What is a good WCF SOA strategy?

I'开发者_如何学编程ve worked on enterprise level SOA applications that have a whole lot of very simple one-off WCF services.

The code for some of these services could easily be placed into one central service and accessed through different method calls.

What are the advantages or disadvantages of having many of these one-off services?

As you have recognised there is a tension between decomposing services into small, reusable, separately deployed building blocks and manageability of large numbers of services

Separate services

For: Flexibility of deployment, reuse and composition

Against: Manageability, overhead of invocation if the services needs to talk to eachother

One big service

For: Simplified deployment and management, in-memory invocation between "services"

Against: Reuse reuses entire service, added contention for unrelated functionality, potential scalability problems

As with most of these questions the best solutions comes somewhere in the middle - grouping similar services into single deployments while retaining the flexibility to scale out some groups of services with heavier usage