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  1. Hadoop HDFS
  2. HDFS-7714

Simultaneous restart of HA NameNodes and DataNode can cause DataNode to register successfully with only one NameNode.

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      In an HA deployment, DataNodes must register with both NameNodes and send periodic heartbeats and block reports to both. However, if NameNodes and DataNodes are restarted simultaneously, then this can trigger a race condition in registration. The end result is that the BPServiceActor for one NameNode terminates, but the BPServiceActor for the other NameNode remains alive. The DataNode process is then in a "half-alive" state where it only heartbeats and sends block reports to one of the NameNodes. This could cause a loss of storage capacity after an HA failover. The DataNode process would have to be restarted to resolve this.

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        1. HDFS-7714-001.patch
          2 kB
          Vinayakumar B
        2. HDFS-7714-002.patch
          1 kB
          Vinayakumar B

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              vinayakumarb Vinayakumar B
              cnauroth Chris Nauroth
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