Messaging is the exchange of information by two or more software applications. A message is a self-contained package of information.
Many Adaptive Server customers use messaging and queuing, or publish-and-subscribe systems in their own application environments. These applications are called message-oriented middleware. Often, the same application combines database operations with messaging operations.
Active Messaging simplifies the development of such applications, using Adaptive Server with Tibco Enterprise Message Service (EMS), EAServer Java Messaging System (JMS), IBM WebSphere MQ (MQ), and SonicMQ from Sonic Software.
EMS is the Tibco implementation of a Java Messaging Service
(JMS). Unless specified, JMS refers generically to Tibco EMS, EAServer
JMS, and SonicMQ JMS in this documentation.
Messaging systems allow senders and receivers to be detached. A messaging system can be asynchronous, in that an application can send messages without requiring receiving applications to be running.
JMS and MQ are APIs that define how clients communicate with message providers. The message sender and the message receiver both act as clients to the message provider.
Messaging systems are provided by message providers. The messaging provider can implement architecture that centralizes or decentralizes the storage of messages, or that is a hybrid of the two.
Active Messaging performs messaging operations within SQL statements, using built-in functions.
It also provides a way to capture transactions (data changes) in an Adaptive Server database and deliver them as events to external applications using either:
A JMS message bus, provided by Tibco, EAServer, and Sonic Software, or
The Message Queue Interface (MQI), provided by WebSphere MQ
