From 4472844aceb9d456f244fad891fb742179670ba3 Mon Sep 17 00:00:00 2001
From: Saurov Chandra Biswas
 <48715910+souravbiswassanto@users.noreply.github.com>
Date: Fri, 15 Mar 2024 21:14:43 +0600
Subject: [PATCH] Add support for postgres replication slot (#31)

Signed-off-by: souravbiswassanto <saurov@appscode.com>
---
 role_scripts/10/primary/start.sh          |  9 ++++--
 role_scripts/10/standby/ha_backup_job.sh  | 10 ++++--
 role_scripts/10/standby/run.sh            | 33 ++++++++++++++++++--
 role_scripts/10/standby/warm_stanby.sh    |  9 ++++--
 role_scripts/11/primary/start.sh          |  9 ++++--
 role_scripts/11/standby/ha_backup_job.sh  |  9 ++++--
 role_scripts/11/standby/run.sh            | 32 +++++++++++++++++--
 role_scripts/11/standby/warm_stanby.sh    |  9 ++++--
 role_scripts/12/primary/start.sh          |  9 ++++--
 role_scripts/12/standby/ha_backup_job.sh  | 12 ++++++-
 role_scripts/12/standby/run.sh            | 37 +++++++++++++++++++++-
 role_scripts/12/standby/warm_stanby.sh    | 12 ++++++-
 role_scripts/13/primary/start.sh          |  9 ++++--
 role_scripts/13/standby/ha_backup_job.sh  | 12 ++++++-
 role_scripts/13/standby/run.sh            | 37 ++++++++++++++++++++--
 role_scripts/13/standby/warm_stanby.sh    | 13 ++++++--
 role_scripts/14/primary/start.sh          |  9 ++++--
 role_scripts/14/standby/ha_backup_job.sh  | 13 ++++++--
 role_scripts/14/standby/run.sh            | 37 ++++++++++++++++++++--
 role_scripts/14/standby/warm_stanby.sh    | 13 ++++++--
 role_scripts/15/primary/start.sh          |  9 ++++--
 role_scripts/15/standby/ha_backup_job.sh  | 13 ++++++--
 role_scripts/15/standby/remote-replica.sh | 13 ++++++--
 role_scripts/15/standby/run.sh            | 37 ++++++++++++++++++++--
 role_scripts/15/standby/warm_stanby.sh    | 13 ++++++--
 role_scripts/16/primary/start.sh          |  9 ++++--
 role_scripts/16/standby/ha_backup_job.sh  | 13 ++++++--
 role_scripts/16/standby/remote-replica.sh | 13 ++++++--
 role_scripts/16/standby/run.sh            | 38 +++++++++++++++++++++--
 role_scripts/16/standby/warm_stanby.sh    | 13 ++++++--
 role_scripts/9/primary/start.sh           |  9 ++++--
 role_scripts/9/standby/ha_backup_job.sh   |  9 +++++-
 role_scripts/9/standby/run.sh             | 32 +++++++++++++++++--
 role_scripts/9/standby/warm_stanby.sh     |  8 ++++-
 scripts/config_recovery.conf.sh           |  4 +++
 scripts/restore.sh                        |  7 +++--
 36 files changed, 508 insertions(+), 65 deletions(-)

diff --git a/role_scripts/10/primary/start.sh b/role_scripts/10/primary/start.sh
index 48d337d..6a1d344 100755
--- a/role_scripts/10/primary/start.sh
+++ b/role_scripts/10/primary/start.sh
@@ -20,8 +20,13 @@ echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
 
-echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf
-
+#echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_segments = 64" >>/tmp/postgresql.conf
+fi
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 echo "archive_mode = always" >>/tmp/postgresql.conf
 echo "archive_command = '/bin/true'" >>/tmp/postgresql.conf
diff --git a/role_scripts/10/standby/ha_backup_job.sh b/role_scripts/10/standby/ha_backup_job.sh
index 8b09690..f754665 100755
--- a/role_scripts/10/standby/ha_backup_job.sh
+++ b/role_scripts/10/standby/ha_backup_job.sh
@@ -77,9 +77,15 @@ touch /tmp/postgresql.conf
 echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
-echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf
-echo "shared_preload_libraries = 'pg_stat_statements'" >>/tmp/postgresql.conf
+#echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_segments = 64" >>/tmp/postgresql.conf
+fi
 
+echo "shared_preload_libraries = 'pg_stat_statements'" >>/tmp/postgresql.conf
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 
 echo "archive_mode = always" >>/tmp/postgresql.conf
diff --git a/role_scripts/10/standby/run.sh b/role_scripts/10/standby/run.sh
index b24c801..ec71e58 100755
--- a/role_scripts/10/standby/run.sh
+++ b/role_scripts/10/standby/run.sh
@@ -66,6 +66,30 @@ while true; do
     sleep 2
 done
 
