WCF cluster for mid-length tasks

Question

We have a self-hosted WCF application which analyses text. The installation we're discussing, involves processing batches of small fragments of text (social media) and longer ones (like newspaper articles). The longer fragments take on average 5-6 sec to process in one WCF instance, while the shorter ones are under 1 sec. There are millions of items of each kind to be processed every day.

Several questions:

1. What is the recommended configuration? Windows Azure / any kind of IaaS like Amazon / cluster managed by a load balancer?
2. Is there a built-in support for load balancing in WCF, which does not require writing a wrapper?
3. For some reason, when a long task is running and another task is submitted to an instance deployed on a multicore machine, they both run in parallel on the same core, instead of starting on another core which is free. Is this some kind of conservative allocation? Can it be managed more efficiently?

Answer 1

1. The easy answer is Azure (because it's a PaaS by microsoft) but it isn't really a technical question. It depends on costs, and growth prediction.
2. Not really. WCF supports load balancing, but WCF itself runs in your process and can't load balance itself. It's usually a feature of your hosting platform.
3. If that's 2 different processes then the OS schedules CPU-time, and I wouldn't recommend messing with that. If both were run on the same core it's probably because they can (which makes sense, as WCF uses a lot if IO)