I run "bin/run_server_task -t DevserverPushTask -v /root/chromeos-admin/server-management-lib/server_management_lib/configs/settings/devserver_variables_template.json".

The command completed immediately and pasted:

Existing virtualenv /root/chromeos-admin/bin/.venv is already up to date
INFO:root:Updating devservers...
INFO:root:Successfully update all lab devservers
INFO:root:Printing out task report.
{
  "sub_reports": [],
  "exception": null,
  "is_successful": true,
  "description": "Successfully update all lab devservers",
  "arguments_used": {
    "prod_master": "cautotest"
  },
  "task_name": "DevserverPushTask"
}

 
but looks like it's not actually updating the devservers chromite. for example, chromeos-test@chromeos4-devserver6 still runs the old chromite. 

shuqianz@, can you take a look? anything goes wrong in the command or in the server?