+if [[ "$WAL_LIMIT_POLICY" == "ReplicationSlot" ]]; then
+  CLEAN_HOSTNAME="${HOSTNAME//[^[:alnum:]]/}"
+  while true; do
+      echo "Create replication slot on primary"
+      if [[ "${SSL:-0}" == "ON" ]]; then
+          output=$(psql -h "$PRIMARY_HOST" --username=postgres "sslmode=$SSL_MODE sslrootcert=/tls/certs/client/ca.crt sslcert=/tls/certs/client/client.crt sslkey=/tls/certs/client/client.key" --command="SELECT pg_create_physical_replication_slot('${CLEAN_HOSTNAME}', true);" 2>&1 || true)
+      else
+          output=$(psql -h "$PRIMARY_HOST" --username=postgres --no-password --command="SELECT pg_create_physical_replication_slot('${CLEAN_HOSTNAME}', true);" 2>&1 || true)
+      fi
+      # check if current pod became leader itself
+
+      if [[ $output == *"(1 row)"* || $output == *"already exists"* ]]; then
+        break
+      fi
+
+      if [[ -e "/run_scripts/tmp/pg-failover-trigger" ]]; then
+          echo "Postgres promotion trigger_file found. Running primary run script"
+          /run_scripts/role/run.sh
+      fi
+      sleep 2
+  done
+fi
+
+
 if [[ ! -e "$PGDATA/PG_VERSION" ]]; then
     echo "take base basebackup..."
     # get basebackup
@@ -91,14 +115,19 @@ touch /tmp/postgresql.conf
 echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
-echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf
+#echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_segments = 64" >>/tmp/postgresql.conf
+fi
 
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 
 echo "archive_mode = always" >>/tmp/postgresql.conf
 echo "archive_command = '/bin/true'" >>/tmp/postgresql.conf
 echo "shared_preload_libraries = 'pg_stat_statements'" >>/tmp/postgresql.conf
-
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 if [ "$STANDBY" == "hot" ]; then
     echo "hot_standby = on" >>/tmp/postgresql.conf
 fi
diff --git a/role_scripts/10/standby/warm_stanby.sh b/role_scripts/10/standby/warm_stanby.sh
index d6fff1f..598ad68 100755
--- a/role_scripts/10/standby/warm_stanby.sh
+++ b/role_scripts/10/standby/warm_stanby.sh
@@ -22,8 +22,13 @@ touch /tmp/postgresql.conf
 echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
-echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf
-
+#echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_segments = 64" >>/tmp/postgresql.conf
+fi
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 
 echo "archive_mode = always" >>/tmp/postgresql.conf
diff --git a/role_scripts/11/primary/start.sh b/role_scripts/11/primary/start.sh
index 1f3c181..dde2bfa 100755
--- a/role_scripts/11/primary/start.sh
+++ b/role_scripts/11/primary/start.sh
@@ -20,8 +20,13 @@ echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
 
-echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf
-
+# echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_segments = 64" >>/tmp/postgresql.conf
+fi
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 echo "archive_mode = always" >>/tmp/postgresql.conf
 
diff --git a/role_scripts/11/standby/ha_backup_job.sh b/role_scripts/11/standby/ha_backup_job.sh
index f2b0f71..d337953 100755
--- a/role_scripts/11/standby/ha_backup_job.sh
+++ b/role_scripts/11/standby/ha_backup_job.sh
@@ -77,8 +77,13 @@ touch /tmp/postgresql.conf
 echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
-echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf
-
+# echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_segments = 64" >>/tmp/postgresql.conf
+fi
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 
 echo "archive_mode = always" >>/tmp/postgresql.conf
diff --git a/role_scripts/11/standby/run.sh b/role_scripts/11/standby/run.sh
index 1ae0b69..c2396f5 100755
--- a/role_scripts/11/standby/run.sh
+++ b/role_scripts/11/standby/run.sh
@@ -66,6 +66,29 @@ while true; do
     sleep 2
 done
 
+if [[ "$WAL_LIMIT_POLICY" == "ReplicationSlot" ]]; then
+  CLEAN_HOSTNAME="${HOSTNAME//[^[:alnum:]]/}"
+  while true; do
+      echo "Create replication slot on primary"
+      if [[ "${SSL:-0}" == "ON" ]]; then
+          output=$(psql -h "$PRIMARY_HOST" --username=postgres "sslmode=$SSL_MODE sslrootcert=/tls/certs/client/ca.crt sslcert=/tls/certs/client/client.crt sslkey=/tls/certs/client/client.key" --command="SELECT pg_create_physical_replication_slot('${CLEAN_HOSTNAME}', true);" 2>&1 || true)
+      else
+          output=$(psql -h "$PRIMARY_HOST" --username=postgres --no-password --command="SELECT pg_create_physical_replication_slot('${CLEAN_HOSTNAME}', true);" 2>&1 || true)
+      fi
+      # check if current pod became leader itself
+
+      if [[ $output == *"(1 row)"* || $output == *"already exists"* ]]; then
+        break
+      fi
+
+      if [[ -e "/run_scripts/tmp/pg-failover-trigger" ]]; then
+          echo "Postgres promotion trigger_file found. Running primary run script"
+          /run_scripts/role/run.sh
+      fi
+      sleep 2
+  done
+fi
+
 if [[ ! -e "$PGDATA/PG_VERSION" ]]; then
     echo "take base basebackup..."
     # get basebackup
@@ -91,8 +114,13 @@ touch /tmp/postgresql.conf
 echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
-echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf
-
+# echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_segments = 64" >>/tmp/postgresql.conf
+fi
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 
 echo "archive_mode = always" >>/tmp/postgresql.conf
diff --git a/role_scripts/11/standby/warm_stanby.sh b/role_scripts/11/standby/warm_stanby.sh
index 4c890b9..b29d984 100755
--- a/role_scripts/11/standby/warm_stanby.sh
+++ b/role_scripts/11/standby/warm_stanby.sh
@@ -22,8 +22,13 @@ touch /tmp/postgresql.conf
 echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
-echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf
-
+# echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_segments = 64" >>/tmp/postgresql.conf
+fi
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 
 echo "archive_mode = always" >>/tmp/postgresql.conf
diff --git a/role_scripts/12/primary/start.sh b/role_scripts/12/primary/start.sh
index e91b78e..e85c9c9 100755
--- a/role_scripts/12/primary/start.sh
+++ b/role_scripts/12/primary/start.sh
@@ -20,8 +20,13 @@ echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
 
-echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf
-
+# echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_segments = 64" >>/tmp/postgresql.conf
+fi
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 
 # we are not doing any archiving by default but it's better to have this config in our postgresql.conf file in case of customization.
diff --git a/role_scripts/12/standby/ha_backup_job.sh b/role_scripts/12/standby/ha_backup_job.sh
index ef0fe8c..def35a0 100755
--- a/role_scripts/12/standby/ha_backup_job.sh
+++ b/role_scripts/12/standby/ha_backup_job.sh
@@ -72,8 +72,18 @@ echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
 
-echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
+#echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_segments = 64" >>/tmp/postgresql.conf
+fi
 
+if [[ "$WAL_LIMIT_POLICY" == "ReplicationSlot" ]]; then
+  CLEAN_HOSTNAME="${HOSTNAME//[^[:alnum:]]/}"
+  echo "primary_slot_name = "$CLEAN_HOSTNAME"" >>/tmp/postgresql.conf
+fi
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 
 # we are not doing any archiving by default but it's better to have this config in our postgresql.conf file in case of customization.
diff --git a/role_scripts/12/standby/run.sh b/role_scripts/12/standby/run.sh
index fa54385..958c671 100755
--- a/role_scripts/12/standby/run.sh
+++ b/role_scripts/12/standby/run.sh
@@ -66,6 +66,30 @@ while true; do
     sleep 2
 done
 
+if [[ "$WAL_LIMIT_POLICY" == "ReplicationSlot" ]]; then
+  CLEAN_HOSTNAME="${HOSTNAME//[^[:alnum:]]/}"
+  while true; do
+      echo "Create replication slot on primary"
+      if [[ "${SSL:-0}" == "ON" ]]; then
+          output=$(psql -h "$PRIMARY_HOST" --username=postgres "sslmode=$SSL_MODE sslrootcert=/tls/certs/client/ca.crt sslcert=/tls/certs/client/client.crt sslkey=/tls/certs/client/client.key" --command="SELECT pg_create_physical_replication_slot('${CLEAN_HOSTNAME}', true);" 2>&1 || true)
+      else
+          output=$(psql -h "$PRIMARY_HOST" --username=postgres --no-password --command="SELECT pg_create_physical_replication_slot('${CLEAN_HOSTNAME}', true);" 2>&1 || true)
+      fi
+      # check if current pod became leader itself
+
+      if [[ $output == *"(1 row)"* || $output == *"already exists"* ]]; then
+        break
+      fi
+
+      if [[ -e "/run_scripts/tmp/pg-failover-trigger" ]]; then
+          echo "Postgres promotion trigger_file found. Running primary run script"
+          /run_scripts/role/run.sh
+      fi
+      sleep 2
+  done
+fi
+
+
 if [[ ! -e "$PGDATA/PG_VERSION" ]]; then
     echo "take base basebackup..."
     mkdir -p "$PGDATA"
@@ -86,7 +110,18 @@ echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
 
-echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
+# echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_segments = 64" >>/tmp/postgresql.conf
+fi
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
+if [[ "$WAL_LIMIT_POLICY" == "ReplicationSlot" ]]; then
+  CLEAN_HOSTNAME="${HOSTNAME//[^[:alnum:]]/}"
+  echo "primary_slot_name = "$CLEAN_HOSTNAME"" >>/tmp/postgresql.conf
+fi
+
 
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 
diff --git a/role_scripts/12/standby/warm_stanby.sh b/role_scripts/12/standby/warm_stanby.sh
index 9e48786..56c1f2a 100755
--- a/role_scripts/12/standby/warm_stanby.sh
+++ b/role_scripts/12/standby/warm_stanby.sh
@@ -20,7 +20,17 @@ echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
 
-echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
+# echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_segments = 64" >>/tmp/postgresql.conf
+fi
+if [[ "$WAL_LIMIT_POLICY" == "ReplicationSlot" ]]; then
+  CLEAN_HOSTNAME="${HOSTNAME//[^[:alnum:]]/}"
+  echo "primary_slot_name = "$CLEAN_HOSTNAME"" >>/tmp/postgresql.conf
+fi
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 
diff --git a/role_scripts/13/primary/start.sh b/role_scripts/13/primary/start.sh
index 608825a..07b4307 100755
--- a/role_scripts/13/primary/start.sh
+++ b/role_scripts/13/primary/start.sh
@@ -20,8 +20,13 @@ echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
 
-echo "wal_keep_size = 1024" >>/tmp/postgresql.conf
-
+# echo "wal_keep_size = 1024" >>/tmp/postgresql.conf
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_segments = 64" >>/tmp/postgresql.conf
+fi
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 
 # we are not doing any archiving by default but it's better to have this config in our postgresql.conf file in case of customization.
diff --git a/role_scripts/13/standby/ha_backup_job.sh b/role_scripts/13/standby/ha_backup_job.sh
index f7e5e31..88692a1 100755
--- a/role_scripts/13/standby/ha_backup_job.sh
+++ b/role_scripts/13/standby/ha_backup_job.sh
@@ -72,7 +72,17 @@ echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
 
-echo "wal_keep_size = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
+# echo "wal_keep_size = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_size = 1024" >>/tmp/postgresql.conf
+fi
+if [[ "$WAL_LIMIT_POLICY" == "ReplicationSlot" ]]; then
+  CLEAN_HOSTNAME="${HOSTNAME//[^[:alnum:]]/}"
+  echo "primary_slot_name = "$CLEAN_HOSTNAME"" >>/tmp/postgresql.conf
+fi
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 
diff --git a/role_scripts/13/standby/run.sh b/role_scripts/13/standby/run.sh
index ef9a57f..507a8d2 100755
--- a/role_scripts/13/standby/run.sh
+++ b/role_scripts/13/standby/run.sh
@@ -66,6 +66,30 @@ while true; do
     sleep 2
 done
 
+if [[ "$WAL_LIMIT_POLICY" == "ReplicationSlot" ]]; then
+  CLEAN_HOSTNAME="${HOSTNAME//[^[:alnum:]]/}"
+  while true; do
+      echo "Create replication slot on primary"
+      if [[ "${SSL:-0}" == "ON" ]]; then
+          output=$(psql -h "$PRIMARY_HOST" --username=postgres "sslmode=$SSL_MODE sslrootcert=/tls/certs/client/ca.crt sslcert=/tls/certs/client/client.crt sslkey=/tls/certs/client/client.key" --command="SELECT pg_create_physical_replication_slot('${CLEAN_HOSTNAME}', true);" 2>&1 || true)
+      else
+          output=$(psql -h "$PRIMARY_HOST" --username=postgres --no-password --command="SELECT pg_create_physical_replication_slot('${CLEAN_HOSTNAME}', true);" 2>&1 || true)
+      fi
+      # check if current pod became leader itself
+
+      if [[ $output == *"(1 row)"* || $output == *"already exists"* ]]; then
+        break
+      fi
+
+      if [[ -e "/run_scripts/tmp/pg-failover-trigger" ]]; then
+          echo "Postgres promotion trigger_file found. Running primary run script"
+          /run_scripts/role/run.sh
+      fi
+      sleep 2
+  done
+fi
+
+
 if [[ ! -e "$PGDATA/PG_VERSION" ]]; then
     echo "take base basebackup..."
     mkdir -p "$PGDATA"
@@ -86,8 +110,17 @@ echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
 
-echo "wal_keep_size = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
-
+# echo "wal_keep_size = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_size = 1024" >>/tmp/postgresql.conf
+fi
+if [[ "$WAL_LIMIT_POLICY" == "ReplicationSlot" ]]; then
+  CLEAN_HOSTNAME="${HOSTNAME//[^[:alnum:]]/}"
+  echo "primary_slot_name = "$CLEAN_HOSTNAME"" >>/tmp/postgresql.conf
+fi
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 
 # we are not doing any archiving by default but it's better to have this config in our postgresql.conf file in case of customization.
diff --git a/role_scripts/13/standby/warm_stanby.sh b/role_scripts/13/standby/warm_stanby.sh
index e7a02ca..a06c212 100755
--- a/role_scripts/13/standby/warm_stanby.sh
+++ b/role_scripts/13/standby/warm_stanby.sh
@@ -20,8 +20,17 @@ echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
 
-echo "wal_keep_size = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
-
+# echo "wal_keep_size = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_size = 1024" >>/tmp/postgresql.conf
+fi
+if [[ "$WAL_LIMIT_POLICY" == "ReplicationSlot" ]]; then
+  CLEAN_HOSTNAME="${HOSTNAME//[^[:alnum:]]/}"
+  echo "primary_slot_name = "$CLEAN_HOSTNAME"" >>/tmp/postgresql.conf
+fi
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 
 # we are not doing any archiving by default but it's better to have this config in our postgresql.conf file in case of customization.
diff --git a/role_scripts/14/primary/start.sh b/role_scripts/14/primary/start.sh
index 19b7489..8e744bd 100755
--- a/role_scripts/14/primary/start.sh
+++ b/role_scripts/14/primary/start.sh
@@ -20,8 +20,13 @@ echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
 
-echo "wal_keep_size = 1024" >>/tmp/postgresql.conf
-
+# echo "wal_keep_size = 1024" >>/tmp/postgresql.conf
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_size = 1024" >>/tmp/postgresql.conf
+fi
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 
 # we are not doing any archiving by default but it's better to have this config in our postgresql.conf file in case of customization.
diff --git a/role_scripts/14/standby/ha_backup_job.sh b/role_scripts/14/standby/ha_backup_job.sh
index 6ca5d3e..ed26ce3 100755
--- a/role_scripts/14/standby/ha_backup_job.sh
+++ b/role_scripts/14/standby/ha_backup_job.sh
@@ -72,8 +72,17 @@ echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
 
-echo "wal_keep_size = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
-
+# echo "wal_keep_size = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_size = 1024" >>/tmp/postgresql.conf
+fi
+if [[ "$WAL_LIMIT_POLICY" == "ReplicationSlot" ]]; then
+  CLEAN_HOSTNAME="${HOSTNAME//[^[:alnum:]]/}"
+  echo "primary_slot_name = "$CLEAN_HOSTNAME"" >>/tmp/postgresql.conf
+fi
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 
 # we are not doing any archiving by default but it's better to have this config in our postgresql.conf file in case of customization.
diff --git a/role_scripts/14/standby/run.sh b/role_scripts/14/standby/run.sh
index 2997854..4c4fc99 100755
--- a/role_scripts/14/standby/run.sh
+++ b/role_scripts/14/standby/run.sh
@@ -66,6 +66,30 @@ while true; do
     sleep 2
 done
 
