Replication Definition Overview and Maintenance

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# Replication Definition Overview and Maintenance

To use Event Replicator for Adabas and customize its processing, you must supply various replication definitions. These definitions can be:

- Specified as initialization parameters, which are read from the DDKARTE statements of the Event Replicator Server startup job. For more information, read Event Replicator Initialization Parameters.

- Read from the Replicator system file at Event Replicator Server startup. The definitions are maintained in the Replicator system file using the Adabas Event Replicator Subsystem. For more information, read Maintaining Replication Definitions Using the Adabas Event Replicator Subsystem.

  Note
  If you use a Replicator system file to store your replication definitions, you can also use the RPLREFRESH command to refresh resource definitions in your Event Replicator Server configuration while the Event Replicator Server is still running. For more information, read RPLREFRESH Command.

You can elect to use one or both methods, depending on what works best for you. The method used is controlled by ADARUN parameter RPLPARMS.

This document covers the following replication definition topics:

- Definition Descriptions

- Definition Specification Sequence

## Definition Descriptions

Once the Event Replicator for Adabas in installed, its replication processing is driven by definitions you specify. These definitions are described in the following table in order of importance to replication (required definitions are listed first).

Note
You can run Event Replicator for Adabas in verify (test) mode, by turning on verification in the VERIFYMODE replication definition. This is useful if you want to test the definitions you have specified before you start using Event Replicator for Adabas in production mode. For more information, read Running in Verify Mode.

Definition Type | Defines | How many definitions are required?
--- | --- | ---
destination | The destination of the replicated data. Destination definitions can be created for Adabas, File, IBM EntireX, WebSphere MQ, and Null destinations. To maintain destination definitions using DDKARTE statements of the Event Replicator Server startup job, read Destination Parameter. To maintain destination definitions using the Adabas Event Replicator Subsystem, read Maintaining Destination Definitions. | Required. At least one destination definition is required for data replication to occur. Create one definition for every Event Replicator for Adabas destination you intend to use.
subscription | A set of specifications to be applied to the replication of the data. These include (but are not limited to): the identification of the Adabas files that should be replicated and how they should be replicated (SFILE definitions that should be processed as part of the subscription) architecture key, output alpha and wide-character keys that should be used the name of the resend buffer definition that should be used for replication, if any various settings relating to the availability of the subscription in specific circumstances Subscription definitions identify SFILE definitions and resend buffer definitions that should be used. At least one SFILE definition is required. To maintain subscription definitions using DDKARTE statements of the Event Replicator Server startup job, read SUBSCRIPTION Parameter. To maintain subscription definitions using the Adabas Event Replicator Subsystem, read Maintaining Subscription Definitions. | Required. At least one subscription definition is required for data replication to occur.
SFILE | An Adabas file to be replicated and the replication processing that should occur for that file. SFILE definitions are sometimes referred to as subscription file definitions and are referenced by subscription definitions. An SFILE definition identifies (among other things): the Adabas database ID and file number that should be replicated the transaction filter definitions that should be used to filter the data in the Adabas file during replication (if any) the subscription user exit that should be processed during replication (if any) whether insert, delete, and update transactions should be replicated the file’s alpha character encoding, if any the GFB definitions that should be used for replication, if any, or the specific format buffer definitions that should be used instead. To maintain SFILE definitions using DDKARTE statements of the Event Replicator Server startup job, read SUBSCRIPTION Parameter. To maintain SFILE definitions using the Adabas Event Replicator Subsystem, read Maintaining SFILE Definitions. | Required. At least one SFILE definition is required for data replication to occur.
initial-state | An initial-state request for data from the target application. Initial-state definitions identify the subscription, destination, and specific Adabas files to use in an Event Replicator for Adabas initial-state run. To maintain initial-state definitions using DDKARTE statements of the Event Replicator Server startup job, read INITIALSTATE Parameter. To maintain initial-state definitions using the Adabas Event Replicator Subsystem, read Maintaining Initial-State Definitions. | Not required. If you want initial-state data produced in an Event Replicator for Adabas run, only one initial-state definition is required. Otherwise, no initial-state data definition is required.
IQUEUE | The input queue on which Event Replicator for Adabas should listen for requests from IBM EntireX and WebSphere MQ targets. To maintain IQUEUE definitions using DDKARTE statements of the Event Replicator Server startup job, read IQUEUE Parameter. To maintain IQUEUE definitions using the Adabas Event Replicator Subsystem, read Maintaining Input Queue (IQUEUE) Definitions. | Not required. At least one IQUEUE definition is required for every EntireX Communicator or WebSphere MQ target you intend to use. If IBM EntireX or WebSphere MQ are not used, no IQUEUE definition is required.
GFB | A global format buffer (GFB) definition stored separately for use in SFILE definitions. You can specify GFBs manually or generate them using Predict file definitions. When you generate them, a field table is also generated. While a format buffer specification is required in a subscription's SFILE definition, a stored GFB definition does not need to be used. The SFILE definition could simply include the format buffer specifications it needs. To maintain GFB definitions using DDKARTE statements of the Event Replicator Server startup job, read GFORMAT Parameter. To maintain GFB definitions using the Adabas Event Replicator Subsystem, read Maintaining GFB Definitions. | Not required. No GFB definition is required. If a global format buffer is needed, at least one GFB definition is required.
resend buffer | A resend buffer that can be used by any subscription to expedite the retransmission of a transaction. To maintain resend buffer definitions using DDKARTE statements of the Event Replicator Server startup job, read RESENDBUFFER Parameter. To maintain resend buffer definitions using the Adabas Event Replicator Subsystem, read Maintaining Resend Buffer Definitions. | Not required. No resend buffer definition is required. If you elect to retransmit a transaction, at least one resend buffer definition is required.
transaction filter | A filter definition that can be used to filter the records used for replication based on the values of fields in those records. To maintain transaction filter definitions using DDKARTE statements of the Event Replicator Server startup job, read FILTER Parameter. To maintain transaction filter definitions using the Adabas Event Replicator Subsystem, read Maintaining Transaction Filter Definitions. | Not required. No transaction filter definition is required. If you want to use a transaction filter to filter records used in replication, at least one transaction filter definition is required.

