Copyright © TIBCO Software Inc. All Rights Reserved
Copyright © TIBCO Software Inc. All Rights Reserved


Chapter 8 Database Failure and Failover : TIBCO iProcess Engine Configuration Requirements

TIBCO iProcess Engine Configuration Requirements
The following sections describe what you need to do to provide failure/failover support on the TIBCO iProcess Engine.
Oracle (UNIX or Linux)
To provide failure/failover support on the Oracle (UNIX/Linux) variant of the TIBCO iProcess Engine, you MUST configure the use of Oracle’s Transparent Application Failover (TAF) feature. Oracle TAF enables an application user (such as the iProcess Engine) to automatically reconnect to a database if the connection fails.
The TIBCO iProcess Engine Process Sentinels are event driven. On the Oracle (UNIX/Linux) variant of the TIBCO iProcess Engine, the event system is provided using Oracle AQ’s publish/subscribe mechanism. This means that if the database connection fails, the Process Sentinels cannot receive events, and so appear to hang. To avoid this problem you need to configure TAF so that the connection can be restored. Once the connection is restored, all connections are recovered and normal operation is resumed.
If you are running parallel servers, using TAF allows iProcess to switch to an alternative instance if the instance that it is currently using fails.
If you are not running parallel servers, using TAF still means that although iProcess will not function while the database is down, it can recover immediately and automatically when the database is recovered.
To enable the use of TAF with the iProcess Engine, you need to configure TAF support for the service name that you intend to use to connect to the Oracle database. See the TIBCO iProcess Engine (Oracle) for UNIX or Linux Installation Guide for more information about how to do this.
TAF involves manual configuration of a net service name that includes the FAILOVER_MODE parameter included in the CONNECT_DATA section of the connect descriptor. For more information about TAF, and how to set up and configure it, please see your Oracle documentation.
Oracle (Windows), SQL Server and DB2 (UNIX or Linux)
Database failure support is provided automatically. You do not need to configure the TIBCO iProcess Engine in any way - it recovers immediately and automatically when the database connection is restored.
Database failover support is provided automatically provided that you have configured your database system to provide failover capability. For example, by implementing failover clustering in SQL Server, or by using DB2’s high availability disaster recovery (HADR) database replication feature. (Failover capability can be provided in many ways, depending on the hardware, operating system and database systems you are using. Please see your SQL Server or DB2 documentation for more information about how to do this.) You do not need to configure the TIBCO iProcess Engine in any way - it recovers immediately and automatically when the failover completes and the database connection is restored.
Event handling is provided by the iProcess Events COM+ application on Windows variants, and by iProcess event/notification daemons on the UNIX DB2 variant. Consequently, the event system has no dependency on the database as it does in the UNIX/Linux Oracle variant.

Copyright © TIBCO Software Inc. All Rights Reserved
Copyright © TIBCO Software Inc. All Rights Reserved