[kudu-CR] [clock] change clock source selection for 'auto'

["Andrew Wong (Code Review)" <ge...@cloudera.org>]

Andrew Wong has posted comments on this change. ( http://gerrit.cloudera.org:8080/17582 )

Change subject: [clock] change clock source selection for 'auto'
......................................................................


Patch Set 3: Code-Review+1

(1 comment)

http://gerrit.cloudera.org:8080/#/c/17582/3/src/kudu/clock/hybrid_clock.cc
File src/kudu/clock/hybrid_clock.cc:

http://gerrit.cloudera.org:8080/#/c/17582/3/src/kudu/clock/hybrid_clock.cc@476
PS3, Line 476:       // Switch to the built-in NTP client unless the set of reference servers
> Sure: it's possible to detect that, but it will require extra time waiting 
One of the nice things about the current iteration of this is that the selected time source is entirely dependent on the configured environment, regardless of any networking woes.

Depending on what we want "auto" to be, that might be good enough. If it is meant to pick the best clock for the current environment and current configs, we seem to already be doing the right thing. If the goal is to reduce the number of times there are instances where an unsynchronized clock can crash a server, I suppose that's another story, and that would bring into question the robustness of the built-in clock vs the system clock for initial synchronization. What are our expectations of the builtin's ability to synchronize vs typical "system" deployments? With default deployments, would we expect that if the system client can't synchronize, the built-in client would also have issues synchronizing?



-- 
To view, visit http://gerrit.cloudera.org:8080/17582
To unsubscribe, visit http://gerrit.cloudera.org:8080/settings

Gerrit-Project: kudu
Gerrit-Branch: master
Gerrit-MessageType: comment
Gerrit-Change-Id: I72cb54c488b2aa2c73acd6e6e5f6e50dd5811175
Gerrit-Change-Number: 17582
Gerrit-PatchSet: 3
Gerrit-Owner: Alexey Serbin <as...@cloudera.com>
Gerrit-Reviewer: Alexey Serbin <as...@cloudera.com>
Gerrit-Reviewer: Andrew Wong <aw...@cloudera.com>
Gerrit-Reviewer: Grant Henke <gr...@apache.org>
Gerrit-Reviewer: Kudu Jenkins (120)
Gerrit-Reviewer: Tidy Bot (241)
Gerrit-Comment-Date: Tue, 06 Jul 2021 22:09:25 +0000
Gerrit-HasComments: Yes