Uploaded image for project: 'HBase'
  1. HBase
  2. HBASE-2821

Keep young storefiles at lower replication



    • Improvement
    • Status: Closed
    • Major
    • Resolution: Later
    • None
    • None
    • regionserver
    • None


      jgray and I were brainstorming some ideas about this:

      In a typical heavy-write scenario, many store files do not last very long. They're flushed and then within a small number of seconds a compaction runs and they get deleted. For these "short lifetime" store files, it's less likely that a failure will occur during the window in which they're valid. So, I think we can consider some optimizations like the following:

      • Flush files at replication count 2. Scan once a minute for any store files in the region that are older than 2 minutes. If they're found, increase their replication to 3. (alternatively, queue them to avoid scanning)
      • More dangerous: flush files at replication count 1, but don't count them when figuring log expiration. So, if they get lost, we force log splitting to recover.

      The performance gain here is that we avoid the network and disk transfer of writing the third replica for a file that we're just about to delete anyway.


        1. storefile_age.pl
          0.8 kB
          Todd Lipcon
        2. lifetime-distribution.png
          5 kB
          Todd Lipcon
        3. HBASE-2821.patch
          28 kB
          Andrew Kyle Purtell
        4. HBASE-2821.patch
          29 kB
          Andrew Kyle Purtell
        5. HBASE-2821.patch
          29 kB
          Andrew Kyle Purtell

        Issue Links



              Unassigned Unassigned
              tlipcon Todd Lipcon
              0 Vote for this issue
              7 Start watching this issue