[HDFS-12209] VolumeScanner scan cursor not save periodic

• Type: Bug
• Status: Patch Available
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 2.6.0
• Component/s: hdfs

Environment

cdh5.4.0

• Assignee: Unassigned
• Reporter: fatkun
• Created: 28/Jul/17 07:43
• Updated: 02/Oct/19 17:15

Description

The bug introduce from HDFS-7430 , the time is not same, one is monotonicMs and other is clock time. It should use Time.now() both

VolumeScanner.java

        long saveDelta = monotonicMs - curBlockIter.getLastSavedMs();
        if (saveDelta >= conf.cursorSaveMs) {
          LOG.debug("{}: saving block iterator {} after {} ms.",
                  this, curBlockIter, saveDelta);
          saveBlockIterator(curBlockIter);
        }

curBlockIter.getLastSavedMs() init here

FsVolumeImpl.java

    BlockIteratorState() {
      lastSavedMs = iterStartMs = Time.now();
      curFinalizedDir = null;
      curFinalizedSubDir = null;
      curEntry = null;
      atEnd = false;
    }

Issue Links

• is broken by: HDFS-7430 Rewrite the BlockScanner to use O(1) memory and use multiple threads