Need to understand the concepts in wf like sequences, variables, etc to learn to think in terms of workflow when designing applications.
Basically this session I about applying wf for a messaging app (wcf).
Use wf to replace coordination code.
Coordination code gets excessive in async code.
Wf rumtime has far better performance.
Get true parallelism in 4.0.
Looks like a very nor relationship between wcf and wf. Basically the architecture is to UAE messages received kick off wf which has all the plumbing for fast performance such as parallelism.
We could use wf 4.0 to execute parallel calls to the database to get the data or objects for a view.
Workflow in client will automate the continuation of execution even while the service is shut down and restarted.
He did a demo where he launched a client. Issued a request while the server was shut down, shut down the app, started the service, started the client and then the request was completed.
Uses the concept of peraiatence (a workflow state store) and correllation (mapping between request and responses and workflow).
I think these two concepts are new to 4.0.
Demo of tracking services in wf.
Express services as workflows and get tracking for free.
When should you use wf with wcf?
If your app does:
Calls a db, calls service.
Coord parallel work.
Enforces ordering.
Coordinates messages.
Has a long running flow.
Needs persistence.
We should prototype this for paralleling the calls for objects to load a view.
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