tencent cloud

Check Details

If you select incremental migration as the migration type, you need to check the following conditions; otherwise, the verification will fail.

• The major version of the source and target databases need to be below PostgreSQL 10.x.
• wal_level in the source database must be set to logical.
• The max_replication_slots and max_wal_senders values in the target database must be greater than the total number of databases to be migrated.
• The max_worker_processes value in the target database must be greater than the max_logical_replication_workers value.
• The tables to be migrated should not include unlogged tables; otherwise, they cannot be migrated.

Fix

If the version does not meet the requirements, you need to upgrade it. You can change the values of the wal_level, max_replication_slots, max_worker_processes, and max_wal_senders as follows:

1. Log in to the source database.

   Note：

   • If the source database is self-built, you need to log in to the server where the database runs and enter the main data directory of the database, which is usually $PGDATA.
   • If the source database is in another cloud, modify the parameters as requested by the corresponding cloud vendor.
   • If you need to modify the parameters in the target database, submit a ticket for assistance.

2. Open the postgresql.conf file and modify wal_level.

   wal_level = logical
   

3. After the modification is completed, restart the database.
4. Log in to the database and run the following command to check whether the parameters are correctly set:

   postgres=> select name,setting from pg_settings where name='wal_level';
   name    | setting 
   -----------+---------
   wal_level | logical
   (1 row)
   postgres=> select name,setting from pg_settings where name='max_replication_slots';
        name          | setting 
   -----------------------+---------
   max_replication_slots | 10
   (1 row)
   postgres=> select name,setting from pg_settings where name='max_wal_senders';
     name       | setting 
   -----------------+---------
   max_wal_senders | 10
   (1 row)
   

5. Run the verification task again.