livelessons-cloud-session

Lesson 3: Reaching For The Clouds (Spring Session)

Introduction

This example shows how you can use Redis as backing store for HTTP session data. Unlike the standard session, Redis is a service which remains up even if your application is restarted.

Prerequisites

You will need a Cloud Foundry account and the cf command line tool installed. You will also need a Redis service named ll-cloud-session:

$ cf create-service rediscloud 25mb ll-cloud-session

Testing without Redis

Before showing session data stored in Redis it is helpful to understand how regular session data works. To do this you can modify the application by commenting out the @EnableRedisHttpSession annotation in CloudSessionApplication. You can then try the following:

$ mvn clean package
$ cf push ll-cloud-session -p target/livelessons-cloud-session-1.0.0-SNAPSHOT.jar

Open a browser to the application and refresh it a few times. You should see the same UID displayed. Now lets retart the application (keep the browser open):

cf stop ll-cloud-session
cf start ll-cloud-session

If you now refresh the browser again you should see that a new UID is generated. The old session has gone.

Testing with Redis

To test with a Redis session restore the @EnableRedisHttpSession the rebuild an push the application:

$ mvn clean package
$ cf push ll-cloud-session -p target/livelessons-cloud-session-1.0.0-SNAPSHOT.jar

Repeat the steps above to view the UID in a browser. This time when you restart the application the session should remain and the same UID will always be displayed.