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https://issues.apache.org/jira/browse/HIVE-21686?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16839574#comment-16839574
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Hive QA commented on HIVE-21686:
--------------------------------
Here are the results of testing the latest attachment:
https://issues.apache.org/jira/secure/attachment/12968681/HIVE-21686.5.patch
{color:green}SUCCESS:{color} +1 due to 3 test(s) being added or modified.
{color:green}SUCCESS:{color} +1 due to 16012 tests passed
Test results:
https://builds.apache.org/job/PreCommit-HIVE-Build/17207/testReport
Console output: https://builds.apache.org/job/PreCommit-HIVE-Build/17207/console
Test logs: http://104.198.109.242/logs/PreCommit-HIVE-Build-17207/
Messages:
{noformat}
Executing org.apache.hive.ptest.execution.TestCheckPhase
Executing org.apache.hive.ptest.execution.PrepPhase
Executing org.apache.hive.ptest.execution.YetusPhase
Executing org.apache.hive.ptest.execution.ExecutionPhase
Executing org.apache.hive.ptest.execution.ReportingPhase
{noformat}
This message is automatically generated.
ATTACHMENT ID: 12968681 - PreCommit-HIVE-Build
> Brute Force eviction can lead to a random uncontrolled eviction pattern.
> ------------------------------------------------------------------------
>
> Key: HIVE-21686
> URL: https://issues.apache.org/jira/browse/HIVE-21686
> Project: Hive
> Issue Type: Bug
> Reporter: slim bouguerra
> Assignee: slim bouguerra
> Priority: Major
> Labels: pull-request-available
> Attachments: Cache_hitrate_improvement.csv, HIVE-21686.2.patch,
> HIVE-21686.3.patch, HIVE-21686.4.patch, HIVE-21686.5.patch, HIVE-21686.patch
>
> Time Spent: 4h
> Remaining Estimate: 0h
>
> Current logic used by brute force eviction can lead to a perpetual random
> eviction pattern.
> For instance if the cache build a small pocket of free memory where the total
> size is greater than incoming allocation request, the allocator will randomly
> evict block that fits a particular size.
> This can happen over and over therefore all the eviction will be random.
> In Addition this random eviction will lead a leak in the linked list
> maintained by the policy since it does not know anymore about what is evicted
> and what not.
> The improvement of this patch is very substantial to TPC-DS benchmark. I
> have tested it with 10TB scale 9 llap nodes and 32GB cache size per node.
> The patch has showed very noticeable difference in the Hit rate for raw
> number [^Cache_hitrate_improvement.csv]
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