diff --git a/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/BlockingThreadPoolExecutorService.java b/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/BlockingThreadPoolExecutorService.java
index 404eea9618e..f13942d3822 100644
--- a/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/BlockingThreadPoolExecutorService.java
+++ b/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/BlockingThreadPoolExecutorService.java
@@ -15,7 +15,8 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.apache.hadoop.util;
+
+package org.apache.hadoop.fs.s3a;
 
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.LinkedBlockingQueue;
@@ -41,7 +42,7 @@ import org.apache.hadoop.classification.InterfaceAudience;
  * this s4 threadpool</a>
  */
 @InterfaceAudience.Private
-public final class BlockingThreadPoolExecutorService
+final class BlockingThreadPoolExecutorService
     extends SemaphoredDelegatingExecutor {
 
   private static final Logger LOG = LoggerFactory
@@ -85,7 +86,7 @@ public final class BlockingThreadPoolExecutorService
    * @return a thread factory that creates named, daemon threads with
    * the supplied exception handler and normal priority
    */
-  public static ThreadFactory newDaemonThreadFactory(final String prefix) {
+  static ThreadFactory newDaemonThreadFactory(final String prefix) {
     final ThreadFactory namedFactory = getNamedThreadFactory(prefix);
     return new ThreadFactory() {
       @Override
diff --git a/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/S3AFileSystem.java b/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/S3AFileSystem.java
index e9277586e4b..63a43492b49 100644
--- a/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/S3AFileSystem.java
+++ b/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/S3AFileSystem.java
@@ -112,10 +112,8 @@ import org.apache.hadoop.fs.s3a.s3guard.S3Guard;
 import org.apache.hadoop.fs.s3native.S3xLoginHelper;
 import org.apache.hadoop.io.retry.RetryPolicies;
 import org.apache.hadoop.security.UserGroupInformation;
-import org.apache.hadoop.util.BlockingThreadPoolExecutorService;
 import org.apache.hadoop.util.Progressable;
 import org.apache.hadoop.util.ReflectionUtils;
-import org.apache.hadoop.util.SemaphoredDelegatingExecutor;
 
 import static org.apache.hadoop.fs.s3a.Constants.*;
 import static org.apache.hadoop.fs.s3a.Invoker.*;
diff --git a/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/SemaphoredDelegatingExecutor.java b/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/SemaphoredDelegatingExecutor.java
index bcc19e35e85..6b21912871e 100644
--- a/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/SemaphoredDelegatingExecutor.java
+++ b/hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/SemaphoredDelegatingExecutor.java
@@ -16,7 +16,7 @@
  * limitations under the License.
  */
 
-package org.apache.hadoop.util;
+package org.apache.hadoop.fs.s3a;
 
 import com.google.common.util.concurrent.ForwardingListeningExecutorService;
 import com.google.common.util.concurrent.Futures;
@@ -42,13 +42,17 @@ import java.util.concurrent.TimeoutException;
  * This is a refactoring of {@link BlockingThreadPoolExecutorService}; that code
  * contains the thread pool logic, whereas this isolates the semaphore
  * and submit logic for use with other thread pools and delegation models.
+ * In particular, it <i>permits multiple per stream executors to share a
+ * single per-FS-instance executor; the latter to throttle overall
+ * load from the the FS, the others to limit the amount of load which
+ * a single output stream can generate.</i>
  * <p>
  * This is inspired by <a href="https://github.com/apache/incubator-s4/blob/master/subprojects/s4-comm/src/main/java/org/apache/s4/comm/staging/BlockingThreadPoolExecutorService.java">
  * this s4 threadpool</a>
  */
 @SuppressWarnings("NullableProblems")
 @InterfaceAudience.Private
-public class SemaphoredDelegatingExecutor extends
+class SemaphoredDelegatingExecutor extends
     ForwardingListeningExecutorService {
 
   private final Semaphore queueingPermits;
@@ -61,8 +65,7 @@ public class SemaphoredDelegatingExecutor extends
    * @param permitCount number of permits into the queue permitted
    * @param fair should the semaphore be "fair"
    */
-  public SemaphoredDelegatingExecutor(
-      ListeningExecutorService executorDelegatee,
+  SemaphoredDelegatingExecutor(ListeningExecutorService executorDelegatee,
       int permitCount,
       boolean fair) {
     this.permitCount = permitCount;
@@ -187,7 +190,7 @@ public class SemaphoredDelegatingExecutor extends
 
     private Runnable delegatee;
 
-    RunnableWithPermitRelease(Runnable delegatee) {
+    public RunnableWithPermitRelease(Runnable delegatee) {
       this.delegatee = delegatee;
     }
 
@@ -209,7 +212,7 @@ public class SemaphoredDelegatingExecutor extends
 
     private Callable<T> delegatee;
 
-    CallableWithPermitRelease(Callable<T> delegatee) {
+    public CallableWithPermitRelease(Callable<T> delegatee) {
       this.delegatee = delegatee;
     }
 
diff --git a/hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/ITestBlockingThreadPoolExecutorService.java b/hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/ITestBlockingThreadPoolExecutorService.java
index 3dfe286bc7b..b1b82400ceb 100644
--- a/hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/ITestBlockingThreadPoolExecutorService.java
+++ b/hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/ITestBlockingThreadPoolExecutorService.java
@@ -19,8 +19,6 @@
 package org.apache.hadoop.fs.s3a;
 
 import com.google.common.util.concurrent.ListenableFuture;
-import org.apache.hadoop.util.BlockingThreadPoolExecutorService;
-import org.apache.hadoop.util.SemaphoredDelegatingExecutor;
 import org.apache.hadoop.util.StopWatch;
 
 import org.junit.AfterClass;