[DOCS-13945] Clarify the purpose/usage of read write concern for user collections in "local" database. Created: 21/Sep/20  Updated: 30/Oct/23  Resolved: 17/Nov/20

Status: Closed
Project: Documentation
Component/s: manual, Server
Affects Version/s: None
Fix Version/s: Server_Docs_20231030

Type: Task Priority: Major - P3
Reporter: Suganthi Mani Assignee: Jeffrey Allen
Resolution: Fixed Votes: 0
Labels: None
Remaining Estimate: Not Specified
Time Spent: Not Specified
Original Estimate: Not Specified

Issue Links:
Related
is related to SERVER-49159 Return NotPrimaryOrSecondary if curre... Closed
Participants:
Days since reply: 3 years, 12 weeks, 1 day ago
Epic Link: DOCSP-11701
Story Points: 2

 Description   

I was wondering the impact of readConcern "after/atClusterTimestamp" for user collections in "local" database. Then, realized that
user writes to (unreplicated) collections in "local" database (except oplog ) are considered as ordered commits and those writes aren’t timestamped. So, reading those collection data with readConcern “after/atClusterTimestamp” doesn’t have any impact. To my surprise, we don't throw any error when a user provides writeConcern (like majority) or readConcern to "local" database collection instead we silently ignore those read-write concern values and execute the operation.



 Comments   
Comment by Githook User [ 17/Nov/20 ]

Author:

{'name': 'Jeff Allen', 'email': 'jeffrey.allen@mongodb.com'}

Message: (DOCS-13945): Read/Write concern not honored on local db
Branch: v4.2
https://github.com/mongodb/docs/commit/9a2b3d54a094602bf2e44d6a3652b36727ab262a

Comment by Githook User [ 17/Nov/20 ]

Author:

{'name': 'Jeff Allen', 'email': 'jeffrey.allen@mongodb.com'}

Message: (DOCS-13945): Read/Write concern not honored on local db
Branch: v5.0
https://github.com/mongodb/docs/commit/ca558e9efabad0345eddffb60dda698d9eaccd1a

Comment by Githook User [ 17/Nov/20 ]

Author:

{'name': 'Jeff Allen', 'email': 'jeffrey.allen@mongodb.com'}

Message: (DOCS-13945): Read/Write concern not honored on local db
Branch: master
https://github.com/mongodb/docs/commit/0c882bc324d43b82715d64546660f17ae6dd09c7

Comment by Evin Roesle [ 02/Nov/20 ]

jeffrey.allen Yes that is correct

Comment by Jeffrey Allen [ 26/Oct/20 ]

Hi suganthi.mani, evin.roesle, steven.vannelli, thanks for filing. Just confirming I'm understanding the scope of the ask: We want to update the read/write concern docs to reflect that specified read/write concerns are not honored when applied to the local db, and instead are (silently) ignored by MongoDB?

Comment by Evin Roesle [ 24/Sep/20 ]

We do not see users commonly reading from the "local" database so we should move forward with documenting the current behavior. This will make it clear to users what to expect if they provide a write/readConcern to the "local" database.

Generated at Thu Feb 08 08:09:06 UTC 2024 using Jira 9.7.1#970001-sha1:2222b88b221c4928ef0de3161136cc90c8356a66.