[YARN-2297] Preemption can prevent progress in small queues

• Type: Sub-task
• Status: Open
• Priority: Critical
• Resolution: Unresolved
• Affects Version/s: 2.5.0
• Component/s: capacityscheduler
• Assignee: Wangda Tan
• Reporter: Tassapol Athiapinya
• Created: 16/Jul/14 00:10
• Updated: 19/Jul/14 14:54

Description

Preemption can cause hang issue in single-node cluster. Only AMs run. No task container can run.

queue configuration

Queue A/B has 1% and 99% respectively.
No max capacity.

scenario

Turn on preemption. Configure 1 NM with 4 GB of memory. Use only 2 apps. Use 1 user.
Submit app 1 to queue A. AM needs 2 GB. There is 1 task that needs 2 GB. Occupy entire cluster.
Submit app 2 to queue B. AM needs 2 GB. There are 3 tasks that need 2 GB each.
Instead of entire app 1 preempted, app 1 AM will stay. App 2 AM will launch. No task of either app can proceed.

commands

/usr/lib/hadoop/bin/hadoop jar /usr/lib/hadoop-mapreduce/hadoop-mapreduce-examples.jar randomtextwriter "-Dmapreduce.map.memory.mb=2000" "-Dyarn.app.mapreduce.am.command-opts=-Xmx1800M" "-Dmapreduce.randomtextwriter.bytespermap=2147483648" "-Dmapreduce.job.queuename=A" "-Dmapreduce.map.maxattempts=100" "-Dmapreduce.am.max-attempts=1" "-Dyarn.app.mapreduce.am.resource.mb=2000" "-Dmapreduce.map.java.opts=-Xmx1800M" "-Dmapreduce.randomtextwriter.mapsperhost=1" "-Dmapreduce.randomtextwriter.totalbytes=2147483648" dir1

/usr/lib/hadoop/bin/hadoop jar /usr/lib/hadoop-mapreduce/hadoop-mapreduce-client-jobclient-tests.jar sleep "-Dmapreduce.map.memory.mb=2000" "-Dyarn.app.mapreduce.am.command-opts=-Xmx1800M" "-Dmapreduce.job.queuename=B" "-Dmapreduce.map.maxattempts=100" "-Dmapreduce.am.max-attempts=1" "-Dyarn.app.mapreduce.am.resource.mb=2000" "-Dmapreduce.map.java.opts=-Xmx1800M" -m 1 -r 0 -mt 4000 -rt 0