"Public clouds are great. They offer great elasticity and cost savings, and in the case of a PaaS like Bluemix, allows us (developers) to forget about maintaining any infrastructure and focus in on our code. However we all realize that public cloud can’t be used for everything. There are some applications and services that must remain in our own data centers on private networks. The reasons why vary, maybe it is too much work to move the resource to the cloud, or maybe the data in the resource is too sensitive to risk exposing outside of your firewall. Whatever the reason may be, you are bound to come across a scenario where you need to access private resources in your public cloud applications. What are your options? One option is to try to setup some type of VPN and create a secure connection between the public cloud and your private network. This is probably the route to take if you are using an IaaS provider like SoftLayer to run your application. With a PaaS this is not possible, you don’t have access to the machine your application is running on or the network it is using, so if you choose Bluemix to deploy your application what are your options?
Luckily Bluemix has a solution for this problem and it is called Cloud Integration."http://java.dzone.com/articles/deploying-your-hybrid-cloud?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+javalobby%2Ffrontpage+%28Javalobby+%2F+Java+Zone%29