VladaZakharova opened a new pull request, #32365:
URL: https://github.com/apache/airflow/pull/32365

   This PR fixes https://github.com/apache/airflow/issues/29258
   
   The problem was caused by multiple processes updating metadata of the 
Compute Engine instance when running in parallel: methods 
_authorize_compute_engine_instance_metadata() and import_ssh_public_key() are 
used to upload metadata and import ssh keys. Both of them included making API 
requests to update information inside the instance. When making such requests 
in parallel all the processes were updating the same data simultaneously, that 
caused those problems listed in the issue.
   
   The solution here is to use some kind of lock to prevent execution of 
critical part of the code by several processes at one time. As the Composer is 
a distributed system, all the processes are running separately, making 
connection between them hard.
   As the solution in this case i have implemented a logic of creation separate 
GCS bucket that will hold a file that will be used as a lock for the processes: 
if the file exists and there is a string inside it - the lock is acquired. 
After the execution is finished, the lock will be released, so next process 
could take this lock next. The last process running will delete the bucket.
   
   Note: when establishing connection using os_login, make sure that you have 
enabled such option for your instance in instance keys and that all of the 
connections you are trying to establish use the same value for the parameter: 
once you have enabled os_login for your instance, it will wait the exact type 
of keys to authenticate correctly. There is no option to mix different types of 
authentication for one instance.
   <!--
    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.
    -->
   
   <!--
   Thank you for contributing! Please make sure that your code changes
   are covered with tests. And in case of new features or big changes
   remember to adjust the documentation.
   
   Feel free to ping committers for the review!
   
   In case of an existing issue, reference it using one of the following:
   
   closes: #ISSUE
   related: #ISSUE
   
   How to write a good git commit message:
   http://chris.beams.io/posts/git-commit/
   -->
   
   ---
   **^ Add meaningful description above**
   
   Read the **[Pull Request 
Guidelines](https://github.com/apache/airflow/blob/main/CONTRIBUTING.rst#pull-request-guidelines)**
 for more information.
   In case of fundamental code changes, an Airflow Improvement Proposal 
([AIP](https://cwiki.apache.org/confluence/display/AIRFLOW/Airflow+Improvement+Proposals))
 is needed.
   In case of a new dependency, check compliance with the [ASF 3rd Party 
License Policy](https://www.apache.org/legal/resolved.html#category-x).
   In case of backwards incompatible changes please leave a note in a 
newsfragment file, named `{pr_number}.significant.rst` or 
`{issue_number}.significant.rst`, in 
[newsfragments](https://github.com/apache/airflow/tree/main/newsfragments).
   


-- 
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]

Reply via email to