I am also encountering the same issues (HTTP Error 503 when trying to access the Falcon web UI and Ambari Service Check for Falcon is consistently failing). HDP 2.5.3.0-37, Ambari 2.4.2.0-136, Falcon 0.10.0.2.5.3.0-37 installed on SLES 11 SP3 This problem didn't occur when the cluster was installed with HDP 2.5.0.2 and Ambari 2.4.1.0. I've opened the following Apache JIRA for the Ambari project for this issue: https://issues.apache.org/jira/browse/AMBARI-19370 Excerpts from the falcon.application.log: 2017-01-04 14:08:56,436 ERROR - [main:] ~ Failed to initialize service org.apache.falcon.metadata.MetadataMappingService (ServiceInitializer:49) java.lang.RuntimeException: GraphFactory could not instantiate this Graph implementation [com.thinkaurelius.titan.core.TitanFactory]. 2017-01-04 14:08:56,438 ERROR - [main:] ~ Failed startup of context org.mortbay.jetty.webapp.WebAppContext@96a75da{/,/usr/hdp/current/falcon-server/server/webapp/falcon} (log:87) java.lang.RuntimeException: org.apache.falcon.FalconException: java.lang.RuntimeException: GraphFactory could not instantiate this Graph implementation [com.thinkaurelius.titan.core.TitanFactory]. ... View more