I think it would be more accurate to say you could build a basic Zookeeper on top of FoundationDB rather than use it as a replacement. It depends on what level

I think it would be more accurate to say you could build a basic Zookeeper on top of FoundationDB rather than use it as a replacement. It depends on what level you're using Zookeeper at. Because it's fairly trival to slap together a consistent store on top of FundationDB because, well that's what it is. But if you need ephemeral nodes tired to heartbeated sessions and sequentially consistent set of watches to be triggered... Well that's quite a bit harder. I'm less familiar with etcd, but I suspect the devil is in the details.