Let's consider each of these advantages in more detail.

Java for Programmer Productivity
Corporate IT managers are always on the lookout for ways to lower costs and do more with less. On the mainframe this goal presents unique challenges. In most cases mainframe applications run critical business functions and reduced development costs can represent significant savings. However, the tools and techniques in use are measured in decades. Many of the efficiencies and advances in software development have not made it to the mainframe, which is inflexible, proprietary rather than based on open standards, and often ill-suited to the rapid changes required in today's IT environment.

For many years software and tool vendors have been touting various products and solutions to make developing applications on the mainframe more efficient, easier, and less costly. As a programming language, Java combines platform independence with a number of advantages to address this requirement: it's easy to learn, there are a number of training services readily available, and there are a broad range of tools and aids for the developer. Java also lays the foundation for Java 2 Enterprise Edition (J2EE), a suite of services and APIs for building applications that leverage Web access, database and transaction support, and a robust component model. The ideal model is one that provides the power, productivity, and platform of Java and J2EE in a mainframe deployment model. WebLogic Server to the rescue!

Another key advantage of running J2EE with WebLogic Server on the mainframe is the removal of any reliance on proprietary software packages. A traditional weakness of mainframe computing is the use of vendor-specific software languages, applications, and tools. Few programming environments on the mainframe support the notion of objects or components. The costs and risks associated with replacing a vendor's product can include major rewrites of existing applications or implementing totally new applications. Deploying on WebLogic Server alleviates this problem by delivering a standards-based, component foundation more akin to the "plug-and-play" models popular today.

Platform Consolidation
For as long as most of us can remember, folks have been looking for ways to move applications off the mainframe - minis, Unix servers, Intel servers running Windows, etc. However, a funny thing happened in the past few years as corporations struggled with the "sunk cost" tied to the big iron. Organizations found that it makes sense to consolidate applications onto the mainframe instead of the other way around. IBM has made great strides in modernizing the mainframe with support for Java and Linux, and the mainframe delivers an unmatched level of 24X7X365 availability. Many businesses find they can dramatically reduce their total cost of ownership by relocating distributed applications onto mainframe hardware servers.

Why has this happened? The primary reason is that the work done by multiple distributed servers can be consolidated onto a single mainframe. The mainframe supports applications that are vital to continuing business operations; thus, the operating costs associated with maintaining the mainframe are relatively fixed. On the other hand, adding more distributed Unix or Windows servers to a cluster or server farm usually requires adding more administrators to manage them. To expand an existing application or deploy a new application, the IT executive can either 1) buy more equipment and hire new people to manage it, or 2) deploy to the existing mainframe and leverage existing system management personnel. Although there often are other factors to consider, one trend that is gaining momentum is consolidation.

Better Resource Utilization
Another key cost reduction driving application deployment on the mainframe is to more efficiently utilize the resources we already have available to us. We've discussed the reality of operational costs associated with maintaining the big iron. In addition, those costs are relatively fixed even if the hardware isn't running at maximum capacity. In many environments today the mainframe has underutilized resources - CPU cycles, memory, or disk - yet the organization's costs don't reflect this. More efficiently utilizing these resources lowers operational costs by doing more with less - the CIO's main objective.

In many production environments distributed resources are often underutilized. For example, a recent review of a production cluster of Unix servers found that the servers were operating at 15-20%. If mainframe resources are available it's often easier to consolidate these under-utilized servers onto a logical partition under z/OS or z/Linux. While delivering the same overall performance, consolidating these servers can result in savings that include lower administrative costs; a simpler, less complex deployment environment; and high quality-of-service and operational properties.

Closer Access to Critical Business Systems
Contrary to some wishful thinking, the predominant hardware platform for many critical business systems in use today is still the mainframe. With the fears and hype surrounding Y2K behind us, there may be little incentive to replace existing applications as long as they deliver business value at minimal incremental cost. However, more and more personnel, systems, and customers require information stored in these legacy systems. Providing this access in a way that is secure, and transactional, without introducing unnecessary complexity, is key to delivering real business value.

WebLogic Server provides a number of key advantages that make it easier to access legacy systems and data from Web and distributed solutions. WebLogic Server makes J2EE, including Enterprise JavaBeans, available on the mainframe. Through J2EE, mainframe services can be exposed without requiring distribution of mainframe client APIs. Access is extended to Java applications via a stateless session EJB or message-driven bean. Web services permits access to these same EJB components from any distributed program via a SOAP call using an interface defined in WSDL. When deployed on the mainframe, Java components have "local" access to mainframe applications, without expensive network latencies or the complexity of heterogeneous hardware deployments.

In addition, the basic services of WebLogic Server on the mainframe can be extended with WebLogic Integration, providing standards-based application access using the J2EE Connector Architecture, business process management, data translation and transformation, and business-to-business messaging. WebLogic Integration is built on WebLogic Server and leverages the underlying J2EE services such as Enterprise JavaBeans and Java Messaging Service. WebLogic Integration is certified for deployment on the mainframe as well as on various Unix, Linux, and Windows systems.

