Dan Burkert has posted comments on this change. ( 
http://gerrit.cloudera.org:8080/8823 )

Change subject: KUDU-1704: add c++ client support for READ_YOUR_WRITES mode
......................................................................


Patch Set 8:

(3 comments)

http://gerrit.cloudera.org:8080/#/c/8823/8/src/kudu/client/client-internal.h
File src/kudu/client/client-internal.h:

http://gerrit.cloudera.org:8080/#/c/8823/8/src/kudu/client/client-internal.h@197
PS8, Line 197:   uint64_t GetMaxObservedTimestamp() const;
Please add docs to these, since it's not obvious anymore, e.g. what's the 
difference between GetLatestObserved and GetMaxObserverd


http://gerrit.cloudera.org:8080/#/c/8823/8/src/kudu/client/client-internal.h@278
PS8, Line 278:   AtomicInt<uint64_t> max_observed_timestamp_;
I didn't expect an additional field on the client here, instead I though the 
scanner would get a new field 'propagated_timestamp' that would be used in RYW 
scans.  Instead of using the client's latest_observed_timestamp() as the 
propagated timestamp it would use that field.

As implemented here, isn't there interactions between two concurrently opened 
RYW scanners?


http://gerrit.cloudera.org:8080/#/c/8823/8/src/kudu/client/client.h
File src/kudu/client/client.h:

http://gerrit.cloudera.org:8080/#/c/8823/8/src/kudu/client/client.h@1740
PS8, Line 1740:     /// When @c READ_YOUR_WRITES is specified, the server will 
pick a snapshot timestamp
We should consider 'dumbing down' these docs considerably.  For instance, the 
client really shouldn't need to know anything about timestamps or in-flight 
transactions to use or pick this scan mode.  I think it's fine to get into this 
level of specificity on the READ_YOUR_WRITES docs in the .proto, since that's 
internal, however these docs have a different audience.  I'd try and re-focus 
this doc on the characteristics of the scan from the perspective of the client 
application.  I'd also consider asking Alexandra to do do a pass on this.



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Gerrit-Project: kudu
Gerrit-Branch: master
Gerrit-MessageType: comment
Gerrit-Change-Id: I34214245a78aed172a28fbdb395ff5bccd0fc0e1
Gerrit-Change-Number: 8823
Gerrit-PatchSet: 8
Gerrit-Owner: Hao Hao <[email protected]>
Gerrit-Reviewer: Dan Burkert <[email protected]>
Gerrit-Reviewer: David Ribeiro Alves <[email protected]>
Gerrit-Reviewer: Hao Hao <[email protected]>
Gerrit-Reviewer: Kudu Jenkins
Gerrit-Comment-Date: Fri, 16 Feb 2018 19:36:02 +0000
Gerrit-HasComments: Yes

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