Kafka Connect is unable to recover from a closed connection

Symptoms

Kafka Connect is unable to recover after the connection is closed and restarted. You might see the following error is logged repeatedly in /usr/iop/current/kafka-broker/logs/connect.log file.

[2016-12-22 14:59:27,054] ERROR Failed to run query for table 
TimestampIncrementingTableQuerier{name='null', query='select * from ...... }: 
java.sql.SQLRecoverableException: Closed Connection (io.confluent.connect.jdbc.JdbcSourceTask:232)

Resolving the problem

To resolve this issue, restart the Kafka Connect Service from Ambari.

Important: If you restart the Network Performance Insight® database for any reason, monitor the logs and make sure to restart the Kafka Connect as well.