[MESOS-8950] Framework operations can make resources unallocatable

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Won't Fix
• Component/s: allocation, master
• Assignee: Unassigned
• Reporter: Benjamin Bannier
• Created: 24/May/18 13:23
• Updated: 13/Feb/19 19:30
• Resolved: 13/Feb/19 19:30

Description

The allocator does not offer cpus or mem resources smaller than certain, fixed sizes. For framework operations, we do not enforce the same minimum size constraints which can lead the resources becoming unavailable for any future allocations. This behavior seems most pronounced when a framework can register in many roles.

Example:

• A single multirole framework which can register in any role, e.g., in a certain role subhierarchy.
• Single agent with cpus:1.5*MIN_CPUS and mem:1.5*MIN_MEM.
• Framework is offered all resources and performs a RESERVE on cpus:0.5*MIN_CPUS. It then changes its role.
• Same framework behavior in next two offer cycles. All cpus are then reserved for different roles in unallocatable amounts.
• Last offer will be just for mem:1.5*MIN_MEM, framework reserves 0.6 of these to another role. This fragements the mem resources as well.
• No allocatable resources left in cluster.