[jira] [Closed] (AIRFLOW-61) Corner case with deadlocked multiprocessing queues

["Jeremiah Lowin (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/AIRFLOW-61?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Jeremiah Lowin closed AIRFLOW-61.
---------------------------------
    Resolution: Fixed
      Assignee: Jeremiah Lowin

Merged in https://github.com/apache/incubator-airflow/pull/1473

[~criccomini]: Leaving the "fix version" at 1.7.1 for now

> Corner case with deadlocked multiprocessing queues
> --------------------------------------------------
>
>                 Key: AIRFLOW-61
>                 URL: https://issues.apache.org/jira/browse/AIRFLOW-61
>             Project: Apache Airflow
>          Issue Type: Bug
>          Components: scheduler
>    Affects Versions: Airflow 1.7.0
>            Reporter: Jeremiah Lowin
>            Assignee: Jeremiah Lowin
>             Fix For: Airflow 1.7.1
>
>
> I've never experienced this before, but it came up while testing this morning. Joining a process that puts items in a queue can apparently lead to deadlocks. This happens in the multiprocessing-enabled scheduler. 
> See for example: https://docs.python.org/3/library/multiprocessing.html#all-start-methods ("Joining processes that use queues") and related issues:
> http://stackoverflow.com/questions/31665328/python-3-multiprocessing-queue-deadlock-when-calling-join-before-the-queue-is-em
> http://stackoverflow.com/questions/31708646/process-join-and-queue-dont-work-with-large-numbers
> http://stackoverflow.com/questions/19071529/python-multiprocessing-125-list-never-finishes



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)