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  1. Hadoop HDFS
  2. HDFS-8277

Safemode enter fails when Standby NameNode is down



    • Type: Bug
    • Status: Patch Available
    • Priority: Major
    • Resolution: Unresolved
    • Affects Version/s: 2.6.0
    • Fix Version/s: None
    • Component/s: ha, namenode
    • Labels:
    • Environment:

      HDP 2.2.0


      HDFS fails to enter safemode when the Standby NameNode is down (eg. due to AMBARI-10536).

      hdfs dfsadmin -safemode enter
      safemode: Call From nn2/x.x.x.x to nn1:8020 failed on connection exception: java.net.ConnectException: Connection refused; For more details see:  http://wiki.apache.org/hadoop/ConnectionRefused

      This appears to be a bug in that it's not trying both NameNodes like the standard hdfs client code does, and is instead stopping after getting a connection refused from nn1 which is down. I verified normal hadoop fs writes and reads via cli did work at this time, using nn2. I happened to run this command as the hdfs user on nn2 which was the surviving Active NameNode.

      After I re-bootstrapped the Standby NN to fix it the command worked as expected again.


        1. HDFS-8277-safemode-edits.patch
          15 kB
          Surendra Singh Lilhore
        2. HDFS-8277.patch
          1 kB
          Surendra Singh Lilhore
        3. HDFS-8277_5.patch
          6 kB
          Jianfei Jiang
        4. HDFS-8277_4.patch
          2 kB
          Surendra Singh Lilhore
        5. HDFS-8277_3.patch
          2 kB
          Surendra Singh Lilhore
        6. HDFS-8277_2.patch
          3 kB
          Surendra Singh Lilhore
        7. HDFS-8277_1.patch
          1 kB
          Surendra Singh Lilhore

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              • Assignee:
                jiangjianfei Jianfei Jiang
                harisekhon Hari Sekhon
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