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https://issues.apache.org/jira/browse/OAK-4069?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15747557#comment-15747557
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Marcel Reutegger commented on OAK-4069:
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Patch looks good. I noticed just one minor issue with
{{DocumentMK.Builder.setMongoDB(DB, MongoStatus, int)}}. It does not set
{{mongoStatus}} in the builder and {{MongoDocumentStore}} therefore needs to
calculate a new status in the constructor.
> 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-4069-2.patch, OAK-4069-3.patch, 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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