Menu
AWS Database Migration Service
User Guide (Version API Version 2016-01-01)

Control Table Task Settings

Control tables provide information about the AWS DMS task, as well as useful statistics that you can use to plan and manage both the current migration task and future tasks. You can apply these task settings in a JSON file or using the Advanced Settings link on the Create task page in the AWS DMS console. In addition to the Apply Exceptions (dmslogs.awsdms_apply_exceptions) table, which is always created, you can choose to create additional tables including the following:

  • Replication Status (dmslogs.awsdms_status) – This table provides details about the current task including task status, amount of memory consumed by the task, number of changes not yet applied to the target, and the position in the source database from which AWS DMS is currently reading. It also indicates if the task is a full load or change data capture (CDC).

  • Suspended Tables (dmslogs.awsdms_suspended_tables) – This table provides a list of suspended tables as well as the reason they were suspended.

  • Replication History (dmslogs.awsdms_history) – This table provides information about the replication history including the number and volume of records processed during the task, latency at the end of a CDC task, and other statistics.

The Apply Exceptions (dmslogs.awsdms_apply_exceptions) table contains the following parameters:

Column Type Description

TASK_NAME

nvchar

The name of the AWS DMS task.

TABLE_OWNER

nvchar

The table owner.

TABLE_NAME

nvchar

The table name.

ERROR_TIME

timestamp

The time the exception (error) occurred.

STATEMENT

nvchar

The statement that was being run when the error occurred.

ERROR

nvchar

The error name and description.

The Replication History (dmslogs.awsdms_history) table contains the following parameters:

Column Type Description

SERVER_NAME

nvchar

The name of the machine where the replication task is running.

TASK_NAME

nvchar

The name of the AWS DMS task.

TIMESLOT_TYPE

varchar

One of the following values:

  • FULL LOAD

  • CHANGE PROCESSING (CDC)

If the task is running both full load and CDC, two history records are written to the time slot.

TIMESLOT

timestamp

The ending timestamp of the time slot.

TIMESLOT_DURATION

int

The duration of the time slot.

TIMESLOT_LATENCY

int

The target latency at the end of the time slot. This value is only applicable to CDC time slots.

RECORDS

int

The number of records processed during the time slot.

TIMESLOT_VOLUME

int

The volume of data processed in MB.

The Replication Status (dmslogs.awsdms_status) table contains the current status of the task and the target database. It has the following settings:

Column Type Description

SERVER_NAME

nvchar

The name of the machine where the replication task is running.

TASK_NAME

nvchar

The name of the AWS DMS task.

TASK_STATUS

varchar

One of the following values:

  • FULL LOAD

  • CHANGE PROCESSING (CDC)

Task status is set to FULL LOAD as long as there is at least one table in full load. After all tables have been loaded, the task status changes to CHANGE PROCESSING if CDC is enabled.

STATUS_TIME

timestamp

The timestamp of the task status.

PENDING_CHANGES

int

The number of change records that were not applied to the target.

DISK_SWAP_SIZE

int

The amount of disk space used by old or offloaded transactions.

TASK_MEMORY

int

Current memory used, in MB.

SOURCE_CURRENT

_POSITION

varchar

The position in the source database that AWS DMS is currently reading from.

SOURCE_CURRENT

_TIMESTAMP

timestamp

The timestamp in the source database that AWS DMS is currently reading from.

SOURCE_TAIL

_POSITION

varchar

The position of the oldest start transaction that is not committed. This value is the newest position that you can revert to without losing any changes.

SOURCE_TAIL

_TIMESTAMP

timestamp

The timestamp of the oldest start transaction that is not committed. This value is the newest timestamp that you can revert to without losing any changes..

SOURCE_TIMESTAMP

_APPLIED

timestamp

The timestamp of the last transaction commit. In a bulk apply process, this value is the timestamp for the commit of the last transaction in the batch.

Additional control table settings include the following:

  • ControlSchema – Use this option to indicate the database schema name for the AWS DMS target Control Tables. If you do not enter any information in this field, then the tables are copied to the default location in the database.

  • HistoryTimeslotInMinutes – Use this option to indicate the length of each time slot in the Replication History table. The default is 5 minutes.