How to deploy Java App Engine application on another cloud?

I have written a relatively simple Java App Engin开发者_如何转开发e application which I would like to be able to port to another cloud provider.

I am using the JDO datastore API so I think my data handling should be portable to other backends as listed here: http://www.datanucleus.org/products/accessplatform/index.html

I would ideally like to deploy my application onto EC2 with minimal code changes. What is my best approach?

Note: I am aware of the http://code.google.com/p/appscale/ project but I want to avoid using this as it doesn't look like they are updating very often.

AppScale remains your best option to avoid rewriting any code. They do keep up to date with official App Engine - for instance, they just released preliminary support for Go. Even if they weren't so assiduous at keeping up to date, though, this would only be relevant if some feature you required wasn't yet supported - and it sounds like your needs are fairly basic.

JDO should be trivial, there might be some Google specific configuration here and there but generally it should be easy. The storage model Google promotes is not bad for RDBMS either, but you might need to fine tune your model depending on the backend you end up with.

If you're not using the low-level Google APIs, you should be pretty much there.

I managed to get my application working on EC2 using the following components.

• Tomcat 7
• Datanucelus
• HBase

I had to manually create a table in HBase for each of my data classes but was able to configure Datanucleus to auto create the columns.

I also had to change my primary key value generation strategy from identity to increment as per this table of supported features. http://www.datanucleus.org/products/accessplatform_3_0/datastore_features.html