HADOOP-18227. Add input stream IOStats for vectored IO api in S3A. (apache#4636)

part of HADOOP-18103.

Contributed By: Mukund Thakur

Author: mukund-thakur

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

@@ -47,7 +47,7 @@ public final class StreamStatisticNames {
   public static final String STREAM_READ_ABORTED = "stream_aborted";
 
   /**
-   * Bytes read from an input stream in read() calls.
+   * Bytes read from an input stream in read()/readVectored() calls.
    * Does not include bytes read and then discarded in seek/close etc.
    * These are the bytes returned to the caller.
    * Value: {@value}.
@@ -110,6 +110,34 @@ public final class StreamStatisticNames {
   public static final String STREAM_READ_OPERATIONS =
       "stream_read_operations";
 
+  /**
+   * Count of readVectored() operations in an input stream.
+   * Value: {@value}.
+   */
+  public static final String STREAM_READ_VECTORED_OPERATIONS =
+          "stream_read_vectored_operations";
+
+  /**
+   * Count of bytes discarded during readVectored() operation
+   * in an input stream.
+   * Value: {@value}.
+   */
+  public static final String STREAM_READ_VECTORED_READ_BYTES_DISCARDED =
+          "stream_read_vectored_read_bytes_discarded";
+
+  /**
+   * Count of incoming file ranges during readVectored() operation.
+   * Value: {@value}
+   */
+  public static final String STREAM_READ_VECTORED_INCOMING_RANGES =
+          "stream_read_vectored_incoming_ranges";
+  /**
+   * Count of combined file ranges during readVectored() operation.
+   * Value: {@value}
+   */
+  public static final String STREAM_READ_VECTORED_COMBINED_RANGES =
+          "stream_read_vectored_combined_ranges";
+
   /**
    * Count of incomplete read() operations in an input stream,
    * that is, when the bytes returned were less than that requested.

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/contract/AbstractContractVectoredReadTest.java

@@ -84,6 +84,10 @@ public IntFunction<ByteBuffer> getAllocate() {
     return allocate;
   }
 
+  public WeakReferencedElasticByteBufferPool getPool() {
+    return pool;
+  }
+
   @Override
   public void setup() throws Exception {
     super.setup();
@@ -382,6 +386,13 @@ protected List<FileRange> getSampleOverlappingRanges() {
     return fileRanges;
   }
 
+  protected List<FileRange> getConsecutiveRanges() {
+    List<FileRange> fileRanges = new ArrayList<>();
+    fileRanges.add(FileRange.createFileRange(100, 500));
+    fileRanges.add(FileRange.createFileRange(600, 500));
+    return fileRanges;
+  }
+
   /**
    * Validate that exceptions must be thrown during a vectored
    * read operation with specific input ranges.

hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/S3AInputStream.java

@@ -963,7 +963,6 @@ public int maxReadSizeForVectorReads() {
   @Override
   public void readVectored(List<? extends FileRange> ranges,
                            IntFunction<ByteBuffer> allocate) throws IOException {
-
     LOG.debug("Starting vectored read on path {} for ranges {} ", pathStr, ranges);
     checkNotClosed();
     if (stopVectoredIOOperations.getAndSet(false)) {
@@ -978,6 +977,7 @@ public void readVectored(List<? extends FileRange> ranges,
 
     if (isOrderedDisjoint(sortedRanges, 1, minSeekForVectorReads())) {
       LOG.debug("Not merging the ranges as they are disjoint");
+      streamStatistics.readVectoredOperationStarted(sortedRanges.size(), sortedRanges.size());
       for (FileRange range: sortedRanges) {
         ByteBuffer buffer = allocate.apply(range.getLength());
         unboundedThreadPool.submit(() -> readSingleRange(range, buffer));
@@ -987,6 +987,7 @@ public void readVectored(List<? extends FileRange> ranges,
       List<CombinedFileRange> combinedFileRanges = mergeSortedRanges(sortedRanges,
               1, minSeekForVectorReads(),
               maxReadSizeForVectorReads());
+      streamStatistics.readVectoredOperationStarted(sortedRanges.size(), combinedFileRanges.size());
       LOG.debug("Number of original ranges size {} , Number of combined ranges {} ",
               ranges.size(), combinedFileRanges.size());
       for (CombinedFileRange combinedFileRange: combinedFileRanges) {
@@ -1088,6 +1089,7 @@ private void drainUnnecessaryData(S3ObjectInputStream objectContent, long drainQ
       }
       drainBytes += readCount;
     }
+    streamStatistics.readVectoredBytesDiscarded(drainBytes);
     LOG.debug("{} bytes drained from stream ", drainBytes);
   }
 
