What's the meaning of orchestration soa -Plain English-

I'm confused about the meaning of Orchestration in SOA, I've read so many definitions but didn't get the idea, c开发者_StackOverflow中文版an you help me?

There are 2 main ways of approaching how to perform all of your necessary fine-grained services from a larger course-grained service, orchestration and choreography.

For orchestration think of a large orchestra. You have a conductor who is controlling the individual orchestra members and/or sections.

For choreography think of a choreographed dance. The dance team coordinates with each other to make sure that they are doing the right thing (no centralized control).

For SOA it works similar. For orchestration you have something that controls the individual sub-tasks (services). For choreography the individual subtasks (services) do their processing then kick-off the next task(s).

In SOA, everything is offered as a service. A service may be atomic or composed of other services. The latter is called "orchestration".

For instance, BPEL is a language to orchestrate services into a new service.

I believe it just refers to using many different services in one application, thus making the application a service oriented architecture. Most, if not all, of the functionality should occur outside the application, making it just the head of a hydra doing lots of work.

Orchestration in SOA is mainly calling services in more than one way. Suppose we have two services one is "Security" service which checks the authenticity of user logged in on the portal and another is "Place Order" service through which we will place an order. we can place order using these services in two way. First we check the authenticity of user through security service then will place order with help of place order service and vice versa. In other words we can say we should be able to define workflow using services.

Orchestration means automated arrangement ,management and coordination of service. Orchestration comes in the context of SOA. Orchestration provides centralized management of resources.