MAPREDUCE-7435. Mehakmeet review

Change-Id: Ica813c6068eca18d83bf2f5f94fac4a1e1996c36

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/statistics/IOStatisticsSetters.java

@@ -29,7 +29,7 @@
  * {@link IOStatisticsSnapshot} to also support it.
  * These are the simple setters, they don't provide for increments,
  * decrements, calculation of min/max/mean etc.
- * @since The interface and IOStatisticsSnapshot support was added after Hadoop 3.3.5
+ * @since The interface and IOStatisticsSnapshot support was added <i>after</i> Hadoop 3.3.5
  */
 @InterfaceAudience.Public
 @InterfaceStability.Evolving

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/statistics/TestIOStatisticsSetters.java

@@ -21,6 +21,7 @@
 import java.util.Arrays;
 import java.util.Collection;
 
+import org.assertj.core.api.Assertions;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.Parameterized;
@@ -61,12 +62,14 @@ public class TestIOStatisticsSetters extends AbstractHadoopTestBase {
 
   private final IOStatisticsSetters ioStatistics;
 
-  @Parameterized.Parameters
+  private final boolean createsNewEntries;
+
+  @Parameterized.Parameters(name="{0}")
   public static Collection<Object[]> params() {
     return Arrays.asList(new Object[][]{
-        {new IOStatisticsSnapshot()},
-        {createTestStore()},
-        {new ForwardingIOStatisticsStore(createTestStore())},
+        {"IOStatisticsSnapshot", new IOStatisticsSnapshot(), true},
+        {"IOStatisticsStore", createTestStore(), false},
+        {"ForwardingIOStatisticsStore", new ForwardingIOStatisticsStore(createTestStore()), false},
     });
   }
 
@@ -84,8 +87,13 @@ private static IOStatisticsStore createTestStore() {
         .build();
   }
 
-  public TestIOStatisticsSetters(IOStatisticsSetters ioStatisticsSetters) {
+  public TestIOStatisticsSetters(
+      String source,
+      IOStatisticsSetters ioStatisticsSetters,
+      boolean createsNewEntries) {
     this.ioStatistics = ioStatisticsSetters;
+
+    this.createsNewEntries = createsNewEntries;
   }
 
   @Test
@@ -101,7 +109,16 @@ public void testCounter() throws Throwable {
         .isEqualTo(2);
 
     // unknown value
-    ioStatistics.setCounter("c2", 3);
+    final String unknown = "unknown";
+    ioStatistics.setCounter(unknown, 3);
+    if (createsNewEntries) {
+      assertThatStatisticCounter(ioStatistics, unknown)
+          .isEqualTo(3);
+    } else {
+      Assertions.assertThat(ioStatistics.counters())
+          .describedAs("Counter map in {}", ioStatistics)
+          .doesNotContainKey(unknown);
+    }
   }
 
   @Test

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/lib/output/committer/manifest/impl/InternalConstants.java

@@ -127,5 +127,4 @@ private InternalConstants() {
   /** Schemas of filesystems we know to not work with this committer. */
   public static final Set<String> UNSUPPORTED_FS_SCHEMAS =
       ImmutableSet.of("s3a", "wasb");
-
 }

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/test/java/org/apache/hadoop/mapreduce/lib/output/committer/manifest/TestJobThroughManifestCommitter.java

@@ -146,6 +146,8 @@ public class TestJobThroughManifestCommitter
 
   /**
    * Loaded manifest data, set in job commit and used in validation.
+   * This is static so it can be passed from where it is loaded
+   * {@link #test_0400_loadManifests()} to subsequent tests.
    */
   private static LoadedManifestData
       loadedManifestData;

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/test/java/org/apache/hadoop/mapreduce/lib/output/committer/manifest/TestRenameStageFailure.java

@@ -86,6 +86,9 @@ public class TestRenameStageFailure extends AbstractManifestCommitterTest {
   /** resilient commit expected? */
   private boolean resilientCommit;
 
+  /**
+   * Entry file IO.
+   */
   private EntryFileIO entryFileIO;
 
   protected boolean isResilientCommit() {

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/test/java/org/apache/hadoop/mapreduce/lib/output/committer/manifest/impl/TestEntryFileIO.java

@@ -193,6 +193,7 @@ public void testCreateEmptyFile() throws Throwable {
     // now use the iterator to access it.
     List<FileEntry> files = new ArrayList<>();
     Assertions.assertThat(foreach(iterateOverEntryFile(), files::add))
+        .describedAs("Count of iterations over entries in an entry file with no entries")
         .isEqualTo(0);
   }