Thanks Alex. For 1. I understand currently the only choice is C++. However, as Adam mentioned, true pluggable allocator modules (MESOS-2160 <https://issues.apache.org/jira/browse/MESOS-2160>) are landing in Mesos 0.23, so at that time, I assume we will have more choices, right?
For 2 and 3, my understanding is Mesos allocator will partition all the available resources into multiple subsets, and there is no overlap between these subsets (i.e., a single resource can only be in one subset), and then offer these subsets to multiple frameworks (e.g., offer subset1 to framework1, offer subset2 to framework2, and so on), and it is up to each framework's scheduler to determine if it accept the resource to launch task or reject it. In this way, each framework's scheduler can actually make scheduling decision independently since they will never compete for the same resource. If my understanding is correct, then I have one more question: 4. What if it takes very long time (e.g., mins or hours) for a framework's scheduler to make the scheduling decision? Does that mean during this long period, the resources offered to this framework will not be used by any other frameworks? Is there a timeout for the framework's scheduler to make the scheduling decision? So when the timeout is reached, the resources offered to it will be revoked by Mesos allocator and can be offered to another framework.
