Oracle BPEL process engine is a container that provides standards for assembling, developing, and executing synchronous as well as asynchronous services into end-to-end business processes in the SOA Infrastructure. When the soa-infra
application is started, it initializes the BPEL engine in a stateless manner and loads composites from the MDS repository. If the composite contains any BPEL components, it targets them to the BPEL engine. At runtime, the BPEL engine waits for requests from different channels, such as messaging sources, databases, web services, and so on, and uses a Dispatcher
module that maintains an in-memory logical queue containing units of work to process the incoming messages from these binding components. The BPEL process engine saves the process execution state in the dehydration store through a persistence module based on Oracle TopLink and hence there is no in-memory state replication required. The audit framework` continuously audits the work being processed by storing process execution information in the database.
Oracle Enterprise Manager Fusion Middleware Control allows you to perform key administration tasks, such as monitoring instances, recovering from faults, manually recovering (BPEL) failed messages, and configuring properties for the BPEL Service Engine. It also provides useful statistics and performance monitoring metrics for the engine. Figure 7.27 shows a typical BPEL Engine landing page that can be accessed by navigating to SOA Infrastructure | Service Engines | BPEL. Note that the engine executes the OrderNotificationProcess
and OrderProcessing
components that are part of the OrderBookingComposite
application. The service engine dashboards have changed in Oracle Enterprise Manager Fusion Middleware Control 12c. Instead of showing a view of all instances and faults, it only shows a summarized view of deployed components, statistics of the components, and recoverable instances. Key administration tasks performed from the BPEL service engine dashboard include:
Let's have a look at the following screenshot:
The BPEL service engine is the heart of the Oracle SOA Suite infrastructure. The runtime behavior of the engine and the instances executing on it largely depend on its property configurations. It is therefore essential for administrators to understand their functions and be able to alter them when needed. Configuration properties such as audit level and audit trail threshold, automatic recovery for BPEL processes, master node recovery scheduling, automatic recovery attempts for invoke and callback messages, and callback message order preservation are all used by the BPEL process service engine during processing of BPEL process service components. These properties can be accessed and modified by navigating to soa-infra (soa_server1) | SOA Infrastructure | SOA Administration | BPEL Properties.
A few of the BPEL service engine properties are described in the following table:
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