xinbinhuang commented on a change in pull request #8084: Add Local and Sequential Executors to Doc URL: https://github.com/apache/airflow/pull/8084#discussion_r402784006
########## File path: airflow/executors/local_executor.py ########## @@ -16,31 +16,11 @@ # specific language governing permissions and limitations # under the License. """ -LocalExecutor runs tasks by spawning processes in a controlled fashion in different -modes. Given that BaseExecutor has the option to receive a `parallelism` parameter to -limit the number of process spawned, when this parameter is `0` the number of processes -that LocalExecutor can spawn is unlimited. - -The following strategies are implemented: -1. Unlimited Parallelism (self.parallelism == 0): In this strategy, LocalExecutor will -spawn a process every time `execute_async` is called, that is, every task submitted to the -LocalExecutor will be executed in its own process. Once the task is executed and the -result stored in the `result_queue`, the process terminates. There is no need for a -`task_queue` in this approach, since as soon as a task is received a new process will be -allocated to the task. Processes used in this strategy are of class LocalWorker. - -2. Limited Parallelism (self.parallelism > 0): In this strategy, the LocalExecutor spawns -the number of processes equal to the value of `self.parallelism` at `start` time, -using a `task_queue` to coordinate the ingestion of tasks and the work distribution among -the workers, which will take a task as soon as they are ready. During the lifecycle of -the LocalExecutor, the worker processes are running waiting for tasks, once the -LocalExecutor receives the call to shutdown the executor a poison token is sent to the -workers to terminate them. Processes used in this strategy are of class QueuedLocalWorker. - -Arguably, `SequentialExecutor` could be thought as a LocalExecutor with limited -parallelism of just 1 worker, i.e. `self.parallelism = 1`. -This option could lead to the unification of the executor implementations, running -locally, into just one `LocalExecutor` with multiple modes. +LocalExecutor + +.. seealso:: Review comment: Done! ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services
