I am attempting to connect to an Oracle database with Logstash 5.4.1 on CentOS 7.x. I have the Oracle driver on the machine as well, ojdbc7.jar.
When I execute logstash manually to test things, the config appears to be OK, but Logstash just sits there "Pushing flush onto pipeline" until I kill the logstash java process. It doesn't appear to provide any debug information regarding the connection to the Oracle database, or it's success or failure on executing the query. I'm a bit lost on what to try next. It most definitely is not creating any new indices on the elasticsearch cluster, and it doesn't even appear to be connecting to the db (but I have no way to validate this, except through logstash logs)