[DOCS-638] Document effect of hidden secondary being most current in failover scenario Created: 24/Oct/12  Updated: 30/Oct/23  Resolved: 06/Nov/12

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

Type: Improvement Priority: Major - P3
Reporter: Ian Daniel Assignee: Sam Kleinman (Inactive)
Resolution: Done Votes: 0
Labels: None
Remaining Estimate: Not Specified
Time Spent: Not Specified
Original Estimate: Not Specified
Environment:

Replica set failover


Issue Links:
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Participants:
Days since reply: 11 years, 15 weeks, 1 day ago

 Description   

In the event of a replica set failover, if a hidden secondary is more current that the visible secondaries, one of the visible secondaries will not be immediately elected primary, but will instead catch up to the hidden secondary before one of them is elected primary.

The same is true for a secondary with priority of 0, even if not hidden.

This behaviour is implied, but not spelt out explicitly, in the Replication Internals - Elections documentation:

A member of the set will veto an election under the following conditions:

  • <snip/>
  • If the member seeking an election is not up-to-date with the most recent operation accessible in the replica set.

It warrants explicit mention, however, as users could easily incorrectly assume that the behaviour is otherwise: that the visible secondary becomes primary immediately and hence data is lost (data that the hidden secondary had and the visible secondary did not).

I suggest documenting it in the following pages:



 Comments   
Comment by auto [ 06/Nov/12 ]

Author:

{u'date': u'2012-11-06T22:47:31Z', u'email': u'samk@10gen.com', u'name': u'Sam Kleinman'}

Message: minor: DOCS-638 note about buildindexes-false syncing
Branch: master
https://github.com/mongodb/docs/commit/9632c5de7792be54a2382dc832747e35c9ce4a77

Comment by auto [ 06/Nov/12 ]

Author:

{u'date': u'2012-11-06T22:20:44Z', u'email': u'samk@10gen.com', u'name': u'Sam Kleinman'}

Message: DOCS-638 replica set election update regarding secondary only members
Branch: master
https://github.com/mongodb/docs/commit/0299ca89566d0e2c5b654899788605872bbb5149

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