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Gopal Vijayaraghavan commented on HIVE-23210: --------------------------------------------- {code} // Compute knownPending tasks. selfAndUpstream indicates task counts for current vertex and // it's parent hierarchy. selfAndUpstreamComplete indicates how many of these have completed. int knownPending1 = fri1.getNumSelfAndUpstreamTasks() - fri1.getNumSelfAndUpstreamCompletedTasks(); int knownPending2 = fri2.getNumSelfAndUpstreamTasks() - fri2.getNumSelfAndUpstreamCompletedTasks(); // longer the wait time for an attempt wrt to its start time, higher the priority it gets long waitTime1 = fri1.getCurrentAttemptStartTime() - fri1.getFirstAttemptStartTime(); long waitTime2 = fri2.getCurrentAttemptStartTime() - fri2.getFirstAttemptStartTime(); if (waitTime1 == 0 || waitTime2 == 0) { return knownPending1 - knownPending2; } {code} So here, for a vertex with 1 task, for the first attempt, it will return 0; It should return at least the FIFO order of getCurrentAttemptStartTime() > Fix shortestjobcomparator when jobs submitted have 1 task their vertices > ------------------------------------------------------------------------ > > Key: HIVE-23210 > URL: https://issues.apache.org/jira/browse/HIVE-23210 > Project: Hive > Issue Type: Improvement > Reporter: Rajesh Balamohan > Assignee: Panagiotis Garefalakis > Priority: Major > Attachments: TestShortestJobFirstComparator.java > > > In latency sensitive queries, lots of jobs can have vertices with 1 task. > Currently shortestjobcomparator does not work correctly and returns tasks in > random order. > [https://github.com/apache/hive/blob/master/llap-server/src/java/org/apache/hadoop/hive/llap/daemon/impl/comparator/ShortestJobFirstComparator.java#L51] > This causes delay in the job runtime. I will attach a simple test case > shortly. -- This message was sent by Atlassian Jira (v8.3.4#803005)