+if [[ "$WAL_LIMIT_POLICY" == "ReplicationSlot" ]]; then
+  CLEAN_HOSTNAME="${HOSTNAME//[^[:alnum:]]/}"
+  while true; do
+      echo "Create replication slot on primary"
+      if [[ "${SSL:-0}" == "ON" ]]; then
+          output=$(psql -h "$PRIMARY_HOST" --username=postgres "sslmode=$SSL_MODE sslrootcert=/tls/certs/client/ca.crt sslcert=/tls/certs/client/client.crt sslkey=/tls/certs/client/client.key" --command="SELECT pg_create_physical_replication_slot('${CLEAN_HOSTNAME}', true);" 2>&1 || true)
+      else
+          output=$(psql -h "$PRIMARY_HOST" --username=postgres --no-password --command="SELECT pg_create_physical_replication_slot('${CLEAN_HOSTNAME}', true);" 2>&1 || true)
+      fi
+      # check if current pod became leader itself
+
+      if [[ $output == *"(1 row)"* || $output == *"already exists"* ]]; then
+        break
+      fi
+
+      if [[ -e "/run_scripts/tmp/pg-failover-trigger" ]]; then
+          echo "Postgres promotion trigger_file found. Running primary run script"
+          /run_scripts/role/run.sh
+      fi
+      sleep 2
+  done
+fi
+
+
 if [[ ! -e "$PGDATA/PG_VERSION" ]]; then
     echo "take base basebackup..."
     mkdir -p "$PGDATA"
@@ -86,8 +110,17 @@ echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
 
-echo "wal_keep_size = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
-
+# echo "wal_keep_size = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_size = 1024" >>/tmp/postgresql.conf
+fi
+if [[ "$WAL_LIMIT_POLICY" == "ReplicationSlot" ]]; then
+  CLEAN_HOSTNAME="${HOSTNAME//[^[:alnum:]]/}"
+  echo "primary_slot_name = "$CLEAN_HOSTNAME"" >>/tmp/postgresql.conf
+fi
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 
 # we are not doing any archiving by default but it's better to have this config in our postgresql.conf file in case of customization.
diff --git a/role_scripts/14/standby/warm_stanby.sh b/role_scripts/14/standby/warm_stanby.sh
index c1c2161..efa33b1 100755
--- a/role_scripts/14/standby/warm_stanby.sh
+++ b/role_scripts/14/standby/warm_stanby.sh
@@ -20,8 +20,17 @@ echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
 
-echo "wal_keep_size = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
-
+# echo "wal_keep_size = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_size = 1024" >>/tmp/postgresql.conf
+fi
+if [[ "$WAL_LIMIT_POLICY" == "ReplicationSlot" ]]; then
+  CLEAN_HOSTNAME="${HOSTNAME//[^[:alnum:]]/}"
+  echo "primary_slot_name="$CLEAN_HOSTNAME"" >>/tmp/recovery.conf
+fi
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 
 # we are not doing any archiving by default but it's better to have this config in our postgresql.conf file in case of customization.
diff --git a/role_scripts/15/primary/start.sh b/role_scripts/15/primary/start.sh
index cf6b37e..2e759ae 100755
--- a/role_scripts/15/primary/start.sh
+++ b/role_scripts/15/primary/start.sh
@@ -20,8 +20,13 @@ echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
 
-echo "wal_keep_size = 1024" >>/tmp/postgresql.conf
-
+# echo "wal_keep_size = 1024" >>/tmp/postgresql.conf
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_size = 1024" >>/tmp/postgresql.conf
+fi
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 
 # we are not doing any archiving by default but it's better to have this config in our postgresql.conf file in case of customization.
diff --git a/role_scripts/15/standby/ha_backup_job.sh b/role_scripts/15/standby/ha_backup_job.sh
index 49c4aaf..3cd9495 100755
--- a/role_scripts/15/standby/ha_backup_job.sh
+++ b/role_scripts/15/standby/ha_backup_job.sh
@@ -74,8 +74,17 @@ echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
 
-echo "wal_keep_size = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
-
+# echo "wal_keep_size = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_size = 1024" >>/tmp/postgresql.conf
+fi
+if [[ "$WAL_LIMIT_POLICY" == "ReplicationSlot" ]]; then
+  CLEAN_HOSTNAME="${HOSTNAME//[^[:alnum:]]/}"
+  echo "primary_slot_name="$CLEAN_HOSTNAME"" >>/tmp/recovery.conf
+fi
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 
 # we are not doing any archiving by default but it's better to have this config in our postgresql.conf file in case of customization.
diff --git a/role_scripts/15/standby/remote-replica.sh b/role_scripts/15/standby/remote-replica.sh
index 6540bbc..39c6523 100755
--- a/role_scripts/15/standby/remote-replica.sh
+++ b/role_scripts/15/standby/remote-replica.sh
@@ -63,8 +63,17 @@ echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
 
-echo "wal_keep_size = 64" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
-
+# echo "wal_keep_size = 64" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_size = 1024" >>/tmp/postgresql.conf
+fi
+if [[ "$WAL_LIMIT_POLICY" == "ReplicationSlot" ]]; then
+  CLEAN_HOSTNAME="${HOSTNAME//[^[:alnum:]]/}"
+  echo "primary_slot_name="$CLEAN_HOSTNAME"" >>/tmp/recovery.conf
+fi
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 
 # we are not doing any archiving by default but it's better to have this config in our postgresql.conf file in case of customization.
diff --git a/role_scripts/15/standby/run.sh b/role_scripts/15/standby/run.sh
index e13a0f9..1a3e7d5 100755
--- a/role_scripts/15/standby/run.sh
+++ b/role_scripts/15/standby/run.sh
@@ -66,6 +66,30 @@ while true; do
     sleep 2
 done
 
