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Type: New Feature
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Resolution: Done
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Priority: Major - P3
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Affects Version/s: None
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Component/s: None
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None
Implementation should follow the (10gen internal) spec defined here:
https://wiki.10gen.com/display/10GEN/Driver+Read+Semantics
PLEASE NOTE: The definition of SECONDARY is changing due to this spec. The SECONDARY option now means the same thing as SECONDARY_ONLY. A SECONDARY_PREFERRED option is being added that matches what SECONDARY used to do. SECONDARY_ONLY is deprecated in PyMongo 2.3.
These are the new preferences and their meaning:
"PRIMARY": Read from primary only. All operations produce an error (throw an exception where applicable) if primary is unavailable. Cannot be combined with tags. This is the default. "PRIMARY_PREFERRED": Read from primary if available, otherwise a secondary. "SECONDARY": Read from secondary if available, otherwise error. "SECONDARY_ONLY" (deprecated): Synonym for "SECONDARY" "SECONDARY_PREFERRED": Read from a secondary if available, otherwise read from the primary. "NEAREST": Read from any member.
Also need to add better read preferences docs. A new examples page would probably be best.
- is depended on by
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PYTHON-368 mongos high availability and failover
- Closed