Details
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Improvement
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Status: Closed
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Major - P3
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Resolution: Done
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None
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None
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8
Description
As of server 2.8 and server 2.6.4, mongoS no longer pins secondary connections to allow changes in read preferences between queries.
Special attention, from ticket: "As these changes could not be backported to 2.6, a different fix was implemented specifically for 2.6: a new mongos server parameter, internalDBClientRSReselectNodePercentage was introduced. This can be set to any value from 0 to 100 (defaults to 0) and represents the probability (expressed in percentage) of a replica set connection in mongos to reevaluate replica set node selection from scratch, regardless of the compatibility of the current read preference to the last-used secondary node. Extra care should be taken since reselecting a replica set node will destroy the old connection and create a new connection. This means in extreme cases (for example, 100%), mongos can be creating and destroying connections for every read request."
Text re: pinning at http://docs.mongodb.org/manual/core/read-preference-mechanics/ should be changed.
See linked.
Attachments
Issue Links
- documents
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SERVER-9788 mongos does not re-evaluate read preference once a valid replica set member is chosen
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- Closed
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