Auto Restart#
In daily operations, you may want to automatically restart the lab when some codes are changed.
AlabOS provides a convinient way to do this by using the auto_restart configuration.
To do so, just add the following line to your AlabOS configuration yaml file:
[general]
...
auto_refresh = true
By default, this feature is disabled. When enabled, AlabOS will monitor the source code files and automatically restart the lab when any changes are detected.
How It Works#
Main AlabOS process (Device and Task Manager): When there is a change in the device or task definition, the device and task manager will be re-imported. It is a process with the following steps:
Task manager will stop to launch new tasks.
Resource manager will stop to allocate new resources.
Device manager will try to pause all the devices.
Wait for all the tasks are NOT in RUNNING state (no communication with the devices).
All the devices will be disconnected.
Device and task manager will be re-imported.
Connect to the devices again.
Device manager will try to resume all the devices.
Resource manager will resume to allocate new resources.
Task manager will resume to launch new tasks.
Task Actor: Task actor is the function that actually runs the task. At the beginning of each task process,
the device and task definition will be re-imported. This means that any changes made to the task definition
or device code will be reflected in the task execution. If auto_refresh is not enabled or missing in the configuration,
the task actor will not be re-imported, and any changes made to the task definition or device
code will not be reflected in the task execution.
Note that the change will be reflected in the newly launched tasks right away, at the importing time. But for the device and task managers, it will check the file modification time every 30 s. This usually will not be a problem as the new task launching should typically take a while before it starts to send commands to the devices.
Limitations#
The auto_refresh feature has some limitations:
It only works for Python source code files. Changes to other types of files, such as configuration files or data files, will not trigger a restart.
External libraries or dependencies that are not part of the AlabOS codebase will not be monitored for changes. If you modify such libraries, you will need to manually restart the lab.
New devices and tasks: If you add new devices or tasks, you will need to manually restart the lab or there may be some unexpected behaviors.
For the tasks that are already running, the changes will not be reflected until the task is restarted. This means that if you change the device or task definition, the running tasks will continue to use the old definitions.