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  1. Hadoop HDFS
  2. HDFS-14277

[SBN read] Observer benchmark results



    • Task
    • Status: Open
    • Major
    • Resolution: Unresolved
    • 2.10.0, 3.3.0
    • None
    • ha, namenode
    • None
    • Hardware: 4-node cluster, each node has 4 core, Xeon 2.5Ghz, 25GB memory.
      Software: CentOS 7.4, CDH 6.0 + Consistent Reads from Standby, Kerberos, SSL, RPC encryption + Data Transfer Encryption, Cloudera Navigator.


      Ran a few benchmarks and profiler (VisualVM) today on an Observer-enabled cluster. Would like to share the results with the community. The cluster has 1 Observer node.


      Generate 1 million files and send fileStatus RPCs.

      hadoop org.apache.hadoop.hdfs.server.namenode.NNThroughputBenchmark -fs <namenode>  -op fileStatus -threads 100 -files 1000000 -useExisting -keepResults

      Kerberos, SSL, RPC encryption, Data Transfer Encryption enabled:

      Node fileStatus (Ops per sec)
      Active NameNode 4865
      Observer 3996

      Kerberos, SSL:

      Node fileStatus (Ops per sec)
      Active NameNode 7078
      Observer 6459


      • due to the edit tailing overhead, Observer node consume 30% CPU utilization even if the cluster is idle.
      • While Active NN has less than 1ms RPC processing time, Observer node has > 5ms RPC processing time. I am still looking for the source of the longer processing time. The longer RPC processing time may be the cause for the performance degradation compared to that of Active NN. Note the cluster has Cloudera Navigator installed which adds additional overhead to RPC processing time.
      • GlobalStateIdContext#isCoordinatedCall() pops up as one of the top hotspots in the profiler. 



        1. Screen Shot 2019-02-14 at 11.50.37 AM.png
          399 kB
          Wei-Chiu Chuang
        2. observer RPC queue processing time.png
          163 kB
          Wei-Chiu Chuang
        3. Observer profiler.png
          457 kB
          Wei-Chiu Chuang

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              Unassigned Unassigned
              weichiu Wei-Chiu Chuang
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