Taking Care – Error Handling - Applied SOA Patterns on the Oracle Platform - page 519

• Depending on the service location and use case, we can try basic recovery opera-
tions such as Retry (see the following figure) on Business Service, which is un-
der the Transport tab. Despite its simplicity, the Retry operation must be applied
with extra care, after the analysis of fault types. For instance, we can double the
transaction if the service in not idempotent and our timeout interval is not adjus-
ted according to the processing time.
Maintaining service policies on OSB
As the name service edge denotes, here we have to apply a lot of message handling and
security policies as well. Not all of them are directly EH-related, but all of them contribute
to the composition's resiliency. Another thing that is apparent from the preceding figure is
that they are different policies from what we discussed while explaining SCA EH. Well,
complete Policy Centralization is not really achievable in OFM, and we have already
mentioned that; however, we are quite capable to maintain the desired level of centraliza-
tion per SOA framework. At least two policy types are essential for the OSB implementa-
tion: WSM and standard (almost) WS-Policies. You can see a list of the available default
policy resources in the preceding screenshot; they are applicable for Business and Proxy
services (see the Policy tab).