+if [[ "$WAL_LIMIT_POLICY" == "ReplicationSlot" ]]; then
+  CLEAN_HOSTNAME="${HOSTNAME//[^[:alnum:]]/}"
+  while true; do
+      echo "Create replication slot on primary"
+      if [[ "${SSL:-0}" == "ON" ]]; then
+          output=$(psql -h "$PRIMARY_HOST" --username=postgres "sslmode=$SSL_MODE sslrootcert=/tls/certs/client/ca.crt sslcert=/tls/certs/client/client.crt sslkey=/tls/certs/client/client.key" --command="SELECT pg_create_physical_replication_slot('${CLEAN_HOSTNAME}', true);" 2>&1 || true)
+      else
+          output=$(psql -h "$PRIMARY_HOST" --username=postgres --no-password --command="SELECT pg_create_physical_replication_slot('${CLEAN_HOSTNAME}', true);" 2>&1 || true)
+      fi
+      # check if current pod became leader itself
+
+      if [[ $output == *"(1 row)"* || $output == *"already exists"* ]]; then
+        break
+      fi
+
+      if [[ -e "/run_scripts/tmp/pg-failover-trigger" ]]; then
+          echo "Postgres promotion trigger_file found. Running primary run script"
+          /run_scripts/role/run.sh
+      fi
+      sleep 2
+  done
+fi
+
+
 if [[ ! -e "$PGDATA/PG_VERSION" ]]; then
     echo "take base basebackup..."
     mkdir -p "$PGDATA"
@@ -86,8 +110,17 @@ echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
 
-echo "wal_keep_size = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
-
+# echo "wal_keep_size = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_size = 1024" >>/tmp/postgresql.conf
+fi
+if [[ "$WAL_LIMIT_POLICY" == "ReplicationSlot" ]]; then
+  CLEAN_HOSTNAME="${HOSTNAME//[^[:alnum:]]/}"
+  echo "primary_slot_name = "$CLEAN_HOSTNAME"" >>/tmp/postgresql.conf
+fi
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 
 # we are not doing any archiving by default but it's better to have this config in our postgresql.conf file in case of customization.
diff --git a/role_scripts/15/standby/warm_stanby.sh b/role_scripts/15/standby/warm_stanby.sh
index 125f253..ed0c6a1 100755
--- a/role_scripts/15/standby/warm_stanby.sh
+++ b/role_scripts/15/standby/warm_stanby.sh
@@ -20,8 +20,17 @@ echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
 
-echo "wal_keep_size = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
-
+# echo "wal_keep_size = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_size = 1024" >>/tmp/postgresql.conf
+fi
+if [[ "$WAL_LIMIT_POLICY" == "ReplicationSlot" ]]; then
+  CLEAN_HOSTNAME="${HOSTNAME//[^[:alnum:]]/}"
+  echo "primary_slot_name = "$CLEAN_HOSTNAME"" >>/tmp/postgresql.conf
+fi
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 
 # we are not doing any archiving by default but it's better to have this config in our postgresql.conf file in case of customization.
diff --git a/role_scripts/16/primary/start.sh b/role_scripts/16/primary/start.sh
index b09af3c..648cc8f 100755
--- a/role_scripts/16/primary/start.sh
+++ b/role_scripts/16/primary/start.sh
@@ -20,10 +20,15 @@ echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
 
-echo "wal_keep_size = 1024" >>/tmp/postgresql.conf
+# echo "wal_keep_size = 1024" >>/tmp/postgresql.conf
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_size = 1024" >>/tmp/postgresql.conf
+fi
 
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
-
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 # we are not doing any archiving by default but it's better to have this config in our postgresql.conf file in case of customization.
 echo "archive_mode = always" >>/tmp/postgresql.conf
 if [[ "${WAL_BACKUP_TYPE:-0}" == "WALG" ]]; then
diff --git a/role_scripts/16/standby/ha_backup_job.sh b/role_scripts/16/standby/ha_backup_job.sh
index dc7cfd1..05abab8 100755
--- a/role_scripts/16/standby/ha_backup_job.sh
+++ b/role_scripts/16/standby/ha_backup_job.sh
@@ -74,8 +74,17 @@ echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
 
-echo "wal_keep_size = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
-
+# echo "wal_keep_size = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_size = 1024" >>/tmp/postgresql.conf
+fi
+if [[ "$WAL_LIMIT_POLICY" == "ReplicationSlot" ]]; then
+  CLEAN_HOSTNAME="${HOSTNAME//[^[:alnum:]]/}"
+  echo "primary_slot_name = "$CLEAN_HOSTNAME"" >>/tmp/postgresql.conf
+fi
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 
 # we are not doing any archiving by default but it's better to have this config in our postgresql.conf file in case of customization.
diff --git a/role_scripts/16/standby/remote-replica.sh b/role_scripts/16/standby/remote-replica.sh
index 7c95aa4..04ad8ec 100755
--- a/role_scripts/16/standby/remote-replica.sh
+++ b/role_scripts/16/standby/remote-replica.sh
@@ -62,8 +62,17 @@ touch /tmp/postgresql.conf
 echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
-
-echo "wal_keep_size = 64" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
+# echo "wal_keep_size = 64" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_size = 1024" >>/tmp/postgresql.conf
+fi
+if [[ "$WAL_LIMIT_POLICY" == "ReplicationSlot" ]]; then
+  CLEAN_HOSTNAME="${HOSTNAME//[^[:alnum:]]/}"
+  echo "primary_slot_name = "$CLEAN_HOSTNAME"" >>/tmp/postgresql.conf
+fi
 
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 
diff --git a/role_scripts/16/standby/run.sh b/role_scripts/16/standby/run.sh
index 29dd11d..cc96d72 100755
--- a/role_scripts/16/standby/run.sh
+++ b/role_scripts/16/standby/run.sh
@@ -66,6 +66,29 @@ while true; do
     sleep 2
 done
 
