[yugabyte/yugabyte-db#30391] Handle NPE in isBeforeImageEnabled when using Logical Replication

[bakul-gupta]

Jira Link: DB-20273

Description

While validating gRPC connector support for Logical Replication (using a replication slot + publication instead of a stream created via yb-admin), the connector crashes during initialization with a NullPointerException in YBClientUtils.isBeforeImageEnabled().

Error while trying to get before image status
java.lang.NullPointerException
  at io.debezium.connector.yugabytedb.YBClientUtils.isBeforeImageEnabled(YBClientUtils.java:347)
  at io.debezium.connector.yugabytedb.YugabyteDBgRPCConnector.taskConfigs(YugabyteDBgRPCConnector.java:167)

Solution

When using a replication slot + publication instead of a yb-admin stream, the CDC stream options may not contain a record_type key, causing cdcStreamInfo.getOptions().get("record_type") to return null and the subsequent .equals() call to throw an NPE. Added a null check in YBClientUtils.isBeforeImageEnabled() — if record_type is missing, log a warning and return false (before image disabled).

[Sumukh-Phalgaonkar]

Can you add a UT which would fail without your fix and validate that the fix works

[Sumukh-Phalgaonkar]

What happens when the user wants before image with a gRPC stream that has replication slot assiociated with it.

[bakul-gupta]

Setting the before image to true fixes the case you are talking about. And when the table has a replica identity say default then the before image is sent as null even though the flag is true as the message received does not have a before image.