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  1. Core Server
  2. SERVER-50144

Removing a shard with in-progress migration coordinators can leave permanently pending config.rangeDeletions document on recipient

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    Details

    • Type: Bug
    • Status: Open
    • Priority: Major - P3
    • Resolution: Unresolved
    • Affects Version/s: None
    • Fix Version/s: Backlog
    • Component/s: Sharding
    • Labels:
    • Operating System:
      ALL
    • Sprint:
      Sharding 2020-11-02, Sharding 2020-11-16, Sharding 2020-11-30, Sharding 2020-12-14, Sharding 2020-12-28, Sharding 2021-01-11, Sharding EMEA 2021-10-04, Sharding EMEA 2021-10-18
    • Linked BF Score:
      143

      Description

      The following scenario can occur:

      1. Migration of a chunk from shard X to shard Y completes with commit/abort and the migration coordinator on shard X persists the decision
      2. Shard X is removed and shut down before the migration coordinator updates config.rangeDeletions on shard Y
      3. Shard Y is left with document in config.rangeDeletions corresponding to that migration with a 'pending: true' flag

      The presence of this document will permanently prevent any migrations to shard Y for chunks overlapping this chunk.

      In the case where the migration aborted after migrating some documents to shard Y, this will also leave documents in this chunk orphaned on shard Y.

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              Assignee:
              backlog-server-serverless Backlog - Server Serverless
              Reporter:
              matthew.saltz Matthew Saltz
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                Dates

                Created:
                Updated: