Data Transformation Engine Intelligent Business Integration Reference Guide

Chapter 3 - Methods of Execution Event-Driven Execution Model

Intelligent Business Integration Reference Guide

Event-Driven Execution Model

The event-driven execution model relies upon the Mercator Event Server to

coordinate the triggering of map threads based upon either input event or time

event triggers.

Event Server Architecture

The Event Server architecture is an event-driven software model executing maps.

Systems contain maps supporting a system data flow that is specified by using the

Integration Flow Designer.

An Event Server runs on a server platform and can manage one or more systems

concurrently. Event Server functionality is based on the following premises:

♦ The event manager sub-component of the Event Server controls the initiation

of maps based on sources that a map subscribes to.

♦ The resource manager sub-component of the Event Server synchronizes shared

data and timing interfaces among heterogeneous sources and targets.

♦ Maps publish data that result from the content transformation of source data.

♦ Maps are transactional processes with each map having its own error detection

and recovery procedures.

♦ The Event Server runs as a single process with multiple threads. An associated

process monitors input source resource changes.

Event Server Watches and Triggers

The set of events that initiate a map within a system is called a watch. Each event

that contributes to the initiation of a map is called a trigger. When the resource

(file, database, or message queue) that is an input to a map changes state

(created or modified), this input event can cause the Event Server to initiate a

map.

The Event Server starts maps based on triggers that you identify using the

Integration Flow Designer. In some cases, there may be multiple triggers that

must collectively exist before a map is initiated. The Event Server manages the

coordination of these events to ensure that the correct set of circumstances have

occurred before a map is initiated.

Data sources using database adapters can serve as input event triggers that are

defined in the Database Interface Designer, enabled in the Integration Flow

Designer, and executed by an Event Server.