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  1. Cassandra
  2. CASSANDRA-4937

CRAR improvements (object cache + CompressionMetadata chunk offset storage moved off-heap).

    Details

    • Type: Improvement
    • Status: Resolved
    • Priority: Major
    • Resolution: Fixed
    • Fix Version/s: 2.0 beta 1
    • Component/s: None
    • Labels:

      Description

      After good amount of testing on one of the clusters it was found that in order to improve read latency we need to minimize allocation rate that compression involves, that minimizes GC (as well as heap usage) and substantially decreases latency on read heavy workloads.

      I have also discovered that RAR skip cache harms performance in situation when reads are done in parallel with compaction working with relatively big SSTable files (few GB and more). The attached patch removes possibility to skip cache from compressed files (I can also add changes to RAR to remove skip cache functionality as a separate patch).

        Attachments

        1. 4937-v3.txt
          32 kB
          Jonathan Ellis
        2. CASSANDRA-4937.patch
          14 kB
          Pavel Yaskevich
        3. CASSANDRA-4937-trunk.patch
          31 kB
          Pavel Yaskevich
        4. CASSANDRA-4937-v4.patch
          34 kB
          Pavel Yaskevich

          Activity

            People

            • Assignee:
              xedin Pavel Yaskevich
              Reporter:
              xedin Pavel Yaskevich
              Reviewer:
              Yuki Morishita
            • Votes:
              0 Vote for this issue
              Watchers:
              3 Start watching this issue

              Dates

              • Created:
                Updated:
                Resolved: