Full-load task settings - AWS Database Migration Service

Full-load task settings

Full-load settings include the following. For information about how to use a task configuration file to set task settings, see Task settings example.

  • To indicate how to handle loading the target at full-load startup, specify one of the following values for the TargetTablePrepMode option:

    • DO_NOTHING – Data and metadata of the existing target table aren't affected.

    • DROP_AND_CREATE – The existing table is dropped and a new table is created in its place.

    • TRUNCATE_BEFORE_LOAD – Data is truncated without affecting the table metadata.

  • To delay primary key or unique index creation until after a full load completes, set the CreatePkAfterFullLoad option to true.

  • For full-load and CDC-enabled tasks, you can set the following options for Stop task after full load completes:

    • StopTaskCachedChangesApplied – Set this option to true to stop a task after a full load completes and cached changes are applied.

    • StopTaskCachedChangesNotApplied – Set this option to true to stop a task before cached changes are applied.

  • To indicate the maximum number of tables to load in parallel, set the MaxFullLoadSubTasks option. The default is 8; the maximum value is 49.

  • Set the ParallelLoadThreads option to indicate how many concurrent threads DMS will employ during a full-load process to push data records to a target endpoint. Zero is the default value (0).

    Important

    MaxFullLoadSubTasks controls the number of tables or table segments to load in parallel. ParallelLoadThreads controls the number of threads that are used by a migration task to execute the loads in parallel. These settings are multiplicative. As such, the total number of threads that are used during a full load task is approximately the result of the value of ParallelLoadThreads multiplied by the value of MaxFullLoadSubTasks (ParallelLoadThreads * MaxFullLoadSubtasks).

    If you create tasks with a high number of Full Load sub tasks and a high number of parallel load threads, your task can consume too much memory and fail.

  • You can set the number of seconds that AWS DMS waits for transactions to close before beginning a full-load operation. To do so, if transactions are open when the task starts set the TransactionConsistencyTimeout option. The default value is 600 (10 minutes). AWS DMS begins the full load after the timeout value is reached, even if there are open transactions. A full-load-only task doesn't wait for 10 minutes but instead starts immediately.

  • To indicate the maximum number of records that can be transferred together, set the CommitRate option. The default value is 10000, and the maximum value is 50000.