YARN-8896. Limit the maximum number of container assignments per heartbeat. (Zhankun Tang via wangda)

Change-Id: I6e72f8362bd7f5c2a844cb9e3c4732492314e9f1

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/capacity/CapacitySchedulerConfiguration.java

@@ -336,8 +336,11 @@ public class CapacitySchedulerConfiguration extends ReservationSchedulerConfigur
   public static final String MAX_ASSIGN_PER_HEARTBEAT = PREFIX
       + "per-node-heartbeat.maximum-container-assignments";
 
+  /**
+   * Avoid potential risk that greedy assign multiple may involve
+   * */
   @Private
-  public static final int DEFAULT_MAX_ASSIGN_PER_HEARTBEAT = -1;
+  public static final int DEFAULT_MAX_ASSIGN_PER_HEARTBEAT = 100;
 
   /** Configuring absolute min/max resources in a queue. **/
   @Private