## Definition Specification Sequence

The applicable definitions and the sequence in which they should be set up varies, depending on the destination. Five destinations are supported in the Event Replicator for Adabas: Adabas, IBM EntireX, IBM WebSphere MQ, File, and Null. The following table describes each of these destination types and lists the definitions that apply to the destination in the order in which they should be defined.

Destination Type | Description | Definition List and Order of Creation
--- | --- | ---
Adabas | Data is replicated to one or more Adabas files. | destination definitions, as necessary (referenced by subscription definitions) global format buffer definitions, if needed (can be referenced by the SFILE definitions) subscription definition, including at least one SFILE definition one or more SFILE definitions (included in the subscription definition) initial-state definition
IBM EntireX | Replicated data is written to an output queue via IBM EntireX. | destination definitions, as necessary (referenced by subscription definitions) IQUEUE definition global format buffer definitions, if needed (can be referenced by the SFILE definitions) subscription definition, including at least one SFILE definition one or more SFILE definitions (included in the subscription definition) initial-state definition
File | Replicated data is written to the CLOG, using TLOG URBLTDOD records. | destination definitions, as necessary (referenced by subscription definitions) global format buffer definitions, if needed (can be referenced by the SFILE definitions) subscription definition, including at least one SFILE definition one or more SFILE definitions (included in the subscription definition) initial-state definition
WebSphere MQ | Replicated data is written to an output queue via IBM WebSphere MQ. | destination definitions, as necessary (referenced by subscription definitions) IQUEUE definition global format buffer definitions, if needed (can be referenced by the SFILE definitions) subscription definition, including at least one SFILE definition one or more SFILE definitions (included in the subscription definition) initial-state definition
Null | Data replication is tested without actually sending the data to a destination. | destination definitions, as necessary (referenced by subscription definitions) global format buffer definitions, if needed (can be referenced by the SFILE definitions) subscription definition, including at least one SFILE definition one or more SFILE definitions (included in the subscription definition) initial-state definition

### On this page

- Definition Descriptions
- Definition Specification Sequence