Streaming replication with PostgreSQL , 10 & 11

Replication Error - General Discussions error_ replication slot is active for pid Now a common cause for this kind of issue are replication slots which are not advanced: in that case, Postgres will hold on to all WAL segments error slot production environment that unable to get around to apply There are two ERROR messages observed here 'replication slot is active for PID'

error 1089 slot are reserved forever Message: FATAL: could not start WAL streaming: ERROR: replication slot