[MESOS-8905] Remove a redundant resource update for the executor launched as a Docker container

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: docker
• Assignee: Shubham Kumar
• Reporter: Qian Zhang
• Created: 11/May/18 02:21
• Updated: 13/May/18 16:50

Description

In `DockerContainerizerProcess::_launch` we have these codes:

Future<Containerizer::LaunchResult> DockerContainerizerProcess::_launch(
    const ContainerID& containerId,
    const ContainerConfig& containerConfig)
{
    ...
    .then(defer(self(), [=]() {
      return launchExecutorContainer(containerId, containerName);
    }))
    .then(defer(self(), [=](const Docker::Container& dockerContainer) {
      // Call update to set CPU/CFS/mem quotas at launch.
      // TODO(steveniemitz): Once the minimum docker version supported
      // is >= 1.7 this can be changed to pass --cpu-period and
      // --cpu-quota to the 'docker run' call in
      // launchExecutorContainer.
      return update(
          containerId, containerConfig.executor_info().resources(), true)
        .then([=]() {
          return Future<Docker::Container>(dockerContainer);
        });
    }))
    ...

With the fix to MESOS-6134, `launchExecutorContainer` will launch the executor as a Docker container and set its CPU quota accordingly, so we do not need the subsequent call to `update` to update the Docker container's resources again, actually it is already mentioned in the TODO above the call to `update`. So we should remove the call to `update` and also the TODO.