Hello Jean-Daniel Cryans,
I'd like you to do a code review. Please visit
http://gerrit.cloudera.org:8080/5531
to review the following change.
Change subject: spark: continue scanning after encountering empty batch
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spark: continue scanning after encountering empty batch
The Spark connector would previously stop scanning after the first empty
batch returned by a tablet server. The tablet server will not return an
empty batch when there are rows remaining in the tablet unless the scan
hits an internal timeout of 500ms[1]. This can only realistically happen
on large scans with highly selective predicates on data not in the block
cache. As a result this behavior only occurs with very large tables on
slow tablet server, which makes it very hard to test. No unit tests are
included with this patch, but the fix has been verified on a real
cluster exhibiting the issue.
[1]
https://github.com/apache/kudu/blob/2ed179a7a188b4748a43a829940764ab5dddbc1c/src/kudu/tserver/tablet_service.cc#L1670
Change-Id: I4fdb7836a27940cab674100da0ef0ea5e050bbdd
---
M java/kudu-spark/src/main/scala/org/apache/kudu/spark/kudu/KuduRDD.scala
1 file changed, 2 insertions(+), 2 deletions(-)
git pull ssh://gerrit.cloudera.org:29418/kudu refs/changes/31/5531/1
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Gerrit-MessageType: newchange
Gerrit-Change-Id: I4fdb7836a27940cab674100da0ef0ea5e050bbdd
Gerrit-PatchSet: 1
Gerrit-Project: kudu
Gerrit-Branch: master
Gerrit-Owner: Dan Burkert <[email protected]>
Gerrit-Reviewer: Jean-Daniel Cryans <[email protected]>
