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https://issues.apache.org/jira/browse/OAK-4069?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15732092#comment-15732092
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Marcel Reutegger commented on OAK-4069:
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The command serverStatus requires a user to have the clusterMonitor role. Can
you add warning when the connection is authenticated and the user does not have
that role assigned? I understand in that case the MongoDocumentStore would stay
with the default read concern even if the majority read concern option is
enabled on the server.
It would also be good to run some performance tests to see whether this new
default has an impact in a replica set.
> Use read concern majority when connected to a replica set
> ---------------------------------------------------------
>
> Key: OAK-4069
> URL: https://issues.apache.org/jira/browse/OAK-4069
> Project: Jackrabbit Oak
> Issue Type: Improvement
> Components: mongomk
> Reporter: Tomek Rękawek
> Assignee: Tomek Rękawek
> Labels: resilience
> Fix For: 1.6, 1.5.16
>
> Attachments: OAK-4069.patch
>
>
> Mongo 3.2 introduces new query option: {{readConcern}}. It allows to read
> only these changes that have been already committed to the majority of
> secondary instances.
> It prevents stale reads - a situation in which a change has been committed on
> the primary (and read from it), but due to the network partition a new
> primary is elected and the change is rolled back.
> We should use this new option (together with {{w:majority}} implemented in
> OAK-3554) when running Oak on MongoDB replica set.
> References:
> * [Jepsen: MongoDB stale
> reads|https://aphyr.com/posts/322-jepsen-mongodb-stale-reads]
> * [MongoDB documentation: Read Concern
> in|https://docs.mongodb.org/manual/reference/read-concern/]
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