May 6, 2016 | Written by: Bobby Woolf
Categorized: Community | Compute Services
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We’ve reviewed how WebSphere Liberty differs from older Java EE application server products, which makes it better suited for cloud applications and microservices. Is it the same as WebSphere Application Server (WAS)? And what are the different options for creating a Liberty runtime?
In this excerpt from “Java EE, the next inception: A primer to WebSphere Liberty for Java EE developers,” we’ll explore how Liberty compares to traditional WAS. Next, we’ll look at the difference between a profile and a server.
To start at the beginning of this series, see WebSphere Liberty: Developing Java EE applications for the cloud.
Difference between Liberty and WebSphere Application Server
WebSphere Application Server is made up of two application server runtime environments called profiles:
- Traditional WAS (sometimes referred to as WebSphere Application Server “classic” or “full profile”) – The original architecture of WebSphere Application Server that started in 1998 with Servlet Express v1.0 and evolved into an industrial-strength Java EE container.
- Liberty (sometimes called “WAS Liberty” or “Liberty profile”) – The next generation Java EE container architecture, introduced in WebSphere Application Server v8.5.0 in 2013, designed to be highly composable, to start faster, use less memory, and scale better.
Which WebSphere Application Server are you familiar with? When you’re using a WebSphere Application Server Network Deployment cell, each cluster member runs in an installation of traditional WAS. Even though Liberty is part of the WebSphere Application Server product, you may not have used it yet.
As you’ll see, Liberty’s runtime is very compact and lightweight, making it particularly well-suited for virtualized infrastructure and cloud computing, for lightweight containers, and also for devices in the Internet of Things.
Liberty is available packaged in several different platforms. As of this writing, they are:
- Liberty profile – Part of WebSphere Application Server and available separately, for installation on an on-premise computer, including installing it locally on your laptop for development.
- Liberty Docker images – The
websphere-liberty images that run Liberty in Docker containers.
- Bluemix instant runtime – The Liberty for Java runtime in Bluemix, built using the IBM WebSphere Application Server Liberty Buildpack for Cloud Foundry.
- Bluemix container – The IBM Liberty Image (
ibmliberty), the websphere-liberty image optimized for running in Bluemix.
For a given version of Liberty (such as v184.108.40.206), each of these installs provides equivalent, nearly identical functionality. The main difference is that the buildpack does not include Liberty features that are not used in a cloud environment.
—Bobby Woolf (@bobby_woolf)