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  1. HBase
  2. HBASE-14070

Hybrid Logical Clocks for HBase

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Details

    • New Feature
    • Status: Reopened
    • Major
    • Resolution: Unresolved
    • None
    • None
    • None
    • None

    Description

      HBase and Phoenix uses systems physical clock (PT) to give timestamps to events (read and writes). This works mostly when the system clock is strictly monotonically increasing and there is no cross-dependency between servers clocks. However we know that leap seconds, general clock skew and clock drift are in fact real.

      This jira proposes using Hybrid Logical Clocks (HLC) as an implementation of hybrid physical clock + a logical clock. HLC is best of both worlds where it keeps causality relationship similar to logical clocks, but still is compatible with NTP based physical system clock. HLC can be represented in 64bits.

      A design document is attached and also can be found here:
      https://docs.google.com/document/d/1LL2GAodiYi0waBz5ODGL4LDT4e_bXy8P9h6kWC05Bhw/edit#

      Attachments

        1. HBASE-14070.master.001.patch
          284 kB
          Sai Teja Ranuva
        2. HybridLogicalClocksforHBaseandPhoenix.docx
          24 kB
          Andrew Kyle Purtell
        3. HybridLogicalClocksforHBaseandPhoenix.pdf
          334 kB
          Enis Soztutar

        Issue Links

          incorporates

          Sub-task - The sub-task of the issue HBASE-16148 Hybrid Logical Clocks(placeholder for running tests)

          • Minor - Minor loss of function, or other problem where easy workaround is present.
          • Open
          is related to

          Bug - A problem which impairs or prevents the functions of the product. PHOENIX-2124 Hybrid Logical Clocks for Phoenix

          • Major - Major loss of function.
          • Open

          Bug - A problem which impairs or prevents the functions of the product. HBASE-9879 Can't undelete a KeyValue

          • Major - Major loss of function.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. HBASE-14054 Acknowledged writes may get lost if regionserver clock is set backwards

          • Major - Major loss of function.
          • Closed

          New Feature - A new feature of the product, which has yet to be developed. HBASE-9905 Enable using seqId as timestamp

          • Major - Major loss of function.
          • Closed
          relates to

          Sub-task - The sub-task of the issue HBASE-6833 [WINDOWS] Java Milisecond precision on Windows

          • Major - Major loss of function.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. HBASE-8927 Use nano time instead of mili time everywhere

          • Major - Major loss of function.
          • Closed

          Brainstorming - A place to record back and forth on notions not yet formed enough to make a 'New Feature' or 'Task' HBASE-10247 Client promises about timestamps

          • Minor - Minor loss of function, or other problem where easy workaround is present.
          • Closed
          links to

          Web Link Current Status of HLC

          Web Link review board

          Web Link Review Board (master)

          Activity

            People

              Unassigned Unassigned
              enis Enis Soztutar
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              Dates

                Created:
                Updated: