Getting Exception : replication slot XXX is active for PID XXX` on

What is Replication slots in PostgreSQL Streaming error_ replication slot is active for pid The other application using the same configuration will show the following error message: replication slot slot_name is already active for PID x error 1089 ERROR: executing recovery, execution of command failed at 1st stage pid 28665: LOG: starting recovering node 0 > 10:04

error_ replication slot is active for pid slot are reserved forever Message: FATAL: could not start WAL streaming: ERROR: replication slot