[YARN-5849] Automatically create YARN control group for pre-mounted cgroups

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.7.3, 3.0.0-alpha1, 3.0.0-alpha2
• Fix Version/s: 2.9.0, 3.0.0-alpha2
• Hadoop Flags: Reviewed
• Assignee: Miklos Szegedi
• Reporter: Miklos Szegedi
• Created: 07/Nov/16 21:29
• Updated: 12/Jan/17 01:37
• Resolved: 12/Jan/17 00:04

Description

Yarn can be launched with linux-container-executor.cgroups.mount set to false. It will search for the cgroup mount paths set up by the administrator parsing the /etc/mtab file. You can also specify resource.percentage-physical-cpu-limit to limit the CPU resources assigned to containers.
linux-container-executor.cgroups.hierarchy is the root of the settings of all YARN containers. If this is specified but not created YARN will fail at startup:
Caused by: java.io.FileNotFoundException: /cgroups/cpu/hadoop-yarn/cpu.cfs_period_us (Permission denied)
org.apache.hadoop.yarn.server.nodemanager.util.CgroupsLCEResourcesHandler.updateCgroup(CgroupsLCEResourcesHandler.java:263)

This JIRA is about automatically creating YARN control group in the case above. It reduces the cost of administration.