kafka-connect-jdbc strange behavior with Oracle

[Simona Ramanauskaitė]

Hi,

i tried kafka-connect-jdbc with different databases and it works, however when I use Oracle database i get no results as well as errors.

It is strange as if i provide incorrect logins - i get an error, however if the logins are correct - there is no errors and the window freezes (i can not terminate the process, no topics are created etc.). 

I tries to turn debug mode, however there is no results. So i changed the kafka-connect-jdbc sources and notices i go through methods public String version() -> public ConfigDef config() and then nothing (I do not reach call of public void start(Map<String, String> properties)). 

So it seems like there are some issues with the configurations, however there is no error messages as well the properties file looks correct to me. There is the oracle.properties code:

name=abc
connector.class=io.confluent.connect.jdbc.JdbcSourceConnector
tasks.max=1
connection.url=jdbc:oracle:thin:@localhost:1521:databasename
connection.user=SYSTEM
connection.password=password
mode=bulk
topic.prefix=abc-

I am using Windws OS, so I call it like this:

bin/windows/connect-standalone.bat etc/schema-registry/connect-avro-standalone.properties etc/kafka-connect-jdbc/oracle.properties

The result after executing the code:

PATH_IN_MY_COMPUTER/bin/../share/java
confluent-common
kafka-serde-tools
monitoring-interceptors
kafka-connect-elasticsearch
VERSIJA
Oct 23, 2017 8:16:27 PM org.glassfish.jersey.internal.Errors logErrors
WARNING: The following warnings have been detected: WARNING: The (sub)resource method listConnectors in org.apache.kafka.connect.runtime.rest.resources.ConnectorsResource contains empty path annotation.
WARNING: The (sub)resource method createConnector in org.apache.kafka.connect.runtime.rest.resources.ConnectorsResource contains empty path annotation.
WARNING: The (sub)resource method listConnectorPlugins in org.apache.kafka.connect.runtime.rest.resources.ConnectorPluginsResource contains empty path annotation.
WARNING: The (sub)resource method serverInfo in org.apache.kafka.connect.runtime.rest.resources.RootResource contains empty path annotation.

AND THEN THESE IS NOTHING ELSE - FROZEN IN THIS POINT

Everything else is the same as using mysql or other database management systems

For your information - i am able to login the the database with the same logins through sqlplus.

Any ideas what can be wrong? What should i change to fix this?

[Simona Ramanauskaitė]

I tried another oracle database and it works fine. So the problem is related to database connection (but it is strange as i am able to connect to the database as well there is no errors).