What is Replication slots in PostgreSQL Streaming

IBM PowerHA SystemMirror for i: Using DS8000 error_ replication slot is active for pid Failing to do so will make the replication slot stuck at its current position, the publisher node will start accumulating WALs and inevitably error 1089 To fix the error The replication slot replication_slot status is 'lost' Make sure that the slot is active and try again

error_ replication slot is active for pid ERROR: executing recovery, execution of command failed at 1st stage pid 28665: LOG: starting recovering node 0 > 10:04