Specifying the workload preference

CDC Replication provides the ability to specify whether your source or target should try to minimize CPU load in order to improve performance.

About this task

Encoding conversion is one process that respects this preference. There are a number of factors that influence where the encoding conversion will take place and because of these, this preference is not a guarantee. Factors influencing where the encoding conversion takes place include the encoding conversion capabilities of the source and target, and the number of table mappings of a single source column to target columns.

The workload preference in CDC Replication defaults to having the workload processed on the target. Therefore, by default, encoding conversion, which attempts to respect the workload preference, will occur on the target. You also have an option to specify the source. This is a change in behavior from previous releases of CDC Replication which always perform encoding conversion on the source with no option to specify the target. Subscriptions that are upgraded from CDC Replication version 6.3 and earlier will perform encoding conversion on the source by default, although you now have the option of specifying the target. Encoding conversion is a CPU intensive activity and you should take this into consideration when deciding where encoding conversion will take place.

Procedure

  1. Click Configuration > Subscriptions.
  2. Right-click the subscription that contains table mappings with encoding conversion work and select Properties.
  3. Click Advanced Settings.
  4. Select one of the following options from the Select the datastore to handle transferable work drop down box:
    Target
    CDC Replication will attempt to perform the encoding conversion workload on the server where your target datastore is installed. This is the default setting.
    Source
    CDC Replication will attempt to perform the encoding conversion workload on the server where your source datastore is installed. This is the default setting for subscriptions that have been upgraded from CDC Replication version 6.3 and earlier.
    Note: If your target datastore is a CDC Replication Engine for InfoSphere® DataStage®, encoding conversion workload will always take place on the server where your target datastore is installed.
  5. Click OK and click OK again.
  6. A progress bar is displayed while Management Console updates the subscription properties.