Physical replication slot created through patroni configuration has retained the wal beyond default max_wal_size = 1 GB

PostgreSQL Percona Distribution for PostgreSQL
1

We have created 3 node postgresql, patroni, etcd High Availability and Failover cluster. For this cluster, patroni configuration is as below -

namespace: ${NAMESPACE}
scope: ${SCOPE}
name: ${NODE_NAME}

restapi:
listen: 0.0.0.0:8008
connect_address: ${NODE_IP}:8008

etcd3:
host: ${NODE_IP}:2379

bootstrap:

this section will be written into Etcd:///config after initializing new cluster

dcs:
ttl: 30
loop_wait: 10
retry_timeout: 10
maximum_lag_on_failover: 1048576
slots:
percona_cluster_1:
type: physical

  postgresql:
      use_pg_rewind: true
      use_slots: true
      parameters:
          max_connections: 200
          wal_level: replica
          hot_standby: on
          wal_keep_segments: 10
          max_wal_senders: 5
          max_replication_slots: 10
          wal_log_hints: on
          logging_collector: 'on'

some desired options for ‘initdb’

initdb: # Note: It needs to be a list (some options need values, others are switches)

  • encoding: UTF8
  • data-checksums

pg_hba: # Add following lines to pg_hba.conf after running ‘initdb’

  • host replication replicator 127.0.0.1/32 trust
  • host replication replicator 0.0.0.0/0 md5
  • host all all 0.0.0.0/0 md5
  • host all all ::0/0 md5

Some additional users which needs to be created after initializing new cluster

users:
admin:
password: pwd123
options:

  • createrole
  • createdb
    percona:
    password: pwd123
    options:
  • createrole
  • createdb

postgresql:
cluster_name: cluster_1
listen: 0.0.0.0:5432
connect_address: ${NODE_IP}:5432
data_dir: ${DATA_DIR}
bin_dir: ${PG_BIN_DIR}
pgpass: /tmp/pgpass
authentication:
replication:
username: replicator
password: pwd987
superuser:
username: postgres
password: pwd789

parameters:
    unix_socket_directories: /var/run/postgresql/
create_replica_methods:
    - basebackup
basebackup:
    checkpoint: 'fast'

tags:
nofailover: false
noloadbalance: false
clonefrom: false
nosync: false

Cluster is running on this configuration. Physical replication slot named as “percona_cluster_1”, created in this patroni configuration has retained wal of size 3 TB and this slot is orphaned or inactive.

How to resolve this issue and prevent it from future occurance.