Never replicate Operation FCV in the oplog in FCV <8.2

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    • Type: Task
    • Resolution: Unresolved
    • Priority: Major - P3
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    • Affects Version/s: 8.3.0-rc0
    • Component/s: None
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    • Catalog and Routing
    • CAR Team 2025-10-27
    • 🟩 Routing and Topology
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      In SERVER-102965, we implemented replication of Operation FCV (OFCV) in the oplog through the versionContext field.

      This could be done unconditionally since we OFCV was only used by ShardingDDLCoordinators started in ServerFCV≥8.2, and we drained those at the end of the upgrade/downgrade.

       

      In SERVER-111448 we will add a RAII helper that allows shard-local operations to acquire an OFCV even in ServerFCV=8.0. This OFCV it is only an in-memory state and can not be replicated (since 8.0 binaries do not understand this field), so we need to gate replication to the oplog behind a feature flag.

            Assignee:
            Joan Bruguera Micó
            Reporter:
            Joan Bruguera Micó
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              Created:
              Updated: