"When you create a JCD that implements an existing web service (ie a JCD that is started by a connector), eDesigner will create a message driven bean that is triggered by the connector and a stateless session bean that will be called from the message driven bean. This stateless session bean will call your JCD web service method, the receive or the start method.
Because your JCD is hosted in a stateless session bean it will receive all the benefits of the J2EE thread and instance management. If there are multiple JMS messages to process, the application server can create multiple instances of the stateless session bean that hosts your JCd and thereby multiple instances of your JCD class will be created. If these are no longer needed, the application server can destroy them.
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When your JCD's are started by a JMS message (this is when your JCD's implement the JMS receive web service), you can configure in the connectivity map how many instances of your JCD can be started concurrently by the application server. When double clicking the configuration block on the JMS inbound connection you can specify two options:
- Connection Consumer or Serial mode: multiple instances can be started when multiple messages are available or not
- Server session pool size: how many instances can be created.
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If you Java collaboration is exposed as an external callable web service, the stateless session bean will be called by the servlet, if your collaboration is called from en eInsight business process, the stateless session bean will be called by a message driven bean that is triggered from the eInsight BPEL engine."
Daher können 1 oder mehrere Instanzen einer JCD existieren, sogar 0 wenn die Aktivität sehr niderig ist.
