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Overview of the Verastream Host Integrator Development Process
Technical Note 40004
Last Reviewed 21-Jul-2006
Applies To
Verastream Host Integrator version 5.0 only
Summary
Figure 1 – Host application modeling.
Figure 2 - Legacy data is available via a web application.
Figure 3– Host Integrator Server provides concurrent access to enterprise systems.
Figure 4 – Host Integrator dynamic load balancing
Technical Note 40004
Last Reviewed 21-Jul-2006
Applies To
Verastream Host Integrator version 5.0 only
Summary
With Verastream Host Integrator, the process of integrating enterprise legacy systems into Java, web, or other integrated development environments is accomplished by building a model of the legacy application that is used to create a custom web or client/server application, which can then be deployed. The three well-defined steps involved in this process are described in this document.
Step 1. Building and Deploying the Model of a Legacy Application
Host Integrator uses a process known as host application modeling to integrate legacy data into web and client/server applications without making any changes to the existing host system. Using the Host Integrator Design Tool, both software developers and other users can create an object model of a host application. They step through the host application to tag host screens and the fields on these screens that contain data to be integrated into a new application. The model contains all of the information required for Host Integrator to connect to the host, recognize screens and data fields, and navigate the application.
Figure 1 – Host application modeling.Host Integrator Design Tool creates a database paradigm for screen-based legacy applications, allowing an application developer to treat a legacy application as a database and use standard database access methods, like JDBC, to access legacy data.
Using the Tables feature, a host application developer can abstract a host application so that client applications can perform abstraction-level queries using a subset of the industry-standard SQL or JDBC. This makes it possible to access the data in host applications through queries even if the host application is not designed to respond to SQL or JDBC queries.
Verastream Host Integrator allows a developer to integrate host systems into client/server and web applications 10 to 15 times faster than with traditional toolsets. New applications can be partitioned to support multi-tier client/server architecture and can be deployed across a wide variety of operating systems and hardware platforms.
Step 2. Building a New Web or Client/Server Application
Once the model of the legacy application is complete, the Administrative WebStation is used to add the model to the Host Integrator Server. The model then becomes immediately available for the developer. Developers use a Host Integrator connector to create a new web or client/server application using their preferred development tools, such as Java, Visual Basic, Visual C++ and the Host Integrator Software Development Kit for the selected development environment. When a new application runs, it uses the Host Integrator API’s object library to access host data through a Host Integrator Server.
Figure 2 - Legacy data is available via a web application.In addition to various Java development environments, such as Visual Café, JBuilder, Visual Age, Java Studio, JFC, and JDK, Host Integrator SDK for Java provides seamless integration into powerful application servers. Host Integrator allows developers to combine data from multiple legacy applications and multiple hosts into a single web application or web page.
Step 3. Deploying the New Application to the Enterprise
Once the development of the new web or client/server application is complete, it can be deployed in an enterprise operating environment using the multi-tier Host Integrator Server.
Figure 3– Host Integrator Server provides concurrent access to enterprise systems.Host Integrator Server’s multi-threaded architecture is designed to support large numbers of users in transaction-intensive environments. A single Host Integrator Server can provide concurrent access to different web and legacy systems in the enterprise, including IBM 3270 and 5250, as well as VT and HP3000 applications.
Host Integrator Server supports all mainframe-based security packages. In addition, it offers its own multi-level security, which can be tied to the security schema of the selected deployment platform (Windows 2000/2003, UNIX, or Linux).
Host Integrator Server provides dynamic load balancing and failover for multiple Host Integrator Servers on the network.
Figure 4 – Host Integrator dynamic load balancingUsing Host Integrator Administrative WebStation, system and network administrators have a single point of management and control for multiple Host Integrator Servers and Host Integrator Domain Servers in the enterprise. The Administrative WebStation facilitates the development and administration of web and client/server applications by providing real-time access to key server information. While any in-place mainframe security system (RACF, ACF-2, TopSecret, e.g.) remains fully in force, Host Integrator Server’s comprehensive audit-trail facility and security options give system administrators an extra level of protection and control over their enterprise operations. In the configuration shown above, Verastream Host Integrator Server offers fault tolerance and load balancing for Internet and Intranet usage.
