Is Google App Engine suitable for near-realtime event-driven application?

We're going to develop a near-realtime event-driven application (backend and bunch of mobile clients).

I think Akka (http://akka.io) is more than suitable for this. However, my collegaue wants to use Google App Engine and its async f开发者_开发知识库eatures. I'm not convinced it's the best approach to take, I wonder if we can somehow meld those two things together. I can't find any solid contemporary info via Google.

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The Channel API may be useful. However, the main limitation you may face using app engine are transactional writes to the datastore, because an entity group (parent entity and its children) can only support one to ten writes per second.

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It is notable that the new Go support for app engine supports actor-style programming with goroutines. When datastore or other ops block then other goroutines run. It would be nice if someone could do this for scala and one of the actor variants. The new backend system allows this style to be used in a long running way I presume.

Unrelatedly, on the issue of writing to an entity group. I write a record that might be already there (same key_name), and now I'm wondering if I should read it first to check.