I ofter talk about Cisco ACI because that's what I work with for a living. A lot of times we get complaints about how much design needs to be done due to the legacy apps out there. As I was listening to the latest Datanauts podcast, though, I realized something. It's not just Cisco ACI that's trying to drive this application centric model, it's everything out there. It's containers, and microservices, and unikernels...but really it's the microservices. There's a new buzzword called GIFEE, which stands for Google Infrstructure for Everyone Else.
I mean, really, all the large companies are doing things like this--granularly separating all the services to create a complete application. Redundancy is all built in...this is how Netflix's Chaos Monkey can bring things down with hopefully no downtime for the customers. Of course, we're all going to have legacy applications and we'll need to incorporate that into our environments somehow.
I think as long as we're moving towards the application centric model, we'll be in good shape. Start with new applications, or applications you're looking to totally revamp. Use Software Defined Networking, such as Cisco ACI, under that. Integrate hybrid cloud and even CMTs like CliQr or vRealize Automation from VMware. The cool thing with ACI is that you can even integrate bare metal servers. One network to manage all your new apps and all your legacy apps. No matter what, you get all the benefits of automation, reusability, and troubleshooting...and you can take your time getting there.