[DOCS-4045] Clarify that write concern majority includes all members Created: 16/Sep/14 Updated: 18/Nov/14 Resolved: 17/Nov/14 |
|
| Status: | Closed |
| Project: | Documentation |
| Component/s: | manual |
| Affects Version/s: | None |
| Fix Version/s: | v1.3.12, v1.3.14 |
| Type: | Bug | Priority: | Critical - P2 |
| Reporter: | Jeremy Mikola | Assignee: | Sam Kleinman (Inactive) |
| Resolution: | Done | Votes: | 0 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Issue Links: |
|
||||
| Participants: | |||||
| Days since reply: | 9 years, 13 weeks, 1 day ago | ||||
| Description |
|
In PHP-1222, a user expected that the "majority" write concern would only consider data-bearing nodes. scotthernandez provided me with a helpful explanation for why it needs to count all nodes, as the goal is to avoid data loss due to roll-back. It would be helpful if we explained this with a blurb in the documentation. http://docs.mongodb.org/manual/core/write-concern/ talks about "majority" persisting data to storage nodes, but it doesn't address arbiters at all. Obviously, they don't hold data, but they are counted in determining the "majority". He also clarified that "majority" means something else when referring to election voting (it depends more on voters and vote weights than physical nodes), but I don't think we need to clarify that with this ticket. |
| Comments |
| Comment by Githook User [ 18/Nov/14 ] |
|
Author: {u'username': u'tychoish', u'name': u'Sam Kleinman', u'email': u'samk@10gen.com'}Message: |
| Comment by Kevin Pulo [ 12/Nov/14 ] |
|
This change is not correct. w:majority does NOT refer to a majority of the voting members. w:majority means a majority of ALL replica set members. The code is very straightforward on this, it is basically just "number of members / 2 + 1" (except if there are more arbiters than non-arbiters). Please update the language to make it clear that when computing w:majority, all members are counted, including arbiters, non-voting members, slave delayed members, and hidden members. Note that this behaviour is changing in 2.8 to be a majority of voting members, see |
| Comment by Githook User [ 03/Oct/14 ] |
|
Author: {u'username': u'tychoish', u'name': u'Sam Kleinman', u'email': u'samk@10gen.com'}Message: |