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https://issues.apache.org/jira/browse/HBASE-22346?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16837004#comment-16837004
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Hudson commented on HBASE-22346:
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Results for branch HBASE-22346
[build #4 on
builds.a.o|https://builds.apache.org/job/HBase%20Nightly/job/HBASE-22346/4/]:
(x) *{color:red}-1 overall{color}*
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details (if available):
(x) {color:red}-1 general checks{color}
-- For more information [see general
report|https://builds.apache.org/job/HBase%20Nightly/job/HBASE-22346/4//General_Nightly_Build_Report/]
(x) {color:red}-1 jdk8 hadoop2 checks{color}
-- For more information [see jdk8 (hadoop2)
report|https://builds.apache.org/job/HBase%20Nightly/job/HBASE-22346/4//JDK8_Nightly_Build_Report_(Hadoop2)/]
(x) {color:red}-1 jdk8 hadoop3 checks{color}
-- For more information [see jdk8 (hadoop3)
report|https://builds.apache.org/job/HBase%20Nightly/job/HBASE-22346/4//JDK8_Nightly_Build_Report_(Hadoop3)/]
(/) {color:green}+1 source release artifact{color}
-- See build output for details.
(/) {color:green}+1 client integration test{color}
> scanner priorities/deadline units are invalid for non-huge scanners
> -------------------------------------------------------------------
>
> Key: HBASE-22346
> URL: https://issues.apache.org/jira/browse/HBASE-22346
> Project: HBase
> Issue Type: Bug
> Reporter: Sergey Shelukhin
> Assignee: Sergey Shelukhin
> Priority: Major
> Attachments: HBASE-22346.01.patch, HBASE-22346.patch
>
>
> I was looking at using the priority (deadline) queue for scanner requests;
> what I see is that AnnotationReadingPriorityFunction, the only impl of the
> deadline function available, implements getDeadline as sqrt of the number of
> next() calls, from HBASE-10993.
> However, CallPriorityComparator.compare, its only caller, adds that
> "deadline" value to the callA.getReceiveTime() in milliseconds...
> That results in some sort of a meaningless value that I assume only make
> sense "by coincidence" for telling apart broad and specific classes of
> scanners... in practice next calls must be in the 1000s before it becomes
> meaningful vs small differences in ReceivedTime
> When there's contention from many scanners, e.g. small scanners for meta, or
> just users creating tons of scanners to the point where requests queue up,
> the actual deadline is not accounted for and the priority function itself is
> meaningless... In fact as queueing increases, it becomes worse because
> receivedtime differences grow.
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