NonStop Systems Introduction

Requirements of ZLE Systems
NonStop Systems Introduction—527825-001
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Services and Applications
the APIs and protocols necessary to ensure that information is delivered to its intended
destination.
The primary advantage of products such as JMS and MQ Series is that they provide
for asynchronous transmission of data, both to and from the hub. With asynchronous
messaging, transactions are queued for entry into the database; the sending
application does not wait for confirmation that a transaction is complete, but is free to
continue with its processing tasks while messages are queued. Queued requests are
processed in order, and the response is processed when it is returned to the client.
With synchronous messaging techniques, the sender of a message waits for a
response indicating that the message has arrived at its destination before continuing its
processing. Asynchronous messaging eliminates the delay inherent in synchronous
messaging, and often results in faster response times.
Services and Applications
To enable diverse business applications to communicate with one another and with the
ZLE hub, the EAI layer of a ZLE system must provide a complex set of services,
including data transformation, business rules, and workflow. (Workflow or message
flow usually implies that when a certain event occurs, one or more business
applications must be notified. For example, when a user hits the Enter key in a SAP
application, a new order is entered, routed to a transformation server, and captured.
Then copies of the order are sent to various other business systems that need them.)
Another example of an essential EAI service is data conversion. When data is sent
from one application to another (through the ZLE hub), EAI must be able to convert the
data from the format of the sending application to the format of the receiving
application. To perform these and other essential services, a wide variety of software is
available from the leading EAI vendors. The ZLE system must support this software.
Support for open standards is also important for the ZLE applications running on the
hub. These ZLE applications are specialized applications that perform business-level
functions, such as fraud detection and customer relations and personalization. Many
third-party ZLE applications are available from companies such as Acxiom, Protagona,
MircroStrategy, and Trillium Software. The ZLE system must support these
applications.
Application Integration Frameworks
The role of the EAI layer of a ZLE system is to provide a framework for the integration
of business applications and for implementing essential ZLE services. At the core of
this framework is an application server. The application server provides many
essential services for application integration, including messaging, transaction
management, application management, load balancing, and high availability. The
application server also provides tools for developing and hosting new ZLE applications
and services.
Providing the services required for application integration is an enormous challenge.
As discussed earlier, the variety of applications that must be integrated is large. To