TimeoutException: Timeout expired while fetching topic metadata [2024-03-29 121753,773] ERROR [Worker clientId=connect-2, groupId=A-mm2] Uncaught exception in herder work thread, exiting: (org.apache.kafka.connect.runtime.distributed.DistributedHerder:324) org.apache.kafka.common.errors.TimeoutException: Timeout expired while fetching topic metadata [2024-03-29 121753,775] INFO Kafka MirrorMaker stopping (org.apache.kafka.connect.mirror.MirrorMaker:184) [2024-03-29 121753,776] INFO [Worker clientId=connect-1, groupId=B-mm2] Herder stopping (org.apache.kafka.connect.runtime.distributed.DistributedHerder:718) [2024-03-29 121753,776] INFO [Worker clientId=connect-1, groupId=B-mm2] Stopping connectors and tasks that are still assigned to this worker. (org.apache.kafka.connect.runtime.distributed.DistributedHerder:683) [2024-03-29 121753,778] INFO Stopping connector MirrorHeartbeatConnector (org.apache.kafka.connect.runtime.Worker:387) [2024-03-29 121753,778] INFO Scheduled shutdown for WorkerConnector{id=MirrorHeartbeatConnector} (org.apache.kafka.connect.runtime.WorkerConnector:248) [2024-03-29 121753,778] INFO Stopping connector MirrorSourceConnector (org.apache.kafka.connect.runtime.Worker:387) [2024-03-29 121753,779] INFO Scheduled shutdown for WorkerConnector{id=MirrorSourceConnector} (org.apache.kafka.connect.runtime.WorkerConnector:248) [2024-03-29 121753,779] INFO Stopping connector MirrorCheckpointConnector (org.apache.kafka.connect.runtime.Worker:387) [2024-03-29 121753,782] INFO Scheduled shutdown for WorkerConnector{id=MirrorCheckpointConnector} (org.apache.kafka.connect.runtime.WorkerConnector:248) [2024-03-29 121753,784] INFO Completed shutdown for WorkerConnector{id=MirrorCheckpointConnector} (org.apache.kafka.connect.runtime.WorkerConnector:268) [2024-03-29 121753,785] INFO Completed shutdown for WorkerConnector{id=MirrorSourceConnector} (org.apache.kafka.connect.runtime.WorkerConnector:268) [2024-03-29 121753,792] INFO Completed shutdown for WorkerConnector{id=MirrorHeartbeatConnector} (org.apache.kafka.connect.runtime.WorkerConnector:268) [2024-03-29 121753,792] INFO Stopping task MirrorHeartbeatConnector-0 (org.apache.kafka.connect.runtime.Worker:836) The mirror maker connect configuration is usual for replication from cluster A to cluster B unidirectionally. Earlier the replication was working but now am facing this error. The issue isn't related to SASL or JDK, have checked that. No SSL protocol is implemented, have used PLAINTEXT in conf. Please help resolve. @Xiang Fu Can you please help?

from where you run MirrorMaker, have you tried the connection from source or dest kafka cluster?

Is this a Pinot related issue? I searched the log but didn't find a Pinot related log

no, this is pure Kafka issue