Reading Time: 2 minutes While porting an application to Google App Engine we encountered several issues. Most of them where related to persistence. We were using JPA for persistence in the application. One of the most common mistake we did was in issuing a JPA Query where one or more parameters are of type com.google.appengine.datastore.api.Key class. Key class has two String representations which lead to some confusion. Let’s look Continue Reading
Reading Time: 3 minutes One of the most frequently talked barriers for getting onto the cloud is the data lock-in. In this post we would try to look at how we can download data as a CSV from the app engine datastore. This would help us get the data back from the app engine, just in case you want to move away from the datastore. So there exists a Continue Reading
Reading Time: 2 minutes As you would have read in our previous post, we used the Namespace API to make the SaaS application that we were working on multi-tenant in a matter of four hours. You would have noticed that we set the tenant name in the NamespaceManager [sourcecode language=”java”] NamespaceManager.set(request.getServerName()); [/sourcecode] Our initial assumption was that the NamespaceManager would continue to exist for the lifetime of the session Continue Reading
Reading Time: 4 minutes By definition, lock-in makes a customer dependent on a vendor for products and services, unable to use another vendor without substantial switching costs. That sounds scary. Now let us take a step back and look at all the standards which were available in the traditional world to prevent lock-in. JEE specs sure have a lot of them and that ensures that you would be able Continue Reading
Reading Time: 3 minutes Google Dev and production environment has differences. You may run into problems if you expect that application will also run fine on app engine if there are no errors on app engine development server. We are in process of porting an existing application on Google App engine. The application we are building uses Wicket, Spring and JPA. If you read the will it play in Continue Reading
Reading Time: 5 minutes Performance Tuning is one of the stages of taking your application to production which you can seldom avoid. Irrespective of the fact whether you have taken all good performance practices into account, there is something or the other which needs to be tuned before the application is production ready. Performance Tuning takes a different turn when your application is supposed to run on the cloud. Continue Reading
Reading Time: 2 minutes Sometimes it is handy to debug our application source code even when it is executing outside our IDE. This blog will explain how can we remotely debug a web application project developed in Google App Engine on eclipse IDE. The linux command to start web application on Google App engine development application server is [sourcecode language=”bash”] dev_appserver.sh <exploded WAR directory path> [/sourcecode] The command runs Continue Reading
