/etc/init.d/ambari-server start REASON: Server not yet listening on http port 8080 after 50 seconds. Exiting.

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The following error just indicates that your Ambari Server is taking salightly more than default 50 Seconds time to open port 8080 and hence you see this message.

ERROR: Exiting with exit code 1.
REASON: Server not yet listening on http port 8080 after 50 seconds. Exiting.

You should try the following to fix this:

Edit the "/etc/ambari-server/conf/ambari.properties" and increase the following property value to 120 or 150 seconds.

server.startup.web.timeout=120 

Then restart the ambari-server again.

# ambari-server restart