Orbacus Notify
Orbacus Notify is the perfect foundation for your event-based Applications. With new features like event filtering, structured events and run-time system management, Orbacus Notify delivers all the flexibility and power you need to get your next project off the ground quickly and easily. Fully compliant with the CORBA Notification Service specification Orbacus Notify provides a powerful middleware platform for your distributed systems. Contact our sales team for information and pricing.
Event Service Compatibility
Orbacus Notify is fully backwards compatible with the OMG Event Service, providing a smooth migration path for your existing event service clients.
Delivery Models
Orbacus Notify supports the canonical push and pull delivery models, and hybrid combinations.
Event Delivery
To maintain backwards compatibility with event service clients, Orbacus Notify supports untyped event delivery. In addition, Orbacus Notify introduces structured event and sequence structured event delivery.
Structured events allow you to specify per event QoS and compose events consisting of filterable and opaque fields. Since structured events are actual IDL types, the filterable fields are visible to Orbacus Notify and are used during event filtering.
For small, individual events the per-method invocation overhead may impact overall performance. If your clients frequently transfer small events you may want to consider using sequence structured events. In this scheme, one or more structured events are batched together and transferred in a single method invocation. Suppliers have full control of sequence composition and can accumulate an arbitrary number events before actual delivery. Likewise for consumers, Orbacus Notify allows you to configure the maximum batch size and pacing interval for event delivery.
Filtering
Structured events are composed of an event header and event body, where the body consists of filterable and non-filterable fields. Through the use of mapping filters, Orbacus Notify supports the mapping of event header lifetime and priority property values. In effect this mapping changes the way in which the event is handled within Orbacus Notify.
Forwarding filters allow you to filter event flow at various points throughout the service, ensuring unwanted events do not waste valuable network bandwidth on the consumer side.
Quality of Service and Admin Properties
Orbacus Notify supports all the standard QoS and Admin properties and introduces proprietary properties to overcome the shortcomings inherit in the Notification Service specification. The Orbacus Notify proprietary properties address the following issues:
- event retry due to failed communications
- pull model pull interval
At a wider scope Orbacus Notify may be configured to provide maximum performance under various system configurations ranging from few suppliers and consumers to many external clients. Orbacus Notify may also be tuned based on competing requirements such as event reliability and event throughput.
Subscription Sharing
Structured events are classified (in the event header) by domain and type. Orbacus Notify clients may use this information to ensure that unwanted events are never produced in the first place. Each Notification channel maintains an aggregate list of offered event types and subscribed to event types. Suppliers may add or withdraw types from those being offered while consumers may add or withdraw subscriptions. Any change to the total event offering is propagated to consumers while subscription changes are propagated to event suppliers.
Event Translation
Event suppliers and consumers need not be of the same type in order to communicate events. Orbacus Notify has full support for event translation, in which events are "minimally enveloped" according to consumer requirements. That is structured events from a structured supplier are delivered to untyped consumers in a CORBA::Any. Similarly, untyped events are presented to structured consumers within the remainder-of-body field of a structured event.
