[DOCS-10539] Docs for SERVER-28948: open up secondaries to checking shardVersion Created: 18/Jul/17  Updated: 29/Oct/23  Resolved: 06/Nov/17

Status: Closed
Project: Documentation
Component/s: None
Affects Version/s: None
Fix Version/s: 3.5.11

Type: Task Priority: Major - P3
Reporter: Emily Hall Assignee: Kevin Albertson
Resolution: Fixed Votes: 0
Labels: None
Remaining Estimate: Not Specified
Time Spent: Not Specified
Original Estimate: Not Specified

Issue Links:
Documented
documents SERVER-28948 open up secondaries to checking shard... Closed
Duplicate
Participants:
Days since reply: 6 years, 14 weeks, 2 days ago
Epic Link: DOCS: 3.6 Server

 Description   

Documentation Request Summary:

This ticket makes shard secondaries participate in the shard versioning protocol. This makes them:
1) return an error for a request from mongos if the mongos's routing table cache is more stale than the secondary's, so that mongos refreshes its cache and re-targets
2) filter results using their (new) routing table cache, so that they don't return oprhaned documents for versioned requests

The following commands were previously unversioned against secondaries, but are now versioned:

  • aggregate
  • count
  • find

The following commands are still unversioned against secondaries, because they were unversioned against primaries:

  • geoNear
  • distinct

Finally, note that the following commands are not supported on sharded collections:

  • group


 Comments   
Comment by Githook User [ 06/Nov/17 ]

Author:

{'name': 'Kevin Albertson', 'username': 'kevinAlbs', 'email': 'kevin.albertson@10gen.com'}

Message: DOCS-10539 geoNear and distinct may return orphans
Branch: master
https://github.com/mongodb/docs/commit/1dff0789ca4082f4d8f2d50f36385ccf24e418ff

Comment by Kevin Albertson [ 23/Oct/17 ]

Discussed with Tess and Esha. SERVER-3645 is still applicable, so count without a predicate may still overcount if there are orphaned documents. It might be worth documenting the current status of these commands to avoid any surprises to users:

We already document that count may return an inaccurate count when there are orphaned documents. We should add similar notes to geoNear and distinct

Generated at Thu Feb 08 08:00:48 UTC 2024 using Jira 9.7.1#970001-sha1:2222b88b221c4928ef0de3161136cc90c8356a66.