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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/12968633/HIVE-21686.3.patch {color:green}SUCCESS:{color} +1 due to 3 test(s) being added or modified. {color:green}SUCCESS:{color} +1 due to 16011 tests passed Test results: https://builds.apache.org/job/PreCommit-HIVE-Build/17202/testReport Console output: https://builds.apache.org/job/PreCommit-HIVE-Build/17202/console Test logs: http://104.198.109.242/logs/PreCommit-HIVE-Build-17202/ 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: 12968633 - 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.patch > > Time Spent: 3.5h > 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] -- This message was sent by Atlassian JIRA (v7.6.3#76005)