Database Reference
In-Depth Information
• Compute resources
• Web server(s)
• WebLogic Application Server(s): For example, Oracle SOA
Suite server
• Database server(s)
• Storage Area Network
SOA environment
Compared to a typical web application environment, usually the SOA environment
consists of many systems and/or applications. Reusing the existing applications,
also known as legacy applications in a loosely coupled way to achieve the business
agility/flexibility, is one of the goals of implementing SOA.
The SOA environment is highly available only when all its component systems either
meet or exceed the business service's availability SLAs. We need to ensure that all
the endpoint systems orchestrated by BPEL are capable of meeting the availabil-
ity uptime SLAs. The SOA integration points are designed and validated to recov-
er from the external sub systems and service outages caused by planned and un-
planned maintenance windows for pre-defined durations. We should clearly articu-
late and identify the external sub systems and services that directly impact our ser-
vice'savailability uptimeSLAs. Theend-to-endsynchronoustransaction's availability
is immediately impacted by a sub system's outage.
It is highly recommended that for the synchronous transactions invoked, consider
implementing the retry logic until the SOA core system successfully completes the
transaction. Also, for asynchronous transactions, store the critical information per-
manently until the SOA core system processor is able to complete the transaction
successfully.
As shown in the following diagram, a user transaction may fail if one of the systems
within the SOA environment is not available. Hence, it is important that we design
the availability at all the components of a SOA system instead of just focusing on the
BPEL/SOA Suite. The SOA BPEL system's availability is dependent on the external
service's endpoints.
