docker
/
docs
mirror of https://github.com/docker/docs.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

add placement pref note about null labels (#5250)

This commit is contained in:
Bret Fisher 2017-11-10 17:05:34 -05:00 committed by Misty Stanley-Jones
parent 8f87edefb3
commit 06e64aaefe
1 changed files with 10 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
engine/swarm/services.md
View File

@ -646,6 +646,16 @@ $ docker service create \
redis:3.0.6 redis:3.0.6
``` ```
> Missing or null labels
>
> Nodes which are missing the label used to spread will still receive
> task assignments. As a group, these nodes will receive tasks in equal
> proportion to any of the other groups identified by a specific label
> value. In a sense, a missing label is the same as having the label with
> a null value attached to it. If the service should **only** run on
> nodes with the label being used for the the spread preference, the
> preference should be combined with a constraint.
You can specify multiple placement preferences, and they are processed in the You can specify multiple placement preferences, and they are processed in the
order they are encountered. The following example sets up a service with order they are encountered. The following example sets up a service with
multiple placement preferences. Tasks are spread first over the various multiple placement preferences. Tasks are spread first over the various