Alexey Serbin has posted comments on this change. ( 
http://gerrit.cloudera.org:8080/14897 )

Change subject: WIP [master] KUDU-3016 don't lump together updates on all 
tablet reports
......................................................................


Patch Set 1:

(1 comment)

> (2 comments)
 >
 > Seems like a reasonable approach to me. I'd like to understand the
 > perf impact though; could you deploy it to a cluster with a large
 > number of replicas and gauge the impact on a beefy TSHeartbeat?

Thank you for the feedback!  I'll work on a couple of tests to cover this 
functionality and to gauge the impact of this change.

http://gerrit.cloudera.org:8080/#/c/14897/1/src/kudu/master/catalog_manager.cc
File src/kudu/master/catalog_manager.cc:

http://gerrit.cloudera.org:8080/#/c/14897/1/src/kudu/master/catalog_manager.cc@4282
PS1, Line 4282:         std::move(actions), 
FLAGS_consensus_max_batch_size_bytes);
> This seems rather low (1 MB). How does the consensus queue behave if this i
Yes, sxactly -- the default value for --consensus_max_batch_size_bytes is just 
1MB and it seems be a bit low.  However this is what used in the path of 
ConsensusUpdate(), so I tried to stay close to that here as well.  Yep, and a 
single ConsensusUpdate message might be arbitrarily large if that's the only 
message pushed to followers.

And yes: all these estimates are fuzzy, so suing --rpc_max_message_size doesn't 
seem save enough.  Maybe, using (rpc_max_message_size / 2) or (3 * 
rpc_max_message_size / 4) would be a safe threshold?  From the other side, why 
do we use  --consensus_max_batch_size_bytes at all then?

Is it a good time to revise the --consensus_max_batch_size_bytes vs 
--rpc_max_message_size approach even for the consensus messages itself?



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Gerrit-Project: kudu
Gerrit-Branch: master
Gerrit-MessageType: comment
Gerrit-Change-Id: I83e8ca4bc8db7cab8fee6b4a40f48adc8752e7c5
Gerrit-Change-Number: 14897
Gerrit-PatchSet: 1
Gerrit-Owner: Alexey Serbin <[email protected]>
Gerrit-Reviewer: Adar Dembo <[email protected]>
Gerrit-Reviewer: Alexey Serbin <[email protected]>
Gerrit-Reviewer: Kudu Jenkins (120)
Gerrit-Reviewer: Tidy Bot (241)
Gerrit-Comment-Date: Fri, 13 Dec 2019 00:24:31 +0000
Gerrit-HasComments: Yes

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