diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/SchedulingPolicy.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/SchedulingPolicy.java
index 9a9be8c10c3..c91bc5c85f8 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/SchedulingPolicy.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/scheduler/fair/SchedulingPolicy.java
@@ -33,6 +33,11 @@
import java.util.Comparator;
import java.util.concurrent.ConcurrentHashMap;
+/**
+ * The scheduling policy for a queue.
+ * It determines the strategy to share resources between the
+ * running applications within this queue.
+ */
@Public
@Evolving
public abstract class SchedulingPolicy {
@@ -41,11 +46,16 @@
public static final SchedulingPolicy DEFAULT_POLICY =
getInstance(FairSharePolicy.class);
-
+
/**
- * Returns a {@link SchedulingPolicy} instance corresponding to the passed clazz
+ * Returns a {@link SchedulingPolicy} instance corresponding
+ * to the passed clazz.
+ *
+ * @param clazz a class that extends {@link SchedulingPolicy}
+ * @return a {@link SchedulingPolicy} instance
*/
- public static SchedulingPolicy getInstance(Class extends SchedulingPolicy> clazz) {
+ public static SchedulingPolicy getInstance(
+ Class extends SchedulingPolicy> clazz) {
SchedulingPolicy policy = ReflectionUtils.newInstance(clazz, null);
SchedulingPolicy policyRet = instances.putIfAbsent(clazz, policy);
if(policyRet != null) {
@@ -63,7 +73,9 @@ public static SchedulingPolicy getInstance(Class extends SchedulingPolicy> cla
* canonical class name of the {@link SchedulingPolicy}.
*
* @param policy canonical class name or "drf" or "fair" or "fifo"
+ * @return a {@link SchedulingPolicy} instance parsed from given policy
* @throws AllocationConfigurationException
+ *
*/
@SuppressWarnings("unchecked")
public static SchedulingPolicy parse(String policy)
@@ -94,7 +106,7 @@ public static SchedulingPolicy parse(String policy)
/**
* Initialize the scheduling policy with cluster resources.
- * @deprecated Since it doesn't track cluster resource changes, replaced by
+ * @deprecated Since it doesn't track cluster resource changes, replaced by
* {@link #initialize(FSContext)}.
*
* @param clusterCapacity cluster resources
@@ -158,7 +170,7 @@ public abstract void computeSteadyShares(
Collection extends FSQueue> queues, Resource totalResources);
/**
- * Check if the resource usage is over the fair share under this policy
+ * Check if the resource usage is over the fair share under this policy.
*
* @param usage {@link Resource} the resource usage
* @param fairShare {@link Resource} the fair share
@@ -168,10 +180,10 @@ public abstract boolean checkIfUsageOverFairShare(
Resource usage, Resource fairShare);
/**
- * Get headroom by calculating the min of clusterAvailable and
- * (queueFairShare - queueUsage) resources that are
+ * Get headroom by calculating the min of {@code clusterAvailable} and
+ * ({@code queueFairShare} - {@code queueUsage}) resources that are
* applicable to this policy. For eg if only memory then leave other
- * resources such as CPU to same as clusterAvailable.
+ * resources such as CPU to same as {@code clusterAvailable}.
*
* @param queueFairShare fairshare in the queue
* @param queueUsage resources used in the queue