Alexey Serbin has posted comments on this change. ( 
http://gerrit.cloudera.org:8080/22133 )

Change subject: KUDU-3571: fix flakiness in 
AutoIncrementingItest.BootstrapNoWalsNoData
......................................................................


Patch Set 1:

(2 comments)

http://gerrit.cloudera.org:8080/#/c/22133/1//COMMIT_MSG
Commit Message:

http://gerrit.cloudera.org:8080/#/c/22133/1//COMMIT_MSG@10
PS1, Line 10: unhealthy or lagging replicas
I'm curious: what 'deterministic' means in this context?

Write operations are being replicated regardless of regular/periodic Raft 
heartbeating -- the leader replica sends Raft updates right away during the 
replication phase, it doesn't wait for next periodic Raft heartbeat interval, 
no.

If introducing a delay, it might be anything here, IIUC. Setting it to the Raft 
heartbeat interval just adds extra confusion.

And I don't think this current approach in PS5 or PS6 is going to address the 
flakiness -- it might still pop up under some extreme conditions.  If going the 
route of waiting for all the replicas to converge and doing it reliably, one 
might take a look at various methods in test scaffolding like 
WaitForServersToAgree() and AssertAllReplicasAgree() in

What's the problem with the original approach that Yifan used in PS1?

> Limiting to only leader replica might be concerning

Ashwani, Abhishek -- could you add more details on your concerns around this?

Thanks!


http://gerrit.cloudera.org:8080/#/c/22133/6/src/kudu/integration-tests/auto_incrementing-itest.cc
File src/kudu/integration-tests/auto_incrementing-itest.cc:

http://gerrit.cloudera.org:8080/#/c/22133/6/src/kudu/integration-tests/auto_incrementing-itest.cc@446
PS6, Line 446:   // Restart the cluster.
             :   cluster_->Shutdown(
The replication of writes happens regardless of periodic Raft heartbeating.  
Also, even with this extra delay there isn't a guarantee to have everything 
replicated across all the existing replicas -- this extra delay might provide 
some sense of security, but I'm not sure it's able to address the issue 
underlying issue.



--
To view, visit http://gerrit.cloudera.org:8080/22133
To unsubscribe, visit http://gerrit.cloudera.org:8080/settings

Gerrit-Project: kudu
Gerrit-Branch: master
Gerrit-MessageType: comment
Gerrit-Change-Id: I5bd387c82b632dbb77aa5a45f831273392ae05b4
Gerrit-Change-Number: 22133
Gerrit-PatchSet: 1
Gerrit-Owner: Yifan Zhang <[email protected]>
Gerrit-Reviewer: Abhishek Chennaka <[email protected]>
Gerrit-Reviewer: Alexey Serbin <[email protected]>
Gerrit-Reviewer: Ashwani Raina <[email protected]>
Gerrit-Reviewer: Kudu Jenkins (120)
Gerrit-Reviewer: Yifan Zhang <[email protected]>
Gerrit-Comment-Date: Wed, 04 Dec 2024 06:32:08 +0000
Gerrit-HasComments: Yes

Reply via email to