Bidirectional Non-ASE to Non-ASE Replication

Replication occurs both to and from each database in a bidirectional non-ASE to non-ASE replication scenario.

Each non-ASE database must have both a Replication Agent and an ECDA database gateway.

Replication System Components

The following components are required for a bidirectional non-ASE primary to non-ASE replicate configuration:

Non-ASE primary data server. For example, DB2 UDB on UNIX, Windows, and Linux.
Replication Agent designed for the primary data server. For example, Replication Agent for Oracle, Microsoft SQL Server, and DB2 UDB.
ExpressConnect (for Oracle or HANA DB) to replicate to Oracle or HANA DB, or a relevant ECDA database gateway designed for the replicate data server, such as the ECDA Option for ODBC (for DB2 UDB).
Replication Server.
ExpressConnect (for Oracle or HANA DB) to replicate to Oracle or HANA DB, or a relevant ECDA database gateway designed for the replicate data server, such as the ECDAOption for ODBC for Microsoft SQL Server.
Replication Agent designed for the “replicate” data server acting as a primary database. For example, Replication Agent for Linux, Microsoft Windows, and UNIX.
Non-ASE replicate data server. For example, Microsoft SQL Server.

Replication System Issues

From a technical standpoint, you can set up a bidirectional replication scenario using only two Replication Server database connections (one “primary-and-replicate” connection for each database).

Note: In the following description of bidirectional replication issues, the two databases are referred to as Database #1 and Database #2, because both databases take on both “primary” and “replicate” roles in the replication system.

Consider the following issues in a bidirectional non-ASE primary to non-ASE replicate configuration:

To use direct-load materialization, you must have two connections for each database: one for incoming data and one for outgoing data. You must create the connection for incoming data—which is used by Replication Agent—using the appropriate connection profile (rs_rs_to_<replicate>_ra, where <replicate> is oracle, mssql, udb, or hanadb). Use a connection profile supporting normal replication to create the connection for outgoing data.
The Replication Server primary database connection for Database #1 must include a valid user ID and password for the primary database. This user ID must be the same user ID specified in the Replication Server replicate database connection for Database #2 (the maintenance user). This user ID must have authority to apply transaction operations to replicate tables in Database #1.
The Replication Agent for Database #1 must be configured to bypass maintenance user transactions to prevent a transaction from returning from the replicate tables in Database #2. See the appropriate Replication Agent documentation for details on configuring the Replication Agent to bypass maintenance user transactions.
The Replication Server primary database connection for Database #2 must include a valid user ID and password for the primary database. This user ID must be the same user ID specified in the Replication Server replicate database connection for Database #1 (the maintenance user). This user ID must have authority to apply transaction operations to replicate tables in Database #2.
The Replication Agent for Database #2 must be configured to bypass maintenance user transactions to prevent a transaction from returning from the replicate tables in Database #1. Refer to the appropriate Replication Agent documentation for details on configuring the Replication Agent to bypass maintenance user transactions.
The Replication Server replicate database connections to Database #1 and Database #2 must be created using the correct profile for the replicate database. The connection profile specifies the correct function-string classes and error classes for the replicate database, and additionally may contain class-level translation definitions and replicate database object creation, to support replication.