Revert "HDFS-14557. JournalNode error: Can't scan a pre-transactional edit log. Contributed by Stephen O'Donnell."

This reverts commit 45ba41570b02c9e830b3e651a1e8004ef5027a94.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/EditLogFileInputStream.java

@@ -163,16 +163,6 @@ public class EditLogFileInputStream extends EditLogInputStream {
       } catch (EOFException eofe) {
         throw new LogHeaderCorruptException("No header found in log");
       }
-      if (logVersion == -1) {
-        // The edits in progress file is pre-allocated with 1MB of "-1" bytes
-        // when it is created, then the header is written. If the header is
-        // -1, it indicates the an exception occurred pre-allocating the file
-        // and the header was never written. Therefore this is effectively a
-        // corrupt and empty log.
-        throw new LogHeaderCorruptException("No header present in log (value " +
-            "is -1), probably due to disk space issues when it was created. " +
-            "The log has no transactions and will be sidelined.");
-      }
       // We assume future layout will also support ADD_LAYOUT_FLAGS
       if (NameNodeLayoutVersion.supports(
           LayoutVersion.Feature.ADD_LAYOUT_FLAGS, logVersion) ||

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLogLoader.java

@@ -1284,12 +1284,6 @@ public class FSEditLogLoader {
             + lastPos, t);
         in.resync();
         FSImage.LOG.warn("After resync, position is " + in.getPosition());
-        if (in.getPosition() <= lastPos) {
-          FSImage.LOG.warn("After resync, the position, {} is not greater " +
-              "than the previous position {}. Skipping remainder of this log.",
-              in.getPosition(), lastPos);
-          break;
-        }
         continue;
       }
       if (lastTxId == HdfsServerConstants.INVALID_TXID || txid > lastTxId) {

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/qjournal/server/TestJournal.java

@@ -28,7 +28,6 @@ import java.io.ByteArrayOutputStream;
 import java.io.DataOutputStream;
 import java.io.File;
 import java.io.IOException;
-import java.io.RandomAccessFile;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileUtil;
@@ -126,48 +125,6 @@ public class TestJournal {
     Assert.assertEquals(1, segmentState.getStartTxId());
   }
 
-  /**
-   * Test for HDFS-14557 to ensure that a edit file that failed to fully
-   * allocate and has a header byte of -1 is moved aside to allow startup
-   * to progress.
-   */
-  @Test
-  public void testEmptyEditsInProgressMovedAside() throws Exception {
-    // First, write 5 transactions to the journal
-    journal.startLogSegment(makeRI(1), 1,
-        NameNodeLayoutVersion.CURRENT_LAYOUT_VERSION - 1);
-    final int numTxns = 5;
-    byte[] ops = QJMTestUtil.createTxnData(1, 5);
-    journal.journal(makeRI(2), 1, 1, numTxns, ops);
-    // Now close the segment
-    journal.finalizeLogSegment(makeRI(3), 1, numTxns);
-
-    // Create a new segment creating a new edits_inprogress file
-    journal.startLogSegment(makeRI(4), 6,
-        NameNodeLayoutVersion.CURRENT_LAYOUT_VERSION - 1);
-    ops = QJMTestUtil.createTxnData(6, 5);
-    journal.journal(makeRI(5), 6, 6, numTxns, ops);
-    File eip = journal.getStorage().getInProgressEditLog(6);
-
-    // Now stop the journal without finalizing the segment
-    journal.close();
-
-    // Now "zero out" the EIP file with -1 bytes, similar to how it would
-    // appear if the pre-allocation failed
-    RandomAccessFile rwf = new RandomAccessFile(eip, "rw");
-    for (int i=0; i<rwf.length(); i++) {
-      rwf.write(-1);
-    }
-    rwf.close();
-
-    // Finally start the Journal again, and ensure the "zeroed out" file
-    // is renamed with a .empty extension
-    journal = new Journal(conf, TEST_LOG_DIR, JID, StartupOption.REGULAR,
-        mockErrorReporter);
-    File movedTo = new File(eip.getAbsolutePath()+".empty");
-    assertTrue(movedTo.exists());
-  }
-
   @Test (timeout = 10000)
   public void testEpochHandling() throws Exception {
     assertEquals(0, journal.getLastPromisedEpoch());

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestEditLogFileInputStream.java

@@ -28,7 +28,6 @@ import java.io.ByteArrayInputStream;
 import java.io.File;
 import java.io.IOException;
 import java.io.RandomAccessFile;
-import java.io.FileOutputStream;
 import java.net.HttpURLConnection;
 import java.net.URL;
 import java.util.EnumMap;
@@ -161,25 +160,4 @@ public class TestEditLogFileInputStream {
     }
     elis.close();
   }
-
-  /**
-   * Regression test for HDFS-14557 which verifies that an edit log filled
-   * with only "-1" bytes is moved aside and does not prevent the Journal
-   * node from starting.
-   */
-  @Test(timeout=60000)
-  public void testScanEditThatFailedDuringPreAllocate() throws Exception {
-    Configuration conf = new Configuration();
-    File editLog = new File(GenericTestUtils.getTempPath("testCorruptEditLog"));
-    FileOutputStream os = new FileOutputStream(editLog);
-    for (int i=0; i<1024; i++) {
-      os.write(-1);
-    }
-    os.close();
-    FSEditLogLoader.EditLogValidation val =
-        EditLogFileInputStream.scanEditLog(editLog, 1234, false);
-    assertEquals(true, val.hasCorruptHeader());
-    assertEquals(HdfsServerConstants.INVALID_TXID, val.getEndTxId());
-  }
-
 }