[YARN-8112] Fix min cardinality check for same source and target tags in intra-app constraints

• Type: Sub-task
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: resourcemanager
• Assignee: Konstantinos Karanasos
• Reporter: Weiwei Yang
• Created: 03/Apr/18 07:59
• Updated: 03/Feb/19 03:24

Description

The min cardinality constraint (min cardinality = k) ensures that a container is placed at a node that has already k occurrences of the target tag. For example, a constraint zk=3,CARDINALITY,NODE,hb,2,10 will place each of the three zk containers on a node with at least 2 hb instances (and no more than 10 for the max cardinality).

Affinity constraints is a special case of this where min cardinality is 1.

Currently we do not support min cardinality when the source and the target of the constraint are the same in an intra-app constraint.

Therefore, zk=3,CARDINALITY,NODE,zk,2,10 is not supported, and neither is zk=3,IN,NODE,zk.

This Jira will address this problem by placing the first k containers on the same node (or any other specified scope, e.g., rack), so that min cardinality can be met when placing the subsequent containers with the same tag.