Dan Hecht has posted comments on this change.

Change subject: IMPALA-5147: Add the ability to exclude hosts from query 
execution
......................................................................


Patch Set 1:

(1 comment)

http://gerrit.cloudera.org:8080/#/c/6628/1/be/src/scheduling/scheduler.cc
File be/src/scheduling/scheduler.cc:

Line 207:       current_membership_.insert(make_pair(item.key, be_desc));
> Thanks for the clarification. This patch modified the /backends webpage to 
I see, so you're saying that the "impala-membership" topic does contain all 
nodes of the cluster and their is_executor/is_coordinator bits. Okay, I missed 
that this callback doesn't do the topic update -- that's handled by the one in 
impala-server.cc.

This code is even more confusing now because the terminology is not clear. I 
think we need to do some renaming to make it easier to understand this code. 
For example, "current_membership_" is misleading now. It'd be better to rename 
that as "current_executors_" or similar.

Also, the terminology "backend" seems confusing (or at least could use 
clarifications).  e.g. a coordinator but non-executor is still considered a 
"backend" which seems weird.  I guess in the code we are saying "backend" is 
synonymous with "impalad"? (I think it would be too much to rename 
TBackendDescriptor right now, but I think we should consider doing that 
independently. The comment in the thrift file refers to the "backend topic", 
but the topic is called "impala-membership", so maybe this is historical naming)


-- 
To view, visit http://gerrit.cloudera.org:8080/6628
To unsubscribe, visit http://gerrit.cloudera.org:8080/settings

Gerrit-MessageType: comment
Gerrit-Change-Id: I5d2ff7f341c9d2b0649e4d14561077e166ad7c4d
Gerrit-PatchSet: 1
Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-Owner: Dimitris Tsirogiannis <[email protected]>
Gerrit-Reviewer: Dan Hecht <[email protected]>
Gerrit-Reviewer: Dimitris Tsirogiannis <[email protected]>
Gerrit-Reviewer: Lars Volker <[email protected]>
Gerrit-HasComments: Yes

Reply via email to