Replication slot update

Author: hariramt

articles/postgresql/migrate/migration-service/includes/prerequisites/prerequisites-migration-service-postgresql-online-single-server.md

@@ -19,11 +19,11 @@ Source PostgreSQL version should be `>= 9.5`. If the source PostgreSQL version i
 
 ### Set up Online migration parameters
 
-For Online migration, the replication support should be set to Logical under replication settings of the source PostgreSQL server. In addition, the server parameters `max_wal_senders` and `max_replication_slots` values should be equal to the number of Databases that need to be migrated. They can also be configured in the command line using the following commands:
+For Online migration, the replication support should be set to Logical under replication settings of the source PostgreSQL server. In addition, the server parameters `max_wal_senders` and `max_replication_slots` values should be more than the number of Databases that need to be migrated. The parameters can be set in the Azure portal under **Settings->Server Parameters** or configured in the command line using the following commands:
 
 - ALTER SYSTEM SET wal_level = logical;
-- ALTER SYSTEM SET max_wal_senders = `number of databases to migrate`;
-- ALTER SYSTEM SET max_replication_slots = `number of databases to migrate`;
+- ALTER SYSTEM SET max_wal_senders = `number of databases to migrate` + 1;
+- ALTER SYSTEM SET max_replication_slots = `number of databases to migrate` + 1;
 
 Ensure that there are no **long running transactions**. Long running transactions don't allow creation of replication slots. The creation of a replication slot will succeed if all long running transactions are committed or rolled-back. You'll need to restart the source PostgreSQL server after completing all the Online migration prerequisites.
 
@@ -38,7 +38,9 @@ Ensure that there are no **long running transactions**. Long running transaction
 
 - For detailed instructions on creating a new Azure Database for PostgreSQL, refer to the following link: [Quickstart: Create server](/azure/postgresql/flexible-server/).
 
-- The `pg_replication_origin` parameter on the target should be at least (1 + `number of databases to migrate`) onto the target.
+- The server parameter `max_replication_slots` should be more than the number of Databases that need to be migrated. It can be set in the Azure portal under **Settings->Server Parameters** or configured in the command line using the following command:
+
+- ALTER SYSTEM SET max_replication_slots = `number of databases to migrate` + 1;
 
 ### Network setup
 

articles/postgresql/migrate/migration-service/includes/prerequisites/prerequisites-migration-service-postgresql-online.md

@@ -19,11 +19,11 @@ Source PostgreSQL version should be `>= 9.5`. If the source PostgreSQL version i
 
 ### Set up Online migration parameters
 
-For Online migration, the replication support should be set to Logical under replication settings of the source PostgreSQL server. In addition, the server parameters `max_wal_senders` and `max_replication_slots` values should be equal to the number of Databases that need to be migrated. They can also be configured in the command line using the following commands:
+For Online migration, the replication support should be set to Logical under replication settings of the source PostgreSQL server. In addition, the server parameters `max_wal_senders` and `max_replication_slots` values should be more than the number of Databases that need to be migrated. The parameters can be set in the Azure portal under **Settings->Server Parameters** or configured in the command line using the following commands:
 
 - ALTER SYSTEM SET wal_level = logical;
-- ALTER SYSTEM SET max_wal_senders = `number of databases to migrate`;
-- ALTER SYSTEM SET max_replication_slots = `number of databases to migrate`;
+- ALTER SYSTEM SET max_wal_senders = `number of databases to migrate` + 1;
+- ALTER SYSTEM SET max_replication_slots = `number of databases to migrate` + 1;
 
 Ensure that there are no **long running transactions**. Long running transactions don't allow creation of replication slots. The creation of a replication slot will succeed if all long running transactions are committed or rolled-back. You'll need to restart the source PostgreSQL server after completing all the Online migration prerequisites.
 
@@ -38,7 +38,9 @@ Ensure that there are no **long running transactions**. Long running transaction
 
 - For detailed instructions on creating a new Azure Database for PostgreSQL, refer to the following link: [Quickstart: Create server](/azure/postgresql/flexible-server/).
 
-- The `pg_replication_origin` parameter on the target should be at least (1 + `number of databases to migrate`) onto the target.
+- The server parameter `max_replication_slots` should be more than the number of Databases that need to be migrated. It can be set in the Azure portal under **Settings->Server Parameters** or configured in the command line using the following command:
+
+- ALTER SYSTEM SET max_replication_slots = `number of databases to migrate` + 1;
 
 ### Network setup