HDFS-9261. Erasure Coding: Skip encoding the data cells if all the parity data streamers are failed for the current block group. (Rakesh R via umamahesh)

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DFSStripedOutputStream.java

@@ -844,6 +844,11 @@ private boolean generateParityCellsForLastStripe() {
 
   void writeParityCells() throws IOException {
     final ByteBuffer[] buffers = cellBuffers.getBuffers();
+    // Skips encoding and writing parity cells if there are no healthy parity
+    // data streamers
+    if (!checkAnyParityStreamerIsHealthy()) {
+      return;
+    }
     //encode the data cells
     encode(encoder, numDataBlocks, buffers);
     for (int i = numDataBlocks; i < numAllBlocks; i++) {
@@ -852,6 +857,19 @@ void writeParityCells() throws IOException {
     cellBuffers.clear();
   }
 
+  private boolean checkAnyParityStreamerIsHealthy() {
+    for (int i = numDataBlocks; i < numAllBlocks; i++) {
+      if (streamers.get(i).isHealthy()) {
+        return true;
+      }
+    }
+    if (LOG.isDebugEnabled()) {
+      LOG.debug("Skips encoding and writing parity cells as there are "
+          + "no healthy parity data streamers: " + streamers);
+    }
+    return false;
+  }
+
   void writeParity(int index, ByteBuffer buffer, byte[] checksumBuf)
       throws IOException {
     final StripedDataStreamer current = setCurrentStreamer(index);

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -184,6 +184,9 @@ Trunk (Unreleased)
     HDFS-9070. Allow fsck display pending replica location information for
     being-written blocks. (GAO Rui via jing9)
 
+    HDFS-9261. Erasure Coding: Skip encoding the data cells if all the parity data 
+    streamers are failed for the current block group. (Rakesh R via umamahesh)
+
   OPTIMIZATIONS
 
   BUG FIXES