The specification for Corba IIOP-based asynchronous messaging that will be presented to the Object Management Group’s Dublin meeting in September won’t go as far as including the kinds of programming interfaces which middleware vendors had been pressing for (CI No 3,196). The goal of OMG’s messaging initiative is to specify how object-oriented applications using its Corba IIOP architecture can send and receive requests for action asynchronously via a store and forward mechanism which can also guarantee messages get delivered. Corba IIOP currently operates over synchronous connections which mean users can’t do other work while invocation tasks are being completed and doesn’t provide a guarantee or proof that a message has been sent or received by its intended destination. The OMG committee which is preparing the specification says the RFP should more properly have been called the asynchronous remote method RFP. Middleware companies selling messaging-based application services such as those represented by the Message Oriented Middleware Association (MOMA) think it’s important that a programming interface is exposed that provides developers with finer grain control such as being able to queue or de-queue messages. These types of services should be addressed by other OMG notification services, committee members say and should be handled by higher-level administration services. The specification will extend OMG’s IIOP Internet InterORB Protocol for messaging – as MIIOP is one suggestion – which the definition of IIOP is already able to accommodate. OMG offered to support an IIOP-compatible messaging protocol but MOMA declined, saying it isn’t a standards body. It’s thought unlikely MOMA would have been able to create a common technology from the multiple proprietary messaging protocols used by vendors in any case. Object request broker vendors are expected align their products with one or other of messaging products currently on offer. ISVs will have to upgrade programmes to take advantage of MIIOP’s asynchronous services. While ORB vendors are expected to have integrated broker/messaging products out around the end of the summer, the kind of out-of-the-box compatibility required by OMG is expected to take six months or so to be implemented in products.
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