I recently worked on a long running migration project, where we needed to ensure that some of the sql migration scripts were only called once per entity that was migrated, in a threadsafe manner. I looked to the System.Collections.Concurrent namespace, but none of the classes were really a good match. Basically what I needed was the ability to run a part of the migration that was identified by key, but ensure that it would only run once, although different parent strategies might try and run it.

Pleanty of people have said that concurrency and functional programming are becomming essential to developing modern systems. Some have even gone so far as to say that if you don't adapt you will become a maintenance programmer in a few years. With the increasing need for concurrency to provide speed and handeling of huge amounts of data, I beleive it to be true. I do however beleive there will still be pleanty of smaller applications, so I am not predicting doomesday for anyone quite yet.

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