| By Srinivasan Sundara Rajan |
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| September 17, 2012 08:00 AM EDT |
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8,156 |
Platform as a Service (PaaS)
Platform-as-a-Service (PaaS) represents a complete preintegrated platform offering for the development and operation of general purpose business applications. A fully preintegrated and standardized platform - offered in a multi-tenant mode as a managed service - means much less manual effort than installing and configuring middleware components in on-premise servers.
Enterprise architecture patterns and framework changed heavily during the last decade, the software / platform / framework upgrades eat up the major chunk of it budgets and leaving relatively smaller portion for business innovation.
One of the important goals of PaaS is to relieve the enterprises from the trouble of upgrades and concentrate on business value to clients.
Due to the above out-of-the-box features for enterprises, PaaS is considered an enabler for innovation. The following is a comparison of various PaaS platforms in general and in particular about Java EE PaaS platforms.
Windows Azure and PaaS for .NET
Ever since the beginning of this century comparisons between the platform capabilities of Java EE (Java Enterprise Edition) and Microsoft .NET is a common discussion in most of the decision points for the choice of enterprise platforms.
With the advent of Cloud, Microsoft has taken a lead with the Windows Azure PaaS (Platform as a Service).
From a platform perspective Windows Azure provides a complete list of options as available to .NET developers in an ‘On-Premise' setup, which includes:
- Full Support for .NET framework and languages like C#, Visual Basic
- Web Development using ASP.NET
- Distributed Processing using WCF (Windows Communication Framework)
- Enterprise database support with SQL Azure
- Data Access Services using ADO.net and LINQ
- Rich Internet Application Support using Silverlight
- Mobile Services for Windows 8 Development
Most key decision makers for Cloud enablement will be left with the questions on how good an equivalent is the Java EE platform.
Java EE PaaS Options
Java, a counterpart of the .NET platform, was earlier referred to as J2EE but is now called Java EE and it offers several enterprise class features for multi-tiered enterprise development. Java Platform, Enterprise Edition (Java EE) 6 is the industry standard for enterprise Java computing. Utilize the new, lightweight Java EE 6 Web Profile to create next-generation web applications, and the full power of the Java EE 6 platform for enterprise applications. Developers will benefit from productivity improvements with more annotations, more POJOs (Plain Old Java Objects), simplified packaging, and less XML configuration. The below is the comparison two major PaaS Offerings on Java EE.
- Google App Engine For Java (GAE For Java)
- Redhat Open Shift
However, Java EE PaaS is not restricted to these two. I have covered a lot other platforms in my earlier articles. This is done for a more for direct comparison between GAE For Java and Red Hat OpenShift. Please refer to my other articles below on Java EE PaaS.
Java EE PaaS Innovations : Application Server Interoperability
Java EE PaaS : Offerings From IBM And Oracle
Windows Azure Vs VMWare vFabric
Java EE Support:
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Red Hat Open Shift
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Google App Engine for Java
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The JBoss EAP 6.0 cartridge in OpenShift runs in Java EE6 Full Profile. Highlights of the technologies that developers can take advantage of include:
Web application technologies for serving web and mobile content, including Java Servlets, JavaServer Pages (JSP), JavaServer Faces (JSF)
Java Persistence (JPA) for data persistence .
Web services and Java APIs for REST-ful services (JAX-RS) for communicating with mobile devices, HTML5 sites, and external systems.
Enterprise JavaBeans (EJB 3.1), Java Message Service (JMS), and Java Transaction API (JTA)
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With App Engine, you can build web applications using standard Java technologies and run them on Google's scalable infrastructure.
The Java environment provides a Java 6 JVM, a Java Servlets interface, and support for standard interfaces to the App Engine scalable datastore and services, such as JDO, JPA, JavaMail, and JCache.
App Engine uses the Java Servlet standard for web applications. You provide your app's servlet classes, JavaServer Pages (JSPs), static files and data files, along with the deployment descriptor (the web.xml file) and other configuration files, in a standard WAR directory structure. App Engine serves requests by invoking servlets according to the deployment descriptor.
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Integration / Back-End Components:
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Red Hat Open Shift
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Google App Engine for Java
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OpenShift supports a wide list of application technologies. Each technology is delivered as a cartridge - a pluggable capability you can add at any time. When you create an application you start with a web platform cartridge and then can add additional capabilities as you choose.
The following back end databases are supported as part of the PaaS Platform.
MongoDB is a scalable, high-performance, open source NoSQL database.
MySQL is a multi-user, multi-threaded SQL database server.
PostgreSQL is an advanced Object-Relational database management system
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App Engine's underlying datastore is based on BigTable, not a traditional SQL-based RDBMS like MySQL or PostgreSQL. You may either use the low-level datastore API or the JDO or JPA object-relational mapping interfaces provided. Various JDBC wrappers are available for the datastore, and you may still be able to connect to in-memory databases such as the H2 database engine or HSQLDB. SQL. In particular, the following are not Supported: Join operations,
Inequality filtering on multiple properties,
Filtering of data based on results of a sub query.
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Framework Support:
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Red Hat Open Shift
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Google App Engine for Java
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Seam is a framework for developing rich internet Java applications. "Seam integrates technologies such as Asynchronous JavaScript and XML (AJAX), JavaServer Faces (JSF), Java Persistence (JPA), Enterprise Java Beans (EJB 3.0) and Business Process Management (BPM) into a unified full-stack solution.
OpenShift supports it out of the box without any tooling.
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In order to get Seam working on GAE, some workarounds are necessary, as per the documentation available.
Please refer to the article by David Blado PaaS Evangelist for more details on this aspect.
Which PaaS Is Right For My Java App.
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Cloud Attributes (Auto Scaling , Dynamic Infrastructure) :
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Red Hat Open Shift
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Google App Engine for Java
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Application scaling enables your application to react to changes in traffic and automatically allocate the necessary resources to handle your current demand. The OpenShift infrastructure monitors incoming web traffic and automatically brings copies of your web cartridge online to handle requests.
The algorithm for scaling up and scaling down is based on the number of concurrent requests to your application. OpenShift allocates 10 connections per gear - if HAProxy sees that you're sustaining 90% of your peak capacity, it adds another gear. If your demand falls to 50% of your peak capacity for several minutes, HAProxy removes that gear. Simple!
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Automatic scaling is built in with App Engine, all you have to do is write your application code and GAE will do the rest. No matter how many users you have or how much data your application stores, App Engine can scale to meet your needs.
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Summary
The concept of PaaS tends to bring new benefits to the enterprise in terms of managing their core business logic and not concentrate much on the framework and other platform components. On top of it, PaaS is built on Cloud IaaS and comes with it, all the basic benefits of Cloud. In this context both GAE and Open Shift are useful options to evaluate for the enterprises.
However due to the support for Java EE full implementation and open standards along with extended support for common relational databases, Redhat Open Shift provides a better option for porting existing Java EE applications to Cloud.
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