+if [[ "$WAL_LIMIT_POLICY" == "ReplicationSlot" ]]; then
+  CLEAN_HOSTNAME="${HOSTNAME//[^[:alnum:]]/}"
+  while true; do
+      echo "Create replication slot on primary"
+      if [[ "${SSL:-0}" == "ON" ]]; then
+          output=$(psql -h "$PRIMARY_HOST" --username=postgres "sslmode=$SSL_MODE sslrootcert=/tls/certs/client/ca.crt sslcert=/tls/certs/client/client.crt sslkey=/tls/certs/client/client.key" --command="SELECT pg_create_physical_replication_slot('${CLEAN_HOSTNAME}', true);" 2>&1 || true)
+      else
+          output=$(psql -h "$PRIMARY_HOST" --username=postgres --no-password --command="SELECT pg_create_physical_replication_slot('${CLEAN_HOSTNAME}', true);" 2>&1 || true)
+      fi
+      # check if current pod became leader itself
+
+      if [[ $output == *"(1 row)"* || $output == *"already exists"* ]]; then
+        break
+      fi
+
+      if [[ -e "/run_scripts/tmp/pg-failover-trigger" ]]; then
+          echo "Postgres promotion trigger_file found. Running primary run script"
+          /run_scripts/role/run.sh
+      fi
+      sleep 2
+  done
+fi
+
 if [[ ! -e "$PGDATA/PG_VERSION" ]]; then
     echo "take base basebackup..."
     mkdir -p "$PGDATA"
@@ -80,14 +103,25 @@ else
     /run_scripts/role/warm_stanby.sh
 fi
 
+
+
 # setup postgresql.conf
 touch /tmp/postgresql.conf
 echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
 
-echo "wal_keep_size = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
-
+# echo "wal_keep_size = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_size = 1024" >>/tmp/postgresql.conf
+fi
+if [[ "$WAL_LIMIT_POLICY" == "ReplicationSlot" ]]; then
+  CLEAN_HOSTNAME="${HOSTNAME//[^[:alnum:]]/}"
+  echo "primary_slot_name = "$CLEAN_HOSTNAME"" >>/tmp/postgresql.conf
+fi
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 
 # we are not doing any archiving by default but it's better to have this config in our postgresql.conf file in case of customization.
diff --git a/role_scripts/16/standby/warm_stanby.sh b/role_scripts/16/standby/warm_stanby.sh
index 98c0ab7..538c854 100755
--- a/role_scripts/16/standby/warm_stanby.sh
+++ b/role_scripts/16/standby/warm_stanby.sh
@@ -20,10 +20,19 @@ echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
 
-echo "wal_keep_size = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
+# echo "wal_keep_size = 1024" >>/tmp/postgresql.conf #it was  "wal_keep_segments" in earlier version. changed in version 13
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_size = 1024" >>/tmp/postgresql.conf
+fi
+if [[ "$WAL_LIMIT_POLICY" == "ReplicationSlot" ]]; then
+  CLEAN_HOSTNAME="${HOSTNAME//[^[:alnum:]]/}"
+  echo "primary_slot_name = "$CLEAN_HOSTNAME"" >>/tmp/postgresql.conf
+fi
 
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
-
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 # we are not doing any archiving by default but it's better to have this config in our postgresql.conf file in case of customization.
 echo "archive_mode = always" >>/tmp/postgresql.conf
 echo "archive_command = '/bin/true'" >>/tmp/postgresql.conf
diff --git a/role_scripts/9/primary/start.sh b/role_scripts/9/primary/start.sh
index e3197c0..63ecbec 100755
--- a/role_scripts/9/primary/start.sh
+++ b/role_scripts/9/primary/start.sh
@@ -20,12 +20,17 @@ echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
 
-echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf
-
+# echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_segments = 64" >>/tmp/postgresql.conf
+fi
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 echo "archive_mode = always" >>/tmp/postgresql.conf
 echo "archive_command = '/bin/true'" >>/tmp/postgresql.conf
 echo "shared_preload_libraries = 'pg_stat_statements'" >>/tmp/postgresql.conf
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 
 if [[ "${SSL:-0}" == "ON" ]]; then
     echo "ssl = on" >>/tmp/postgresql.conf
diff --git a/role_scripts/9/standby/ha_backup_job.sh b/role_scripts/9/standby/ha_backup_job.sh
index c8c6530..b94ae61 100755
--- a/role_scripts/9/standby/ha_backup_job.sh
+++ b/role_scripts/9/standby/ha_backup_job.sh
@@ -77,10 +77,17 @@ touch /tmp/postgresql.conf
 echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
-echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf
+#echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_segments = 64" >>/tmp/postgresql.conf
+fi
+
 
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 echo "shared_preload_libraries = 'pg_stat_statements'" >>/tmp/postgresql.conf
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 
 echo "archive_mode = always" >>/tmp/postgresql.conf
 echo "archive_command = '/bin/true'" >>/tmp/postgresql.conf
diff --git a/role_scripts/9/standby/run.sh b/role_scripts/9/standby/run.sh
index effaf7c..74788c5 100755
--- a/role_scripts/9/standby/run.sh
+++ b/role_scripts/9/standby/run.sh
@@ -66,6 +66,29 @@ while true; do
     sleep 2
 done
 
