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    Type:New Feature 
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    Resolution: Fixed
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    Priority:Major - P3 
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    Affects Version/s: None
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    Component/s: Upgrade/Downgrade
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    None
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        Fully Compatible
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        Storage NYC 2018-03-12
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        None
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Currently, only incoming connections from last-stable binary version clients are closed upon bumping the featureCompatibilityVersion. Outgoing connections to last-stable binary version servers should be closed as well.
- depends on
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                    SERVER-32601 Add the ability to tag and close outgoing connections within a sharded cluster -         
- Closed
 
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- has to be done before
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                    SERVER-32911 Remove heartbeat version field, "hbv", from the heartbeat command once outgoing connections to last-stable binaries are closed on FCV upgrade -         
- Backlog
 
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- is duplicated by
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                    SERVER-32910 Update multiVersion/feature_compatibility_version_lagging_secondary.js to use v3.6 and v4.0 binaries, rather than v3.4 and v4.0 -         
- Closed
 
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- is related to
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                    SERVER-32729 Bump the replica set heartbeat version so a latest-FCV primary does not attempt to talk to a last-stable binary secondary -         
- Closed
 
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