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  1. Documentation
  2. DOCS-13363

Investigate changes in SERVER-45439: Add support for per operation hedging via an explicit read preference

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      Description

      Downstream Change Summary

      This ticket introduced a new $readPreference key "hedge" with two subkeys: "enabled" (default true) and "delay" (default true) . (Removed delay in DOCS-13429)

      Description of Linked Ticket

      Add support for operation hedging, as in SERVER-45432, with an explicit readPreference.

      The form of that readpreference should be:

      // some existing command
{
  ...,
  $readPreference: {
    mode: "nearest",
    hedge: {
      enabled: true,   // default value is true
      delay: true,        // default value is true
    }
}

      which should map to RemoteCommandRequestOnAny::HedgeOptions of

      • count = 1
      • as in implicit readPreference nearest

      Scope of changes

      Impact to Other Docs

      MVP (Work and Date)

      Resources (Scope or Design Docs, Invision, etc.)

            Assignee:
            Unassigned Unassigned
            Reporter:
            backlog-server-pm Backlog - Core Eng Program Management Team
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              Created:
              Updated:
              Resolved:
              4 years, 6 weeks, 5 days ago