About Oracle Human Workflow

16-6 Oracle Fusion Middleware Performance and Tuning Guide These techniques also reduce the database and service logic performance impacts at the server and can improve server performance. In addition, a few other configuration changes can be made to improve server performance: ■ Archive Completed Instances Periodically ■ Select the Appropriate Workflow Callback Functionality ■ Minimize Performance Impacts from Notification ■ Deploy Clustered Nodes

16.3.1 Archive Completed Instances Periodically

The database scalability of a system is largely dependent on the amount of data in the system. Since business processes and workflows are temporal in nature, once they are processed, they are not queried frequently. Having numerous completed instances in the system can slow the system. Consider using an archival scheme to periodically move completed instances to another system that can be used to query historical data. Archival should be done carefully to avoid orphan task instances.

16.3.2 Select the Appropriate Workflow Callback Functionality

The workflow callback functionality can be used to query or update external systems after any significant workflow event, such as assignment or completion of task. While this functionality is very useful, it has to be implemented correctly to avoid impacting performance. When performance is critical, ensure that there are sufficient resources to update the external system after the task is completed instead of after every workflow event. For example, instead of using a callback, the service can be invoked once after the completion of the task. If a callback cannot be avoided, then consider using a Java callback instead of a BPEL callback. Java callbacks do not have the performance impact associated with a BPEL callback since the callback method is executed in the same thread. In contrast, a BPEL callback may impact performance when sending a message to the BPEL engine, which in turn must be correlated so that it is delivered to the correct process instance. The workflow service has to be called by the BPEL engine after the invocation of the service.

16.3.3 Minimize Performance Impacts from Notification

Notifications are useful for alerting users that they have a task to execute. In environments where most approvals happen through email, actionable notifications are especially useful. This also implies that there is not much load in terms of worklist usage. However if most users interact through the Worklist, and notifications serve a secondary purpose, then notifications should be used judiciously. Consider minimizing the notification to just alert a user when a task is assigned instead of sending out notifications for each workflow event. Also, if the task content is also mailed in the notification there may be an impact to performance. To minimize the impact, consider making the notifications secure in which case only a link to the task is sent in the notification and not the task content itself.

16.3.4 Deploy Clustered Nodes

All workflow instances and state information are stored in the dehydration database. Workflow services are stateless which means they can be used concurrently on a cluster of nodes. When performance is critical and a highly scalable system is needed, a clustered environment can be used for supporting workflow. For more information