Real Time Information Director User Documentation

Technical Overview of the Real Time Information Director
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Subscription Registration Interface
A user (shown in the upper right corner of the figure) uses the Subscription Registration
Interface to specify a subscription. A subscription has three attributes:
• A SQL Select statement, which defines the event in the data store that will trigger
the subscription
• A Java Messaging Service (JMS) topic or queue name. This name indicates
where the subscription server must publish the message. The configuration of the
Integration Server or Enterprise Application must specify a matching topic or
queue name.
• The name of the document to be delivered when the data store event occurs
The Subscription Registration Interface provides ways to browse among registered
subscriptions, delete a subscription, or reinstate a previously defined subscription.
All registered subscriptions are stored in a Subscriptions Store—a NonStop SQL table
where each row in the table corresponds to a subscription that has been registered with
the Subscription Server.
Subscription Server
A Subscription Server is the component that services a subscription.
When the Director application starts up, a Subscription Server instance (which is a startup
class in NonStop WLS) is activated for each registered subscription. Thereafter,
whenever a new subscription is registered, a Subscription Server instance is activated to
service the subscription. When an existing subscription is deleted, the corresponding
Subserv instances are deactivated.
When a subscribed event occurs, as defined by the SQL statement in the subscription, the
Subscription Server receives from SQL/MX all the database columns required to build
the message to the subscriber. For this function to work, all the data required by the
outgoing message must be in the Data Store, although not necessarily in the inserted
record that triggered the subscription. For example, if an incoming order from a
customer triggers an outgoing request to restock a shelf, some of the information required
for the restocking request will be pulled from elsewhere in the Data Store. The person
who tailors the data model to the environment must ensure that all fields required to
construct outgoing messages to subscribers—for example, every required field of every
requested IDoc--are present in the Data Store.
The subscription server assembles the message according to the metadata (Format and
Content Metadata in the figure), which is shared by the various components of the
Director.