osb exception handling logging - ofm canberra september 2014

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OSB Exception Handling & Logging

Joey WongSolution ArchitectOracle Sydney


Exceptions


Exception HandlersFour types of error handlers:

• Stage

• Pipeline

• Route

• Service


Guidelines• Easier to handle specific errors at lowest

level.

• Handle more general default processing of errors using higher level error handlers.

• Good practice to explicitly handle anticipated errors in pipeline.

• Allow service-level handler to manage unanticipated errors.


Stage Error Handler• Use dedicated stage for each specific part

of the message flow.

• Allows very specific types of errors to be caught.

• Enables greater level of control over error processing.


Pipeline Error Handler• Sites above the stage error handlers.

• Exceptions re-thrown in a stage error handler will be propagated to the pipeline error handler.

• Request pipeline error handler is typically the result of malformed incoming request messages of bug in the request path.


Route Error Handler• Most errors seen by OSB happen here.

• Error handler is responsible for putting the fault message back into the SOAP body and forwarding the fault to the response message flow.

• Error message should be logged/alerted.


Service Error Handler• Always account for unanticipated errors.

• Enables unhandled exceptions at the stage, pipeline or route level to be caught and handled.

• Should be used for unanticipated errors.

• Bad practice to use this error handler to process all errors.


Common Error Handler• Depending on the type of exceptions that can be caught, you may find error handling

code is duplicated.

• May be more efficient to write a common error handling service.


Error Behavior• Errors are handled differently depending on how the service is called.

• Do you want to roll the transaction back for an asynchronous proxy?

• Do you want to send a fault back in response for a synchronous proxy?


Synchronous Errors• Synchronous transports like HTTP must

contain “Reply - With Failure” action.

• This send the fault back in the response to the consumer.

• Message flow terminates, no additional actions or error handlers will be executed.


Asynchronous Errors• Asynchronous transports like JMS must

contain “Raise Error” action.

• Similar to a rethrow in Java, causing the transaction to be rolled back.

• Raise Error action will be caught by a higher level error handler.


Logging


Logging Types• Log

• Alerts

• Report

<Sept 24, 2014 2:08:33 PM PDT> <Error> <OSB Logging> <Oracle-000000><[PipelinePairNode1, PipelinePairNode1_request, show text info, REQUEST]Text contents are: This is the file a.txt END><Sept 24, 2014 2:08:33 PM PDT> <Error> <OSB Logging> <Oracle-000000><[PipelinePairNode1, PipelinePairNode1_request, show text info, REQUEST]File name is: ftp_in/a.txt><Sept 24, 2014 2:08:33 PM PDT> <Error> <OSB Logging> <Oracle-000000><[PipelinePairNode1, PipelinePairNode1_request, show text info, REQUEST]Text contents are: This is the file b.txt END><Sept 24, 2014 2:08:33 PM PDT> <Error> <OSB Logging> <Oracle-000000>< [PipelinePairNode1, PipelinePairNode1_request, show text info, REQUEST]File name is: ftp_in/b.txt>


Guidelines• Establish logging requirements before starting development.

• Logging usually doesn’t need to include the entire body of the payload.

• Set appropriate logging levels.

• Error handlers should log at level “Error”.

• Dedicated OSB log file.

• Reporting action is heavy on resources. Use sparingly for Audit purposes.

osb exception handling logging - ofm canberra september 2014

Technology

oracle andor

error message

service error handler

route error handler

common error handler

error handlingcode

error behavior errors

stage error handlers