That doesn't have anything to do with availability, at least not in the CAP theorem sense as I understand it. What I think you're talking about (being "blown ou

That doesn't have anything to do with availability, at least not in the CAP theorem sense as I understand it. What I think you're talking about (being "blown out of the water" is pretty vague, though) is partition tolerance: high-latency requests that are practically indistinguishable from network partition events. I'm not sure what MongoDB returns (or how its clients react) when there are no available connections because of a lock whose duration exceeds the configured timeout. I'm pretty confident, though, that this sort of thing is covered by basic driver config.