1. HBase
  2. HBASE-11620

Record the class name of Writer in WAL header so that only proper Reader can open the WAL file


    • Type: Bug Bug
    • Status: Closed
    • Priority: Critical Critical
    • Resolution: Fixed
    • Affects Version/s: 0.98.4
    • Fix Version/s: 0.99.0, 0.98.5, 2.0.0
    • Component/s: None
    • Labels:
    • Hadoop Flags:


      Reported by Kiran in this thread: "HBase file encryption, inconsistencies observed and data loss"

      After step 4 ( i.e disabling of WAL encryption, removing SecureProtobufReader/Writer and restart), read of encrypted WAL fails mainly due to EOF exception at Basedecoder. This is not considered as error and these WAL are being moved to /oldWALs.

      Following is observed in log files:

      2014-07-30 19:44:29,254 INFO  [RS_LOG_REPLAY_OPS-HOST-16:15264-1] wal.HLogSplitter: Splitting hlog: hdfs://HOST-16:18020/hbase/WALs/HOST-16,15264,1406725441997-splitting/HOST-16%2C15264%2C1406725441997.1406725444017, length=172
      2014-07-30 19:44:29,254 INFO  [RS_LOG_REPLAY_OPS-HOST-16:15264-1] wal.HLogSplitter: DistributedLogReplay = false
      2014-07-30 19:44:29,313 INFO  [RS_LOG_REPLAY_OPS-HOST-16:15264-1] util.FSHDFSUtils: Recovering lease on dfs file hdfs://HOST-16:18020/hbase/WALs/HOST-16,15264,1406725441997-splitting/HOST-16%2C15264%2C1406725441997.1406725444017
      2014-07-30 19:44:29,315 INFO  [RS_LOG_REPLAY_OPS-HOST-16:15264-1] util.FSHDFSUtils: recoverLease=true, attempt=0 on file=hdfs://HOST-16:18020/hbase/WALs/HOST-16,15264,1406725441997-splitting/HOST-16%2C15264%2C1406725441997.1406725444017 after 1ms
      2014-07-30 19:44:29,429 DEBUG [RS_LOG_REPLAY_OPS-HOST-16:15264-1-Writer-0] wal.HLogSplitter: Writer thread Thread[RS_LOG_REPLAY_OPS-HOST-16:15264-1-Writer-0,5,main]: starting
      2014-07-30 19:44:29,429 DEBUG [RS_LOG_REPLAY_OPS-HOST-16:15264-1-Writer-1] wal.HLogSplitter: Writer thread Thread[RS_LOG_REPLAY_OPS-HOST-16:15264-1-Writer-1,5,main]: starting
      2014-07-30 19:44:29,430 DEBUG [RS_LOG_REPLAY_OPS-HOST-16:15264-1-Writer-2] wal.HLogSplitter: Writer thread Thread[RS_LOG_REPLAY_OPS-HOST-16:15264-1-Writer-2,5,main]: starting
      2014-07-30 19:44:29,591 ERROR [RS_LOG_REPLAY_OPS-HOST-16:15264-1] codec.BaseDecoder: Partial cell read caused by EOF: java.io.IOException: Premature EOF from inputStream
      2014-07-30 19:44:29,592 INFO  [RS_LOG_REPLAY_OPS-HOST-16:15264-1] wal.HLogSplitter: Finishing writing output logs and closing down.
      2014-07-30 19:44:29,592 INFO  [RS_LOG_REPLAY_OPS-HOST-16:15264-1] wal.HLogSplitter: Waiting for split writer threads to finish
      2014-07-30 19:44:29,592 INFO  [RS_LOG_REPLAY_OPS-HOST-16:15264-1] wal.HLogSplitter: Split writers finished
      2014-07-30 19:44:29,592 INFO  [RS_LOG_REPLAY_OPS-HOST-16:15264-1] wal.HLogSplitter: Processed 0 edits across 0 regions; log file=hdfs://HOST-16:18020/hbase/WALs/HOST-16,15264,1406725441997-splitting/HOST-16%2C15264%2C1406725441997.1406725444017 is corrupted = false progress failed = false

      To fix this, we need to propagate EOF exception to HLogSplitter. Any suggestions on the fix?

      -------- (end of quote from Kiran)

      In BaseDecoder#rethrowEofException() :

          if (!isEof) throw ioEx;
          LOG.error("Partial cell read caused by EOF: " + ioEx);
          EOFException eofEx = new EOFException("Partial cell read");
          throw eofEx;

      throwing EOFException would not propagate the "Partial cell read" condition to HLogSplitter which doesn't treat EOFException as an error.

      I think IOException should be thrown above - HLogSplitter#getNextLogLine() would translate the IOEx to CorruptedLogFileException.

      1. 11620-v7.txt
        30 kB
        Ted Yu
      2. 11620-v6.txt
        30 kB
        Ted Yu
      3. 11620-v6.txt
        30 kB
        Ted Yu
      4. 11620-v5.txt
        27 kB
        Ted Yu
      5. 11620-v4.txt
        26 kB
        Ted Yu
      6. 11620-v3.txt
        25 kB
        Ted Yu
      7. 11620-v2.txt
        20 kB
        Ted Yu
      8. 11620-v1.txt
        0.8 kB
        Ted Yu
      9. 11620-0.98-v7.txt
        29 kB
        Ted Yu
      10. 11620-0.98-v6.txt
        29 kB
        Ted Yu


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          • Assignee:
            Ted Yu
            Ted Yu
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