+if [[ "$WAL_LIMIT_POLICY" == "ReplicationSlot" ]]; then
+  CLEAN_HOSTNAME="${HOSTNAME//[^[:alnum:]]/}"
+  while true; do
+      echo "Create replication slot on primary"
+      if [[ "${SSL:-0}" == "ON" ]]; then
+          output=$(psql -h "$PRIMARY_HOST" --username=postgres "sslmode=$SSL_MODE sslrootcert=/tls/certs/client/ca.crt sslcert=/tls/certs/client/client.crt sslkey=/tls/certs/client/client.key" --command="SELECT pg_create_physical_replication_slot('${CLEAN_HOSTNAME}', true);" 2>&1 || true)
+      else
+          output=$(psql -h "$PRIMARY_HOST" --username=postgres --no-password --command="SELECT pg_create_physical_replication_slot('${CLEAN_HOSTNAME}', true);" 2>&1 || true)
+      fi
+      # check if current pod became leader itself
+
+      if [[ $output == *"(1 row)"* || $output == *"already exists"* ]]; then
+        break
+      fi
+
+      if [[ -e "/run_scripts/tmp/pg-failover-trigger" ]]; then
+          echo "Postgres promotion trigger_file found. Running primary run script"
+          /run_scripts/role/run.sh
+      fi
+      sleep 2
+  done
+fi
+
 if [[ ! -e "$PGDATA/PG_VERSION" ]]; then
     echo "take base basebackup..."
     # get basebackup
@@ -91,8 +114,13 @@ touch /tmp/postgresql.conf
 echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
-echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf
-
+# echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_segments = 64" >>/tmp/postgresql.conf
+fi
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 
 echo "archive_mode = always" >>/tmp/postgresql.conf
diff --git a/role_scripts/9/standby/warm_stanby.sh b/role_scripts/9/standby/warm_stanby.sh
index b4387da..73a8305 100755
--- a/role_scripts/9/standby/warm_stanby.sh
+++ b/role_scripts/9/standby/warm_stanby.sh
@@ -22,7 +22,13 @@ touch /tmp/postgresql.conf
 echo "wal_level = replica" >>/tmp/postgresql.conf
 echo "shared_buffers = $SHARED_BUFFERS" >>/tmp/postgresql.conf
 echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
-echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf
+#echo "wal_keep_segments = 1024" >>/tmp/postgresql.conf
+if [ ! -z "${WAL_RETAIN_PARAM:-}" ] && [ ! -z "${WAL_RETAIN_AMOUNT:-}" ]; then
+    echo "${WAL_RETAIN_PARAM}=${WAL_RETAIN_AMOUNT}" >>/tmp/postgresql.conf
+else
+  echo "wal_keep_segments = 64" >>/tmp/postgresql.conf
+fi
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 
 echo "wal_log_hints = on" >>/tmp/postgresql.conf
 echo "shared_preload_libraries = 'pg_stat_statements'" >>/tmp/postgresql.conf
diff --git a/scripts/config_recovery.conf.sh b/scripts/config_recovery.conf.sh
index d6a187f..a4978fc 100755
--- a/scripts/config_recovery.conf.sh
+++ b/scripts/config_recovery.conf.sh
@@ -6,6 +6,10 @@ echo "standby_mode = on" >>/tmp/recovery.conf
 echo "trigger_file = '/run_scripts/tmp/pg-failover-trigger'" >>/tmp/recovery.conf
 echo "recovery_target_timeline = 'latest'" >>/tmp/recovery.conf
 
+if [[ "$WAL_LIMIT_POLICY" == "ReplicationSlot" ]]; then
+  CLEAN_HOSTNAME="${HOSTNAME//[^[:alnum:]]/}"
+  echo "primary_slot_name = "$CLEAN_HOSTNAME"" >>/tmp/recovery.conf
+fi
 # primary_conninfo is used for streaming replication
 if [[ "${SSL:-0}" == "ON" ]]; then
     if [[ "$CLIENT_AUTH_MODE" == "cert" ]]; then
diff --git a/scripts/restore.sh b/scripts/restore.sh
index 77437f6..5af8f5c 100755
--- a/scripts/restore.sh
+++ b/scripts/restore.sh
@@ -33,8 +33,8 @@ if [[ "$PG_MAJOR" == "11" ]]; then
     echo "wal_level = replica" >>/tmp/postgresql.conf
     echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
 
+    # echo "wal_keep_segments = 64" >>/tmp/postgresql.conf
     echo "wal_keep_segments = 64" >>/tmp/postgresql.conf
-
     echo "wal_log_hints = on" >>/tmp/postgresql.conf
 else
     # ****************** Recovery config 12, 13, 14 **************************
@@ -53,7 +53,8 @@ else
     echo "wal_level = replica" >>/tmp/postgresql.conf
     echo "max_wal_senders = 90" >>/tmp/postgresql.conf # default is 10.  value must be less than max_connections minus superuser_reserved_connections. ref: https://www.postgresql.org/docs/11/runtime-config-replication.html#GUC-MAX-WAL-SENDERS
 
-    echo "wal_keep_size = 64" >>/tmp/postgresql.conf
+    # echo "wal_keep_size = 64" >>/tmp/postgresql.conf
+    echo "wal_keep_size = 1024" >>/tmp/postgresql.conf
     echo "hot_standby = on" >>/tmp/postgresql.conf
     echo "wal_log_hints = on" >>/tmp/postgresql.conf
 
@@ -66,7 +67,7 @@ echo "archive_command = '/bin/true'" >>/tmp/postgresql.conf
 
 cat /run_scripts/role/postgresql.conf >>/tmp/postgresql.conf
 mv /tmp/postgresql.conf "$PGDATA/postgresql.conf"
-
+echo "max_replication_slots = 90" >>/tmp/postgresql.conf
 # setup pg_hba.conf for initial start. this one is just for initialization
 touch /tmp/pg_hba.conf
 { echo '#TYPE      DATABASE        USER            ADDRESS                 METHOD'; } >>tmp/pg_hba.conf