Setup multiple kafka connect sinks - jdbc

Question

I am working on streaming the data from postgreSQL to HDFS. I had setup confluent environment on HDP 2.6 sandbox. My jdbc source configs for postgreSQL are
name=jdbc_1
connector.class=io.confluent.connect.jdbc.JdbcSourceConnector
tasks.max=1
connection.url=jdbc:postgresql://host:port/db?currentSchema=schema&user=user&password=password
mode=timestamp
timestamp.column.name=col1
validate.non.null=false
topic.prefix=psql-
All other properties for connection are also fine and i am running it by
./bin/connect-standalone ./etc/kafka/connect-standalone.properties ./etc/kafka-connect-jdbc/source.properties
Its working fine and creating topics based on the number of tables in the database as
psql-table1
psql-table2
Now i want to run HDFS sinks on all the topics to create separate dir for every table in the postgreSQL database.
But when i run HDFS sink with command
./bin/connect-standalone ./etc/kafka/connect-standalone.properties ./etc/kafka-connect-hdfs/hdfs-postGres.properties
by running the source i am getting error
ERROR Stopping after connector error (org.apache.kafka.connect.cli.ConnectStandalone:113)
org.apache.kafka.connect.errors.ConnectException: Unable to start REST server
at org.apache.kafka.connect.runtime.rest.RestServer.start(RestServer.java:214)
at org.apache.kafka.connect.runtime.Connect.start(Connect.java:53)
at org.apache.kafka.connect.cli.ConnectStandalone.main(ConnectStandalone.java:95)
Caused by: java.net.BindException: Address already in use
at sun.nio.ch.Net.bind0(Native Method)
at sun.nio.ch.Net.bind(Net.java:433)
at sun.nio.ch.Net.bind(Net.java:425)
at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223)
at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74)
at org.eclipse.jetty.server.ServerConnector.openAcceptChannel(ServerConnector.java:331)
at org.eclipse.jetty.server.ServerConnector.open(ServerConnector.java:299)
at org.eclipse.jetty.server.AbstractNetworkConnector.doStart(AbstractNetworkConnector.java:80)
at org.eclipse.jetty.server.ServerConnector.doStart(ServerConnector.java:235)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
at org.eclipse.jetty.server.Server.doStart(Server.java:398)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
at org.apache.kafka.connect.runtime.rest.RestServer.start(RestServer.java:212)
... 2 more
and if i stop the source connection and start the sink it works fine.
Anyone can help me that how i can setup multiple sink connectors.

Answer 1

Kafka Connect starts a rest server on port 8083.
If you run more that one standalone connector on a single machine, you need to change it with the rest.port property
Or you can run connect-distributed, then POST your source and sink configurations individually as JSON payloads running on a single Connect server, then you wouldn't have this Address already in use issue.