@@ -1168,6 +1170,8 @@ private void populateBuffer(int length,
     } else {
       readByteArray(objectContent, buffer.array(), 0, length);
     }
+    // update io stats.
+    incrementBytesRead(length);
   }
 
   /**

hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/S3AInstrumentation.java

@@ -803,6 +803,10 @@ private final class InputStreamStatistics
     private final AtomicLong readOperations;
     private final AtomicLong readFullyOperations;
     private final AtomicLong seekOperations;
+    private final AtomicLong readVectoredOperations;
+    private final AtomicLong bytesDiscardedInVectoredIO;
+    private final AtomicLong readVectoredIncomingRanges;
+    private final AtomicLong readVectoredCombinedRanges;
 
     /** Bytes read by the application and any when draining streams . */
     private final AtomicLong totalBytesRead;
@@ -836,6 +840,10 @@ private InputStreamStatistics(
               StreamStatisticNames.STREAM_READ_SEEK_BYTES_SKIPPED,
               StreamStatisticNames.STREAM_READ_TOTAL_BYTES,
               StreamStatisticNames.STREAM_READ_UNBUFFERED,
+              StreamStatisticNames.STREAM_READ_VECTORED_COMBINED_RANGES,
+              StreamStatisticNames.STREAM_READ_VECTORED_INCOMING_RANGES,
+              StreamStatisticNames.STREAM_READ_VECTORED_OPERATIONS,
+              StreamStatisticNames.STREAM_READ_VECTORED_READ_BYTES_DISCARDED,
               StreamStatisticNames.STREAM_READ_VERSION_MISMATCHES)
           .withGauges(STREAM_READ_GAUGE_INPUT_POLICY)
           .withDurationTracking(ACTION_HTTP_GET_REQUEST,
@@ -872,6 +880,14 @@ private InputStreamStatistics(
           StreamStatisticNames.STREAM_READ_OPERATIONS_INCOMPLETE);
       readOperations = st.getCounterReference(
           StreamStatisticNames.STREAM_READ_OPERATIONS);
+      readVectoredOperations = st.getCounterReference(
+          StreamStatisticNames.STREAM_READ_VECTORED_OPERATIONS);
+      bytesDiscardedInVectoredIO =  st.getCounterReference(
+              StreamStatisticNames.STREAM_READ_VECTORED_READ_BYTES_DISCARDED);
+      readVectoredIncomingRanges = st.getCounterReference(
+              StreamStatisticNames.STREAM_READ_VECTORED_INCOMING_RANGES);
+      readVectoredCombinedRanges = st.getCounterReference(
+              StreamStatisticNames.STREAM_READ_VECTORED_COMBINED_RANGES);
       readFullyOperations = st.getCounterReference(
           StreamStatisticNames.STREAM_READ_FULLY_OPERATIONS);
       seekOperations = st.getCounterReference(
@@ -1017,6 +1033,19 @@ public void readOperationCompleted(int requested, int actual) {
       }
     }
 
+    @Override
+    public void readVectoredOperationStarted(int numIncomingRanges,
+                                             int numCombinedRanges) {
+      readVectoredIncomingRanges.addAndGet(numIncomingRanges);
+      readVectoredCombinedRanges.addAndGet(numCombinedRanges);
+      readVectoredOperations.incrementAndGet();
+    }
+
+    @Override
+    public void readVectoredBytesDiscarded(int discarded) {
+      bytesDiscardedInVectoredIO.addAndGet(discarded);
+    }
+
     /**
      * {@code close()} merges the stream statistics into the filesystem's
      * instrumentation instance.

hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/statistics/S3AInputStreamStatistics.java

@@ -96,6 +96,20 @@ void streamClose(boolean abortedConnection,
    */
   void readOperationCompleted(int requested, int actual);
 
+  /**
+   * A vectored read operation has started..
+   * @param numIncomingRanges number of input ranges.
+   * @param numCombinedRanges number of combined ranges.
+   */
+  void readVectoredOperationStarted(int numIncomingRanges,
+                                    int numCombinedRanges);
+
+  /**
+   * Number of bytes discarded during vectored read.
+   * @param discarded discarded bytes during vectored read.
+   */
+  void readVectoredBytesDiscarded(int discarded);
+
   @Override
   void close();
 

hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/statistics/impl/EmptyS3AStatisticsContext.java

@@ -195,6 +195,17 @@ public void readOperationCompleted(final int requested, final int actual) {
 
     }
 
+    @Override
+    public void readVectoredOperationStarted(int numIncomingRanges,
+                                             int numCombinedRanges) {
+
+    }
+
+    @Override
+    public void readVectoredBytesDiscarded(int discarded) {
+
+    }
+
     @Override
     public void close() {