High Availability in InboundOutbound Operations

10-14 Oracle Fusion Middleware Users Guide for Technology Adapters The JCA inbound retry mechanism is commonly used by all adapters, in general, whereas the message backout queue mechanism is used only by the Oracle MQ Series Adapter. If you specify the BackoutQueueName property in the .jca file, only then the Oracle MQ Series Adapter will use the message backout queue mechanism to retry. By default, the JCA inbound retry mechanism is used for retry.

10.3.9.1 JCA Inbound Retry Mechanism

The Oracle MQ Series Adapter supports a pull model for connecting to the back-end application for receiving events. Connection-related issues are considered recoverable and most inbound adapters keep retrying until the adapters are able to establish connection with the EIS. In case of Oracle MQ Series Adapter, a message not being able to put to a queue is also retriable. For more information about retry mechanism, see Section 2.22, Error Handling .

10.3.9.2 Message Backout Queue

Backout Queue is a queue for putting rejected messages from an inbound queue. The inbound adapter checks for the backout count of the messages and if this count exceeds the MaximumBcakoutCount value, then the adapter puts the messages to the specified Backout Queue. This mechanism is used by the Oracle MQ Series Adapter to handle inbound retries for the rejected messages. If you specify the BackoutQueueName property in the .jca file, then Oracle MQ Series Adapter uses the message backout count for retries. You can specify the maximum retries using the MaximumBackoutCount property. The default value for this property is infinite. If you do not specify the MaximumBackoutCount value along with the BackoutQueueName, then the adapter retries infinitely. The adapter does not consider JCA retries specified in composite.xml when the BackOut Queue properties are specified. The BackoutRetries property must be set to specify the number of retries for delivering the message to the Backout Queue with retry interval set using the BackoutRetryInterval property. The default value for BackoutRetries is 3 and BackoutInterval is 5 sec. If a message gets rejected even after the MaximumBackoutCount value is reached, then the adapter puts the message to Backout Queue. If Oracle MQ Series Adapter is unable to put the message to Backout Queue, then the adapter tries till the BackoutRetries count with the BackoutInterval time delay. If even after the BackoutRetries the adapter cannot put the message to Backout Queue, then the adapter deactivates the endpoint. You must also specify the name of the Queue Manager of the Backout Queue in the BackoutQueueManagerName property. You must not use this property if the BackoutQueue resides on the inbound queue QueueManager. Note: Both these methods of retry in the Oracle MQ Series Adapter are mutually exclusive operations. This means that the adapter can use only one mechanism at a time. In case both of the options are specified, then the Backout Queue option takes precedence.