Hello Alex Behm, Dan Hecht,
I'd like you to reexamine a change. Please visit
http://gerrit.cloudera.org:8080/7739
to look at the new patch set (#5).
Change subject: IMPALA-5713: always reserve memory for preaggs
......................................................................
IMPALA-5713: always reserve memory for preaggs
Before this change the preaggregation was frequently disabled when
running under some memory pressure, e.g. if the aggregation is at the
end of a pipeline of joins and those joins eat up all the memory.
This can result in huge performance degradation since all rows must then
be sent over the network.
This change always reserves 16 * (buffer size + 64kb) bytes per
preaggregation so that it is always able to build some hash tables and
reduce the input somewhat.
This has two parts:
* Changing the frontend reservation calculation
* Removing dead code in the backend that handled the case when the
initial partitions and hash tables could not be allocated.
Testing:
Passes exhaustive tests.
Change-Id: I2b544f9ec1a906719e2bbb074743926b95a3a573
---
M be/src/exec/partitioned-aggregation-node-ir.cc
M be/src/exec/partitioned-aggregation-node.cc
M be/src/exec/partitioned-aggregation-node.h
M fe/src/main/java/org/apache/impala/planner/AggregationNode.java
M testdata/workloads/functional-planner/queries/PlannerTest/max-row-size.test
M
testdata/workloads/functional-planner/queries/PlannerTest/mt-dop-validation.test
M
testdata/workloads/functional-planner/queries/PlannerTest/resource-requirements.test
M
testdata/workloads/functional-planner/queries/PlannerTest/spillable-buffer-sizing.test
M testdata/workloads/functional-query/queries/QueryTest/spilling-aggs.test
9 files changed, 108 insertions(+), 119 deletions(-)
git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/39/7739/5
--
To view, visit http://gerrit.cloudera.org:8080/7739
To unsubscribe, visit http://gerrit.cloudera.org:8080/settings
Gerrit-MessageType: newpatchset
Gerrit-Change-Id: I2b544f9ec1a906719e2bbb074743926b95a3a573
Gerrit-PatchSet: 5
Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-Owner: Tim Armstrong <[email protected]>
Gerrit-Reviewer: Alex Behm <[email protected]>
Gerrit-Reviewer: Dan Hecht <[email protected]>
Gerrit-Reviewer: Mostafa Mokhtar <[email protected]>
Gerrit-Reviewer: Tim Armstrong <[email protected]>
