How to upgrade an application to a new version ?
When an application is running on Bluemix and you need to upgrade the version (i.e. going from version 1 to 2) how is this achieved in Bluemix ? In a traditional setup you would have a load balancer routing all the traffic to one data centre while the other data centre version was upgraded and then switch them and upgrade the first one.
Will the "Track & Plan" Add-On in Bluemix help with the above question ?
You will want to employ something along the lines of the blue-green deployment technique as described here.
The 'Track & Plan' and 'Delivery Pipeline' Add-On's can help you with this technique. The blog post here also provides a link to a sample script and the Bluemix documentation here on how to achieve this type of deployment using Bluemix/DevOps.