Adabas CDC Connector rules and guidelines

Review the Adabas CDC Connector rules and guidelines before you begin creating connections, mappings, and mapping tasks.

•Adabas CDC connections are for sources only. Do not specify a Adabas CDC connection for a target.

•Adabas CDC Connector connects to a PowerExchange Listener on the PowerExchange source system by using the Listener Location property in the Adabas CDC connection definition. On the connector system, you do not need to create a local copy of the dbmover.cfg configuration file that contains a NODE statement pointing to the PowerExchange Listener.

•If you upgrade your system to a later PowerExchange version, you must stop the Secure Agent that connects to the older PowerExchange Listener before you try to connect to the upgraded PowerExchange Listener. After you edit the connection properties to specify the upgraded PowerExchange Listener, restart the Secure Agent before you try to establish the connection again. For more information, see Upgrading to a new version of PowerExchange.

•The PowerExchange Listener can compress or encrypt the change data that it sends to the PWX CDC Reader component of Adabas CDC Connector depending on how you set the Compression and Encryption properties for the connection.

•Adabas CDC Connector supports PowerExchange Logger group definition files. A group definition file creates a separate set of PowerExchange Logger log files for each defined group of registered Adabas source tables. When a mapping task runs, the PWX CDC Reader reads only the subset of log files for the group that contains the source table.

•If you include multiple Adabas source tables in a mapping, the PWX CDC Reader automatically uses group source processing to read change records for all of the tables in a single pass.

•The PWX CDC Metadata Adapter retrieves information for registered Adabas source tables from the PowerExchange extraction-map metadata file, CAMAPS. The Adapter retrieves information only from PowerExchange-generated extraction maps that have names beginning with "d." The extraction maps provide information, such as the incoming fields, to use when you create a mapping. The Adapter does not retrieve information from user-defined extraction maps that have names beginning with "u" for user-defined.

• The PowerExchange change data extraction modes, as defined in the PowerExchange CDC Guide for z/OS, do not pertain to the Adabas CDC Connector. The PWX CDC Reader component of Adabas CDC Connector extracts change records until it reaches the end-of-log in the PowerExchange Logger log files and then stops. However, the PowerExchange configuration that the PWX CDC Reader requires is similar to the configuration for continuous extraction mode in the following ways:

- A CAPX CAPI_CONNECTION statement must exist in the PowerExchange DBMOVER configuration file.
- The capture registrations for Adabas source tables must specify Part for the Condense option.

• The maximum network buffer size that the PowerExchange Listener can use for sending data is 8 MB. If you have a mapping with an extremely large Adabas source table, this maximum buffer size might be exceeded. In this case, the mapping task fails with the following error:

PWXPC_10034 [date time] [ERROR] CDCDispatcher cannot fetch changed data from the PowerExchange Listener. Error code: [271]

•If you change the source object in a mapping that has been used for CDC processing, create a new mapping task for the mapping. If you need to retain the mapping task that is currently associated with the mapping, increment the revision number in the CDC Runtime properties for the mapping task.

•PowerExchange imports Long Alpha (LA) fields with a default length of 1,024 bytes. You can override this default length by editing the data map in the PowerExchange Navigator. For more information, see the PowerExchange CDC Guide for z/OS.

•The PowerExchange PCAT utility, DTLCCADW, can read archived Adabas PLOG records from tape data sets, including data sets that have a block size greater than 32,760. The Adabas CDC Connector can then capture change data from those PLOG records.

•PowerExchange can capture change data from Adabas spanned records up to their maximum size. The Adabas maximum size depends on the device type.

Tip: If you capture change data from Adabas spanned records larger than 32 KB, PowerExchange might allocate a large number of spill files during the extraction of change data, depending on the MEMCACHE parameter setting in the UOWC CAPI_CONNECTION statement of the DBMOVER member. This situation can slow down subsequent extraction processing. To reduce the number of spill files, increase the MEMCACHE parameter value in the UOWC CAPI_CONNECTION statement