incubator-airflow git commit: Add pool upgrade issue description

[bo...@apache.org]

Repository: incubator-airflow
Updated Branches:
  refs/heads/master 61fb6a5e5 -> e63cb1fce


Add pool upgrade issue description


Project: http://git-wip-us.apache.org/repos/asf/incubator-airflow/repo
Commit: http://git-wip-us.apache.org/repos/asf/incubator-airflow/commit/e63cb1fc
Tree: http://git-wip-us.apache.org/repos/asf/incubator-airflow/tree/e63cb1fc
Diff: http://git-wip-us.apache.org/repos/asf/incubator-airflow/diff/e63cb1fc

Branch: refs/heads/master
Commit: e63cb1fced9517397b7db9e2849bf01fcca63902
Parents: 61fb6a5
Author: Bolke de Bruin <bo...@xs4all.nl>
Authored: Thu Feb 9 16:10:17 2017 +0100
Committer: Bolke de Bruin <bo...@xs4all.nl>
Committed: Thu Feb 9 16:10:17 2017 +0100

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 UPDATING.md | 6 ++++++
 1 file changed, 6 insertions(+)
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http://git-wip-us.apache.org/repos/asf/incubator-airflow/blob/e63cb1fc/UPDATING.md
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diff --git a/UPDATING.md b/UPDATING.md
index 337b711..b56aca8 100644
--- a/UPDATING.md
+++ b/UPDATING.md
@@ -14,6 +14,12 @@ Systemd unit files have been updated. If you use systemd please make sure to upd
 
 > Please note that the webserver does not detach properly, this will be fixed in a future version.
 
+### Tasks not starting although dependencies are met due to stricter pool checking
+Airflow 1.7.1 has issues with being able to over subscribe to a pool, ie. more slots could be used than were
+available. This is fixed in Airflow 1.8.0, but due to past issue jobs may fail to start although their
+dependencies are met after an upgrade. To workaround either temporarily increase the amount of slots above
+the the amount of queued tasks or use a new pool.
+
 ### Less forgiving scheduler on dynamic start_date
 Using a dynamic start_date (e.g. `start_date = datetime.now()`) is not considered a best practice. The 1.8.0 scheduler
 is less forgiving in this area. If you encounter DAGs not being scheduled you can try using a fixed start_date and