WebLogic Server for the Mainframe
WebLogic Server provides a complete suite of the J2EE standard for distributed Java applications. Included in the server is support for Java Server Pages and servlets; Enterprise JavaBeans; RMI for communication, transactions, naming and directory services; Java Messaging Service (JMS); and other J2EE facilities. The J2EE model is extended with key features that make it uniquely suitable for large-scale production deployments, including clustering, in-memory session and object persistence, entity bean caching, support for the J2EE security model, and a comprehensive administrative foundation including integration with third-party solutions.

WebLogic Server for the mainframe offers this same suite of services on a Java Virtual Machine running natively in either z/OS or z/Linux systems. Specifically, WebLogic Server supports four deployment models for the mainframe:

• Running directly on a virtual machine
• Running in a Logical Partition (LPAR) directly on the hardware
• Running in a Virtual Machine guest under Linux
• Running in a Unix or Windows NT/2000 environment with the mainframe as a data server

An often asked question is why would someone want to run products from BEA on the mainframe? What does BEA know about parallel sysplex, about z/OS and z/Linux, about data sets and copy books, about VTAM and NCP gens, about using the Workload Manager? While BEA is the leader in distributed transaction processing, is there a compelling reason to run WebLogic Server on the mainframe? What about other companies and their application servers, particularly ones that have some history with the mainframe?

These questions actually point out many of the reasons BEA is the best choice for J2EE on the mainframe. WebLogic Server offers the following advantages for mainframe J2EE solutions:

• Common code base across heterogeneous hardware platforms
• Application performance, including tools and utilities to aid in tuning
• Extensible architecture to ease integration with existing applications and databases

A key advantage of WebLogic Server is that the product running on the mainframe is from the same code base as other environments. Java was designed to offer platform independence and WebLogic Server builds on this. Applications developed for WebLogic Server in a distributed environment can be deployed directly on the mainframe without requiring any code modifications or detailed knowledge of mainframe systems. Developers familiar with current Java development tools and strategies can build applications for deployment directly to the host. Existing design patterns and best practices can be implemented regardless of the underlying operating system and hardware. Since the code base for WebLogic Server is the same across all platforms, the product's maturity and stability can be leveraged to ensure high availability, reliability, and scalability. The result is lower cost of development and training, and lower risk associated with the corresponding deployment.

Another advantage is in the area of application performance. Benchmarks have shown that applications that require a large and relatively complex deployment on distributed servers can be run on a few mainframe partitions, leveraging existing hardware and system management resources. WebLogic Server can be configured to use the Workload Manager (WLM) on the mainframe to efficiently manage the deployment for maximum performance. Third-party tools, such as Wily Technologies' Introscope, Candle, CA Unicenter, BMC, and Velocity Software can be used to tune the application's performance, identify bottlenecks, and diagnose application problems.

One of the benefits of using WebLogic Server for J2EE applications is the clustering support. Multiple replicas of an application can be clustered together for redundancy, failover, and scalability. Application objects deployed on the mainframe can be clustered with other servers, including heterogeneous hardware types. Within the same cluster an application can be deployed on the mainframe using z/Linux, Solaris, HP-UX, Windows 2000, and others. WebLogic Server also provides an administrative domain in which all the distributed resources can be managed as a single system image.

A third advantage is the ease with which it can be integrated with the existing resources and applications. WebLogic Server can be integrated with the RACF security environment to offer consistent services and can be configured through the Tivoli Policy Director. It integrates with MQSeries by including the MQ Java APIs and coding directly to the MQ_* verbs in the application code. In addition, WebLogic Server can include MQSeries in distributed transactions with full two-phase commit support. It coordinates these transactions using the industry-standard XA protocol. WebLogic Server can be integrated with mainframe databases using the vendor-provided JDBC drivers or using products such as the CrossAccess eXadas Data Integrator or Neon Systems' ShadowDirect. Finally, WebLogic Integration extends the WebLogic foundation for adapters based on the J2EE Connector Architecture, business process management, data translation and transformation, and business-to-business message exchanges.

Summary
We've examined some of the business benefits of deploying J2EE applications on the mainframe, including the use of Java tools and patterns for developer productivity and lower cost, server consolidation to lower total cost of ownership, consolidation of distributed servers onto a mainframe with available resources, and shortening the access to critical data and business applications. We've briefly covered WebLogic Server on the mainframe and some of the reasons to select BEA for mainframe deployment of J2EE-based applications.

The next article in this series will detail the specifics of deploying WebLogic Server in mainframe environments, including z/OS and z/Linux, and detail the useful tools and services available. The third article will address some of the production applications using WebLogic Server on the mainframe, as well as some tips and helpful hints.