Über jars vs thin wars, pros and cons

This post was inspired by a Twitter conversation with Reza Rahman where, as far as it goes on Twitter, the relative merits of using Über jars as opposed to thin wars were being bandied about. My first post on my new blog is also quite a long one, please bear with me. A little history There is a growing tendency in the industry to move away from the traditional monolithic application run on a fully tooled up application server towards running apps defined by the single service they provide, the so called microservice. Here the emphasis is reducing the application to providing independent support for one thing . The idea behind the microservice is the microservices architecture where a set of loosely coupled microservices are used to build applications using them. 
This has, in turn, driven the development of application servers better suited to running microservices in them. The industry's response to the demand for microservices support has been the forming of the Micro Profile I…