[YARN-8206] Sending a kill does not immediately kill docker containers

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.2.0, 3.1.1
• Labels: Docker
• Hadoop Flags: Reviewed
• Assignee: Eric Badger
• Reporter: Eric Badger
• Created: 25/Apr/18 19:54
• Updated: 22/May/18 18:20
• Resolved: 22/May/18 14:51

Description

        if (ContainerExecutor.Signal.KILL.equals(signal)
            || ContainerExecutor.Signal.TERM.equals(signal)) {
          handleContainerStop(containerId, env);

Currently in the code, we are handling both SIGKILL and SIGTERM as equivalent for docker containers. However, they should actually be separate. When YARN sends a SIGKILL to a process, it means for it to die immediately and not sit around waiting for anything. This ensures an immediate reclamation of resources. Additionally, if a SIGTERM is sent before the SIGKILL, the task might not handle the signal correctly, and will then end up as a failed task instead of a killed task. This is especially bad for preemption.

Issue Links

• is related to: YARN-8259 Revisit liveliness checks for Docker containers