Alternative Configurations of PowerExchange and PowerExchange CDC Publisher
Alternative Configurations of PowerExchange and PowerExchange CDC Publisher
When determining how to implement PowerExchange CDC Publisher in your PowerExchange environment, consider the following guidelines:
The PowerExchange CDC Publisher is a client of both the PowerExchange source system and the target messaging system. It can run on any Linux or Windows machine in your environment, including a system that is remote from the data source, target, and PowerExchange Logger for Linux, UNIX, and Windows systems.
The PowerExchange CDC Publisher does not run on platforms other than Linux or Windows.
PowerExchange must be installed on the source system, PowerExchange Logger system, and PowerExchange CDC Publisher system. The CDC Publisher uses the PowerExchange client code from the local PowerExchange installation to communicate with PowerExchange Listener instances on other machines.
The PowerExchange CDC Publisher requires the PowerExchange Logger. The PowerExchange CDC Publisher reads change records from PowerExchange Logger log files. Run a PowerExchange Listener instance on the same machine as the PowerExchange Logger. Then configure the PowerExchange client on the CDC Publisher system to connect to the PowerExchange Listener on that machine to extract change records.
If the PowerExchange Logger is remote from the data source, you must configure remote logging of change data, as described in the
PowerExchange CDC Guide for Linux, UNIX, and Windows
.
The following configurations of PowerExchange and PowerExchange CDC Publisher components are typical:
Configuration 1: All components run on the source system
The data source, PowerExchange Logger for Linux, UNIX, and Windows, PowerExchange Listener, and PowerExchange CDC Publisher run on the same Linux or Windows machine. All of the configuration files reside on this machine, including the PowerExchange dbmover configuration file, PowerExchange Logger pwxccl.cfg configuration file, all CDC Publisher configurations files, and the extraction maps. PowerExchange and the CDC Publisher can share the same dbmover configuration file.
This configuration can be used if the data source is on a Linux or Windows system. This configuration cannot be used if the data source is on an IBM i (i5/OS), UNIX, or z/OS system.
Configuration 2: The PowerExchange Logger runs on the source system and the CDC Publisher runs on a separate system
You can use this configuration if the data source and PowerExchange Logger run on a Linux, UNIX, or Windows system. This configuration is also suitable when you want to add CDC Publisher functionality to an existing PowerExchange environment in which the PowerExchange Logger for Linux, UNIX, and Windows logs change data locally on the source system.
Because the PowerExchange Logger extracts change data from the data source locally, you do not need to configure remote logging. The PowerExchange client on the CDC Publisher system connects to the PowerExchange Listener on the PowerExchange Logger system to retrieve the change data. The source system and CDC Publisher systems must have separate dbmover configuration files. The dbmover configuration file on the CDC Publisher system includes a NODE statement that points to the source host.
This configuration can be used if the data source is on a Linux, UNIX, or Windows system. This configuration cannot be used if the data source is on an IBM i or z/OS system.
The following image shows this configuration:
In this image,
change data source
can be Db2 LUW transaction logs, Oracle active and archived redo logs, or a Microsoft SQL Server distribution database.
Configuration 3: The PowerExchange Logger and CDC Publisher run on a system that is remote from the source
The PowerExchange Logger for Linux, UNIX, and Windows and PowerExchange CDC Publisher components run on the same Linux or Windows system. Because the PowerExchange Logger is remote from the data source, you must configure PowerExchange for remote logging, as described in the
PowerExchange CDC Guide for Linux, UNIX, and Windows
. The source system and the Logger and CDC Publisher system must have separate dbmover configuration files. The dbmover configuration file on the Logger and CDC Publisher system includes a NODE statement that points to the source host.
This configuration accommodates data sources on IBM i, UNIX, or z/OS as well as data sources on Linux and Windows.
The following image shows this configuration:
In this image,
change data source
is broadly defined as including PowerExchange Logger for z/OS log files or PowerExchange Condense files on z/OS, journal receivers or PowerExchange Condense files on IBM i (i5/OS), Db2 LUW transaction logs, Oracle redo logs, or a Microsoft SQL Server database.
Configuration 4: The data source, PowerExchange Logger, and PowerExchange CDC Publisher run on three separate machines
You can use this configuration to process change data from a source on a platform such as i5/OS or z/OS on which the PowerExchange Logger for Linux, UNIX, and Windows and PowerExchange CDC Publisher cannot run. This configuration is also suitable when you want to add CDC Publisher functionality to an existing PowerExchange environment that uses remote logging of change data to PowerExchange Logger for Linux, UNIX, and Windows log files.
On each system, define a PowerExchange dbmover configuration file. The dbmover configuration file on the CDC Publisher system includes a NODE statement that is used to connect to the source system to read extraction maps and another NODE statement that is used to connect to the Logger system to retrieve change data from the Logger log files. The CDC Publisher system also contains the PowerExchange CDC Publisher configuration files and the Kafka producer.properties file that the CDC Publisher uses to connect to Kafka.
The following image shows this configuration, including the locations of the extraction maps and the PowerExchange, CDC Publisher, and Kafka configuration files:
In this image,
change data source
is broadly defined as including PowerExchange Logger for z/OS log files or PowerExchange Condense files on z/OS, journal receivers or PowerExchange Condense files on IBM i (i5/OS), Db2 LUW transaction logs, Oracle redo logs, or a Microsoft SQL Server database.
The general process flow is:
PowerExchange captures change data from the local data source based on capture registrations.
PowerExchange remotely logs the change data to the PowerExchange Logger log files on another system. The PowerExchange Logger logs changes from successful units of work (UOWs) in commit order.
The PowerExchange client on the PowerExchange CDC Publisher system retrieves change data from the PowerExchange Logger log files, maintaining the commit order.
The CDC Publisher extracts the change data for source objects of interest, formats the data into messages, and connects to the target messaging system to transmit the messages.
