Details
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Task
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Status: Closed
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Major - P3
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Resolution: Fixed
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None
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None
Description
Description
After SERVER-45432 and SERVER-45434 are completed, mongos will perform hedged reads by default when the readPreference mode is “nearest”.
Description of Linked Ticket
Add support for implicit delay selection and opt in to hedge options when using readPreference nearest.
For all queries with readPreference mode "nearest", pass hedge options of:
- count = 1
- delay = as computed by
SERVER-45449
Scope of changes
Update Doc | DOCS ticket | SERVER/DRIVER ticket |
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Server Selection | ||
Read pref nearest | ||
readHedgingMode (on/off) parameter | ||
maxTimeMSForHedgedReads | ||
Mongo.setReadPref | |
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cursor.readPref | |
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Blurb about driver helper methods and not connection string | |
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Impact to Other Docs
MVP (Work and Date)
Resources (Scope or Design Docs, Invision, etc.)
Attachments
Issue Links
- documents
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SERVER-45440 Add support for implicit operation hedging when using readPreference mode nearest
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- Closed
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- is related to
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DRIVERS-723 Driver support for server Hedged Reads
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- Closed
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- related to
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DOCS-13375 Investigate changes in SERVER-45437: Add readHedgingMode serverParameter
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- Closed
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DOCS-13506 Investigate changes in SERVER-46567: Update shell methods Mongo.setReadPref and cursor.readPref to support hedging
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- Closed
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