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  1. Hadoop HDFS
  2. HDFS-7285 Erasure Coding Support inside HDFS
  3. HDFS-8731

Erasure coding: For a small file missing and under replicated ec-block calculation is incorrect

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    • Sub-task
    • Status: Resolved
    • Major
    • Resolution: Duplicate
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    Description

      Write a small file (whose replica detail would be : one data replica and 3 parity replicas .)

      Now :
      totalReplicasPerBlock = 4
      targetFileReplication = 9 (calculated based on default RS-6-3 schema)

      Hence the small file ec-blocks is calculated as always missing and underreplicated. which is wrong... 

      targetFileReplication = (short) (ecSchema.getNumDataUnits() + ecSchema.getNumParityUnits());

            // count missing replicas / under replicated blocks
      if (totalReplicasPerBlock < targetFileReplication && totalReplicasPerBlock > 0) {
        res.missingReplicas += (targetFileReplication - totalReplicasPerBlock);
	res.numUnderReplicatedBlocks += 1;

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          is related to

          Sub-task - The sub-task of the issue HDFS-8563 Erasure Coding: fsck handles file smaller than a full stripe

          • Major - Major loss of function.
          • Resolved

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              andreina J.Andreina
              andreina J.Andreina
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              Dates

                Created:
                Updated:
                Resolved: