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  1. Core Server
  2. SERVER-55412

Mirrored reads should propagate the shard version field

    • Fully Compatible
    • v5.0, v4.4
    • Service Arch 2021-06-28, Service Arch 2021-07-12, Service Arch 2021-08-09
    • 143
    • 4

      Mirrored reads are not propagating the shardVersion field to the command that it is send to the secondary nodes (e.g. find command ). This causes some performance issues (SERVER-47953 (follow-up of HELP-15484)) when a secondary steps up: due to the lack of the shard version, mirrored commands don't have the INCLUDE_SHARD_FILTER query phase, which is the phase that ends up refreshing the routing table.

      The goal of this task is to extend the void appendMirrorableRequest(BSONObjBuilder* bob) function to also propagate the shardVersion field.

      Affected versions: this issue is in 4.4 and master (the original concern was raised on 4.4).

            alex.li@mongodb.com Alex Li
            sergi.mateo-bellido@mongodb.com Sergi Mateo Bellido
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