Enabling event sequencing: JMS exports
To enable event sequencing for JMS export bindings in IBM BPM, configure properties of the binding. Also, the export must process and deliver messages in the same order that it receives those messages.
Event sequencing for JMS export bindings is supported in a clustered environment only when the destinations are not partitioned. For event sequencing to function in a ND environment with clusters, there can be only one active messaging engine per cluster. For event sequencing in a ND environment with servers that are not in a cluster, each server can have an active messaging engine.
Event sequencing requires events to acquire a lock before being dispatched to the target component for processing. When processing is complete, the event releases the lock. If an event cannot acquire a lock, processing of the invocation is suspended. If the event subsequently acquires a lock, it will be dispatched.
You declare that event sequencing is required on a particular method for a particular component by adding an event sequencing qualifier to the method in the component definition.
- The keySpecification attribute defines the key that will be used to identify the events that need to be sequenced.
- The parameter attribute specifies the parameter from which the key attributes will be extracted.
- The name attribute is the name of the parameter.
- The xpath attribute is applied to the parameter to extract a value that will be part of the key.
Specify a parameter element for each parameter that is going to contribute to the key.
The esadmin command line utility can be used to list locks and delete locks, both active and queued.
You enable event sequencing for a JMS export from Integration Designer.
Procedure
- In Integration Designer, click the Properties tab for the export.
- From the Message configuration section, select the Event sequence required check box.
Results
Event sequencing is enabled for your binding.Removing the exception destination means that any failure will stop all incoming messages.
Related concepts:
JMS bindings