Bikramjeet Vig has uploaded this change for review. ( 
http://gerrit.cloudera.org:8080/16385


Change subject: IMPALA-9792: Implement splitting kudu scan ranges for greater 
parallelism
......................................................................

IMPALA-9792: Implement splitting kudu scan ranges for greater
parallelism

This patch adds the ability to split kudu scan token via the provided
kudu java API. This helps increase parallelism during scanning
resulting in more efficient use with higher mt_dop. This however
comes at an added cost of an RPC to tablet server per partition so
it is only set by default for mt_dop > 1. A query option
"TARGETED_KUDU_SCAN_RANGE_LENGTH" has been added to set the scan
range length used in this implementation.

Limitation:
- The scan range length sent to kudu is just a hint and does not
  guarantee that the token will be split at that limit.
- A slow tablet server which can already slow down scanning during
  execution can now also potentially slow down planning.

Testing:
- Added e2e tests

Change-Id: Ia02fd94cc1d13c61bc6cb0765dd2cbe90e9a5ce8
---
M be/src/service/query-options-test.cc
M be/src/service/query-options.cc
M be/src/service/query-options.h
M common/thrift/ImpalaInternalService.thrift
M common/thrift/ImpalaService.thrift
M fe/src/main/java/org/apache/impala/planner/KuduScanNode.java
M tests/query_test/test_kudu.py
7 files changed, 109 insertions(+), 3 deletions(-)



  git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/85/16385/1
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Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-MessageType: newchange
Gerrit-Change-Id: Ia02fd94cc1d13c61bc6cb0765dd2cbe90e9a5ce8
Gerrit-Change-Number: 16385
Gerrit-PatchSet: 1
Gerrit-Owner: Bikramjeet Vig <[email protected]>

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