[SERVER-30066] Alert users when adding a downed node to a replica set Created: 10/Jul/17 Updated: 27/Oct/23 Resolved: 01/Sep/17 |
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| Status: | Closed |
| Project: | Core Server |
| Component/s: | Replication |
| Affects Version/s: | 3.0.0 |
| Fix Version/s: | None |
| Type: | Improvement | Priority: | Major - P3 |
| Reporter: | Benjamin Appréderisse | Assignee: | Spencer Brody (Inactive) |
| Resolution: | Works as Designed | Votes: | 0 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Participants: |
| Description |
| Comments |
| Comment by Spencer Brody (Inactive) [ 01/Sep/17 ] | |||||||||||||||||
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The way this worked in 2.6 was that the node would send a message to every other node in the set as part of processing the reconfig and would report the other node as down if it didn't get a response. This behavior was removed as we don't want reconfigs to be performing blocking network i/o as part of their operation - it slows down and increases the complexity of the reconfig, plus its notion of whether it will consider the other nodes down is quite brittle as it's dependent only on missing this single message. The best way to know whether one node considers the other nodes in its set to be down is to check the results of running replSetGetStatus. ReplSetGetStatus will only report another node as down if the node it's run against hasn't heard any replication messages from the other node within the election timeout, which is a more robust way to determine whether a node is down and is based on the same state tracking that is used by the rest of the replication system. | |||||||||||||||||
| Comment by Kelsey Schubert [ 19/Jul/17 ] | |||||||||||||||||
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Hi bappr, This behavior appears to be consistent between rs.addArb() and rs.add():
I see that a while back, in MongoDB 2.6, we provided additional information:
Therefore, I'm repurposing this ticket as an improvement request to restore this functionality and sending it to the replication team to consider. Please let me know if this does not address your concerns. Kind regards, |