Integrated Web Application Server for IBM i - Frequently asked questions

This page answers frequently asked questions (FAQs) about the Integrated Application Server for i. The FAQ answers questions regarding the features of the product as well as comparisons to WebSphere Application Server, WebSphere Application Server Network Deployment (ND), and Apache Software Foundation (ASF) Jakarta Tomcat servlet engine (hereafter referred to as ASF Tomcat).

• What is integrated application server for i?
• Why would I want to use integrated application server?
• How can I obtain integrated application server?
• What products use the integrated application server?

What is Integrated Application Server for i?

The integrated application server for i is a lightweight Java application server integrated into the operating system. The integrated application server contains an Open Services Gateway initiative (OSGi)-based web servlet container that is readily accessible and provides a flexible foundation for developing jsp and servlet-based Java applications. The integrated application server delivers a clear path to the advanced capabilities of the WebSphere middleware portfolio.

Why would I want to use integrated application server?

Some of the reasons you might want to use integrated application server for i:

• You embed ASF Tomcat in your application today. With the integrated application server you would not have to embed ASF Tomcat with your application.
• You have limited system resources that prevent you from optimally running WebSphere Application Server.
• You do not need more security, n-tier deployment environment, JMS & EJB programming model support, or WebSphere Application Server ND clustering.
• You want to deploy simplified database applications with one database connection.
• You want to deploy traditional servlet and JSP applications.

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How can I obtain integrated application server?

The following prerequisites are required to be installed on the system in order to use the integrated application server for IBM i support:

• Extended Base Directory Support - base option 3 of operating system
• Host Servers - base option 12 of operating system
• Qshell - base option 30 of operating system
• PASE - base option 33 of operating system
• Digital Certificate Manager - base option 34 of operating system
• IBM HTTP Server for IBM i
• IBM Technology for Java SE 8 64 bit (and any newer Java Runtime Environments you might want to use)

After loading the products, ensure you load the latest HTTP group PTF.

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What products use the integrated application server?

Some of the products that use the integrated application server include:

• The IBM i web administrative interfaces
• The integrated web services server
• Db2 Web Query for i

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• Why use the integrated application server versus ASF Tomcat?
• Why use WebSphere Application Server versus the integrated application server?
• What are the differences between how database access is supported by the integrated application server versus ASF Tomcat & WebSphere Application Server?

Why use the integrated application server versus ASF Tomcat?

The latest version of the integrated application server is based on the Liberty profile, a recently-developed dynamic profile for WebSphere Application Server. The profile enables rapid development and deployment of applications in a simpler and lightweight manner.

Liberty and Tomcat provide a basic servlet engine, but can also be grown to provide more Java enterprise services and related services. With Liberty, those services have already been integrated with the Liberty kernel, so the services have a common configuration file, log outputs, and more. With Tomcat, the user performs the integration of third-party libraries.

The Liberty profile default configuration is small and is simpler—unlike Tomcat, which has most of its functionality enabled by default. Liberty features are enabled by the deployed applications as needed and when needed, keeping the server footprint as small as possible.

Tomcat has a slightly faster restart, although both servers start in less than three seconds. Liberty requires fewer restarts due to its dynamic configuration updates. Memory footprints are comparable and will vary in both cases, depending upon the features that are configured (Liberty) or libraries added (Tomcat). The Liberty shared library support has the potential to make significant footprint reductions when applications need different versions of the same library.

Production throughput for the JSP/JDBC workload is about 30 percent higher for Liberty, which could make Liberty a better choice where high-volume performance is important.

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Why use WebSphere Application Server versus the integrated application server?

Use WebSphere Application Server if you want the following:

• You need higher availability or more scalability
• You use more than one JNDI (Java Naming and Directory Interface) connection
• You want to use the built-in messaging engine based on WebSphere MQ, or the Java Based Messaging Engine
• You need more of the robust features in WebSphere Application Server such as
  • Support for full J2EE programming model
    • EJB's, JMS
    • JDBC (integrated app server has limited namespace, only allows one JNDI connection)
  • Support for full & extended J2EE packaging model
    • WAR, EAR, RAR files
    • IBM extensions (extended deployment descriptor, annotations, etc.)
  • Support for n-tier deployment model
    • HTTP server, application server, DB on same or different machines
    • Cross platform, heterogeneous capabilities
      • Run tiers on different servers, operating systems, etc.
      • Support for Db2, Oracle, MySQL, etc. database access
  • Support for full range of security options (HTTP server, web application, Java)
  • Support for an integrated test server environment for iterative development

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What are the differences between how database access is supported by the integrated application server versus ASF Tomcat & WebSphere Application Server?

