Hi, I'm trying to address an issue in Debezium (DBZ-3823 <https://issues.redhat.com/browse/DBZ-3823>) where a source connector task cannot recover from a retriable exception.
The root cause is that the task interacts with the source database during SourceTask#start but Kafka Connect doesn't handle retriable exceptions thrown at this stage as retriable. KIP-298 <https://cwiki.apache.org/confluence/display/KAFKA/KIP-298%3A+Error+Handling+in+Connect> that originally introduced handling of retriable exception doesn't describe handling task start exceptions, so it's unclear to me whether those aren't allowed by design or it was just out of the scope of the KIP. My current working solution <https://github.com/debezium/debezium/pull/2572> relies on the internal Debezium implementation of the task restart which introduces certain risks (the details are in the PR description). The question is: are retriable exceptions during start disallowed by design, and the task must not throw retriable exceptions during start, or it's just currently not supported by the Connect framework and I just need to implement proper error handling in the connector? Thanks! -- Sergei Morozov
