How orchestration differs from automation in the enterprise cloud.
The orchestration of workflow processes is an essential part of cloud computing. Without orchestration, many of the benefits and characteristics of cloud computing cannot be achieved at the price point that cloud services should be offered. Failure to automate as many processes as possible results in higher personnel labor costs, slower time to deliver the new service to customers, and ultimately higher cost with less reliability.
What is meant by automation? Automation is technique used in traditional data centers —and critical in a cloud environment — to install software or initiate other activities. Traditional IT administrators use sequential scripts to perform a series of tasks (e.g. software installation or configuration); however, this is now considered an antiquated technique in a modern cloud-based environment. Orchestration differs from automation in that it does not rely entirely on static sequential scripts but rather sophisticated workflows; multiple automated threads; query-based and if/then logic; object-oriented and topology workflows; and even the ability to back-out a series of automated commands if necessary.
Orchestration can best be explained through a typical use case example of a customer placing an order within their cloud service web-portal, and following the steps necessary to bring the service online. The actions below illustrate a very high level scenario where the cloud management software performs the orchestration:
Start exploring Kubernetes with minimal effort.
I had not looked at Kubernetes in over a month. It is a fast paced project so it is hard to keep up. If you have not looked at Kubernetes, it is roughly a cluster manager for containers. It takes a set of Docker hosts under management and schedules groups of containers in them. Kubernetes was open sourced by Google around June last year to bring all the Google knowledge of working with containers to us, a.k.a The people :) There are a lot of container schedulers or orchestrators if you wish out there, Citadel, Docker Swarm, Mesos with the Marathon framework, Cloud Foundry lattice etc. The Docker ecosystem is booming and our heads are spinning.
What I find very interesting with Kubernetes is the concept of replication controllers. Not only can you schedule groups of colocated containers together in a cluster, but you can also define replica sets. Say you have a container you want to scale up or down, you can define a replica controller and use it to resize the number of containers running. It is great for scaling when the load dictates it, but it is also great when you want to replace a container with a new image. Kubernetes also exposes a concept of services basically a way to expose a container application to all the hosts in your cluster as if it were running locally. Think the ambassador pattern of the early Docker days but on steroids.