The integrated application server documentation uses the terminology database connections. WebSphere Application Server documentation uses the terminology data sources. Both refer to the same thing.

A data source represents a specific database that is used by one or more applications installed in your application server. Data sources provide connection pooling and a JNDI name, which can be used by applications to access the data source.

The integrated application server supports a single JNDI name source. WebSphere Application Server supports multiple JNDI name sources. You are only allowed one JNDI database connection with the integrated application server. Applications with multiple JNDI names and connections will not be supported on the integrated application server.

The integrated application server connection pooling support is done by Apache commons database connection pooling. WebSphere Application Server connection pooling is done by WebSphere connection pooling.

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• What types of web applications will be supported by the integrated application server?
• Is there an option to modify class paths for applications when deploying to the integrated application server?
• Will a servlet that is created run on the integrated application server and WebSphere Application Server without modification?
• Can IBM WebSphere Portal be run on the integrated application server?
• Can applications created with IBM WebFacing Tool be run on the integrated application server?
• Can applications created that uses WebSphere® Host Access Transformation Services (HATS) Toolkit run in the integrated application server?
• Can you deploy and run an application created with Rational Business Developer Extension (RBDe) Enterprise Generation Language (EGL) on the integrated application server?
• Can you target integrated application server when creating dynamic web projects when using WebSphere Development Studio Client for System i or Rational Application Developer?
• What performance tools can be used to optimize applications running on the integrated application server?

What types of web applications will be supported by the integrated application server?

The integrated application server supports web archive (WAR) files.

Is there an option to modify class paths for applications when deploying to the integrated application server?

Yes.

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Will a servlet that is created run on the integrated application server and WebSphere Application Server without modification?

In general, yes, most servlets should run on either application server. However, the integrated application server supports only one JNDI connection. Applications with multiple JNDI names and connections will not be supported on the integrated application server.

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Can IBM WebSphere Portal be run on the integrated application server?

No.

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Can applications created with IBM WebFacing Tool be run on the integrated application server?

Yes. However, applications created with IBM WebFacing Tool have support for high availability and hot failover through the use of WebSphere Application Server Network Deployment (ND). Use WebSphere Application Server ND if high availability and failover are required. In addition, use WebSphere Application Server or WebSphere Application Server ND if J2EE security is required.

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Can applications created that uses WebSphere® Host Access Transformation Services (HATS) Toolkit run in the integrated application server?

No.

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Can you deploy and run an application created with Rational Business Developer Extension (RBDe) Enterprise Generation Language (EGL) on the integrated application server?

No.

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Can you target integrated application server when creating dynamic web projects when using WebSphere Development Studio Client for System i or Rational Application Developer?

No.

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What performance tools can be used to optimize applications running on the integrated application server?

You can use Collection Services for heap and garbage collection. You can use tools to analyze applications such as Job Watcher and Performance Explorer (PEX) Analyzer for collecting and Performance Trace Data Visualizer (PTDV) for analyzing performance data.

In V6R1, you will also be able to use Web Performance Advisor, a part of IBM HTTP Server for i, to help tune your application.

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• What are the options to administer the integrate application server?
• Can an API be used to create an instance of the integrated application server and install applications?

What are the options to administer the integrated application server?

The preferred way to administer the integrated application server is by using the Web Administration for i GUI. The Web Administration for i uses the default web administration port of 2001.

Can an API be used to create an instance of the integrated application server and install applications?

Yes, there are scripts that callable from Qshell found in directory /QIBM/ProdData/OS/ApplicationServer/bin.

• What are the general differences between integrated application server and WebSphere Application Server?
• What are the differences in database features of the integrated application server and WebSphere Application Server?
• What are the differences in APIs that are supported by the integrated application server and WebSphere Application Server?
• What are the differences in administrative features that are supported by the integrated application server and WebSphere Application Server?
• What products are supported on integrated application server versus WebSphere Application Server?

What are the general differences between integrated application server and WebSphere Application Server?

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What are the differences in database features of the integrated application server and WebSphere Application Server?

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What are the differences in APIs that are supported by the integrated application server and WebSphere Application Server?

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What are the differences in administrative features that are supported by the integrated application server and WebSphere Application Server?

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What products are supported on integrated application server versus WebSphere Application Server?

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