blockId0Parts.length != 4

Author: jinxing

common/network-shuffle/src/main/java/org/apache/spark/network/shuffle/ExternalShuffleBlockHandler.java

@@ -203,14 +203,14 @@ private class ManagedBufferIterator implements Iterator<ManagedBuffer> {
       this.appId = appId;
       this.execId = execId;
       String[] blockId0Parts = blockIds[0].split("_");
-      if (blockId0Parts.length < 4 || !blockId0Parts[0].equals("shuffle")) {
+      if (blockId0Parts.length != 4 || !blockId0Parts[0].equals("shuffle")) {
         throw new IllegalArgumentException("Unexpected shuffle block id format: " + blockIds[0]);
       }
       this.shuffleId = Integer.parseInt(blockId0Parts[1]);
       mapIdAndReduceIds = new int[2 * blockIds.length];
       for (int i = 0; i < blockIds.length; i++) {
         String[] blockIdParts = blockIds[i].split("_");
-        if (blockIdParts.length < 4 || !blockIdParts[0].equals("shuffle")) {
+        if (blockIdParts.length != 4 || !blockIdParts[0].equals("shuffle")) {
           throw new IllegalArgumentException("Unexpected shuffle block id format: " + blockIds[i]);
         }
         if (Integer.parseInt(blockIdParts[1]) != shuffleId) {