Hello Kurt Deschler, Wenzhe Zhou, Impala Public Jenkins,
I'd like you to reexamine a change. Please visit
http://gerrit.cloudera.org:8080/20024
to look at the new patch set (#6).
Change subject: IMPALA-12192: Fix scaling bug in scan fragment
......................................................................
IMPALA-12192: Fix scaling bug in scan fragment
IMPALA-12091 has a bug where scan fragment parallelism will always be
limited solely by the ScanNode cost. If ScanNode is colocated with other
query node operator that have higher processing cost, Planner will not
scale it up beyond what is allowed by the ScanNode cost.
This patch fix the problem in two aspect. First is to allow scan
fragment scale up higher as long as it is within total fragment cost and
number of effective scan ranges. Second is to add missing Math.max() in
CostingSegment.java that cause lower fragment parallelism even when the
total fragment cost is high.
This patch also fix "max-parallelism" value in explain string and make a
constant in ScanNode.rowMaterializationCost() into a backend flag named
scan_range_cost_factor for experimental purpose.
Testing:
- Manually run TPCDS Q84 over tpcds10_parquet and confirm that the
leftmost scan fragment parallelism is raised from 12 (before patch) to
18 (after patch).
- Add test in PlannerTest.testProcessingCost that reproduce the issue.
- Update compute stats test in test_executor_groups.py to maintain test
assertion.
- Pass core tests.
Change-Id: I7010f6c3bc48ae3f74e8db98a83f645b6c157226
---
M be/src/util/backend-gflag-util.cc
M common/thrift/BackendGflags.thrift
M fe/src/main/java/org/apache/impala/planner/CostingSegment.java
M fe/src/main/java/org/apache/impala/planner/DistributedPlanner.java
M fe/src/main/java/org/apache/impala/planner/HBaseScanNode.java
M fe/src/main/java/org/apache/impala/planner/HdfsScanNode.java
M fe/src/main/java/org/apache/impala/planner/KuduScanNode.java
M fe/src/main/java/org/apache/impala/planner/PlanFragment.java
M fe/src/main/java/org/apache/impala/planner/ScanNode.java
M fe/src/main/java/org/apache/impala/service/BackendConfig.java
M
testdata/workloads/functional-planner/queries/PlannerTest/tpcds-processing-cost.test
M tests/custom_cluster/test_executor_groups.py
12 files changed, 277 insertions(+), 151 deletions(-)
git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/24/20024/6
--
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Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-MessageType: newpatchset
Gerrit-Change-Id: I7010f6c3bc48ae3f74e8db98a83f645b6c157226
Gerrit-Change-Number: 20024
Gerrit-PatchSet: 6
Gerrit-Owner: Riza Suminto <riza.sumi...@cloudera.com>
Gerrit-Reviewer: Impala Public Jenkins <impala-public-jenk...@cloudera.com>
Gerrit-Reviewer: Kurt Deschler <kdesc...@cloudera.com>
Gerrit-Reviewer: Riza Suminto <riza.sumi...@cloudera.com>
Gerrit-Reviewer: Wenzhe Zhou <wz...@cloudera.com>
