Esempio n. 1
0
    /**
     * Get a runnable node in the given rack that is not present in the excluded list
     *
     * @param requestedNode the node to look up rack locality for
     * @param excluded the list of nodes to ignore
     * @return the runnable node from the rack satisfying conditions, null if the node was not found
     */
    public ClusterNode getRunnableNodeForRack(RequestedNode requestedNode, Set<String> excluded) {

      NodeContainer nodeContainer = requestedNode.getRackNodes();
      getRunnableNodeForRackCounter += 1;
      if (nodeContainer == null) {
        return null;
      }
      synchronized (nodeContainer) {
        if (nodeContainer.isEmpty()) {
          return null;
        }
        if (getRunnableNodeForRackCounter % RACK_SHUFFLE_PERIOD == 0) {
          // This balances more evenly across nodes in a rack
          nodeContainer.shuffle();
        }
        for (ClusterNode node : nodeContainer) {
          if (excluded == null || !excluded.contains(node.getHost())) {
            if (resourceLimit.hasEnoughResource(node)) {
              return node;
            }
          }
        }
      }
      return null;
    }