5432 as LISTEN
netstat -an | grep 5432 tcp 0 0 0.0.0.0:5432 0.0.0.0:* LISTEN tcp 0 0 10.243.52.22:5432 10.243.52.11:49502 ESTABLISHED tcp 0 0 :::5432 :::* LISTEN unix 2 [ ACC ] STREAM LISTENING 241663 /tmp/.s.PGSQL.5432
2. You should be able to telnet to the management server via this port.
telnet <management_server> 5432
3. Check the DB server health:
System state,
runtime - average load, disk utilization
static - CPU cores and memory
You may see the error as below if port 5432 is not open/accessible:
2016-04-28 13:40:13,832 org: env: main WARN i.a.a.s.a.ServerBootstrapService - ServerBootstrapServiceImpl$1$4.execute() : Exception occured while making a query: select pg_last_xlog_receive_location() Exception: Could not get JDBC Connection; nested exception is org.apache.commons.dbcp.SQLNestedException: Cannot create PoolableConnectionFactory (Connection refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections.)