ashb commented on code in PR #43893: URL: https://github.com/apache/airflow/pull/43893#discussion_r1837974486
########## task_sdk/src/airflow/sdk/execution_time/comms.py: ########## @@ -0,0 +1,103 @@ +# +# Licensed to the Apache Software Foundation (ASF) under one +# or more contributor license agreements. See the NOTICE file +# distributed with this work for additional information +# regarding copyright ownership. The ASF licenses this file +# to you under the Apache License, Version 2.0 (the +# "License"); you may not use this file except in compliance +# with the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, +# software distributed under the License is distributed on an +# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +# KIND, either express or implied. See the License for the +# specific language governing permissions and limitations +# under the License. +r""" +Communication protocol between the Supervisor and the task process +================================================================== + +* All communication is done over stdout/stdin in the form of "JSON lines" (each + message is a single JSON document terminated by `\n` character) +* Messages from the subprocess are all log messages and are sent directly to the log +* No messages are sent to task process except in response to a request. (This is because the task process will + be running user's code, so we can't read from stdin until we enter our code, such as when requesting an XCom + value etc.) Review Comment: the Supervisor _could_ be written to be async, but the task subprocess itself can't be async right now as task code is sync. (We'll need to do something async around the triggerer) The Supervisor is a akin to an HTTP proxy for this traffic, but also has other responsibilities (such as watching the process for exting etc.) -- 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. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
