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  1. Hadoop HDFS
  2. HDFS-7858

Improve HA Namenode Failover detection on the client

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      In an HA deployment, Clients are configured with the hostnames of both the Active and Standby Namenodes.Clients will first try one of the NNs (non-deterministically) and if its a standby NN, then it will respond to the client to retry the request on the other Namenode.
      If the client happens to talks to the Standby first, and the standby is undergoing some GC / is busy, then those clients might not get a response soon enough to try the other NN.

      Proposed Approach to solve this :
      1) Use hedged RPCs to simultaneously call multiple configured NNs to decide which is the active Namenode.
      2) Subsequent calls, will invoke the previously successful NN.
      3) On failover of the currently active NN, the remaining NNs will be invoked to decide which is the new active

      Attachments

        1. HDFS-7858.1.patch
          22 kB
          Arun Suresh
        2. HDFS-7858.10.patch
          33 kB
          Arun Suresh
        3. HDFS-7858.10.patch
          33 kB
          Arun Suresh
        4. HDFS-7858.11.patch
          33 kB
          Arun Suresh
        5. HDFS-7858.12.patch
          38 kB
          Arun Suresh
        6. HDFS-7858.13.patch
          37 kB
          Arun Suresh
        7. HDFS-7858.2.patch
          19 kB
          Arun Suresh
        8. HDFS-7858.2.patch
          19 kB
          Arun Suresh
        9. HDFS-7858.3.patch
          18 kB
          Arun Suresh
        10. HDFS-7858.4.patch
          30 kB
          Arun Suresh
        11. HDFS-7858.5.patch
          30 kB
          Arun Suresh
        12. HDFS-7858.6.patch
          30 kB
          Arun Suresh
        13. HDFS-7858.7.patch
          33 kB
          Arun Suresh
        14. HDFS-7858.8.patch
          33 kB
          Arun Suresh
        15. HDFS-7858.9.patch
          33 kB
          Arun Suresh

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            asuresh Arun Suresh
            asuresh Arun Suresh
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