Hi yarn-devs, I am trying to utilize YARN’s host-affinity feature in Apache Samza (SAMZA-617).
I have a question regarding the order in which the resource requests are executed by the RM. Today, we make successive requests for x (say x = 3) containers for deploying a Samza job. It looks like: Request 1: (container-0, $hostX) Request 2: (container-1, $hostY) Request 3: (container-2, $hostZ) When implementing the callback “onContainerAllocated” in the SamzaAppMaster, how can I associate an allocated container with its corresponding containerRequest? Is there a way in YARN to associate an allocated container to its request? If not, is it correct to assume that the RM handles the requests in a FIFO manner and hence, the order in which the onContainerAllocated callback is invoked will be the same as the request order? This information will be very useful for Samza to implement host-affinity in its deployment model. Please let me know. Thanks! Navina
