Matthew Jacobs has posted comments on this change.

Change subject: IMPALA-5644,IMPALA-5810: Min reservation improvements
......................................................................


Patch Set 4:

(4 comments)

http://gerrit.cloudera.org:8080/#/c/7678/5/be/src/runtime/bufferpool/reservation-util.h
File be/src/runtime/bufferpool/reservation-util.h:

PS5, Line 32:  allocated to buffer reservations,
> After thinking about these variables more, this paragraph doesn't seem righ
I think it's the latter.

Maybe it'd be more clear if the first sentence was changed to:

The fraction of the query mem limit that is used as the maximum buffer 
reservation limit. It is expected that memory not accounted by buffer 
reservation trackers stays within (1 - RESERVATION_MEM_FRACTION).

I think the part of the text that you highlighted is just explaining the 
motivation for having a high value. What do you/Tim think?


PS5, Line 36: 
            :   /// The limit on reservations is co
> I don't follow that. we don't use buffer reservations for those yet.
I think this is providing examples of things that use the memory that is left 
after buffer reservations. I agree that depending on how you read it, it could 
be misleading. I can reword this to try to be more clear.

I incorporated this text from Tim's change to reduce 
RESERVATION_MEM_MIN_REMAINING, so it'd be good for him to comment as well.

Tim, is there any comment anywhere else about the 'classes' of memory already?


http://gerrit.cloudera.org:8080/#/c/7678/4/be/src/scheduling/admission-controller.cc
File be/src/scheduling/admission-controller.cc:

Line 125:     "more information.";
> I think we should soon make it so you can't disable admission control. Not 
Ok, I filed IMPALA-5814 for that.


PS4, Line 429: GetBufferReservationLimitFromMemLimit
> I missed that. But should line 425 be an else-if then?
This was actually my intention originally, and that's why I asked the question 
that I did in query-state.cc. I think it makes sense to apply both limits, but 
if we won't do that in query-state.cc then I'll make this code match.


-- 
To view, visit http://gerrit.cloudera.org:8080/7678
To unsubscribe, visit http://gerrit.cloudera.org:8080/settings

Gerrit-MessageType: comment
Gerrit-Change-Id: Iabe87ce8f460356cfe4d1be4d7092c5900f9d79b
Gerrit-PatchSet: 4
Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-Owner: Matthew Jacobs <[email protected]>
Gerrit-Reviewer: Dan Hecht <[email protected]>
Gerrit-Reviewer: Matthew Jacobs <[email protected]>
Gerrit-Reviewer: Tim Armstrong <[email protected]>
Gerrit-HasComments: Yes

Reply via email to