Analyzing resource placement fragmentation for capacity planning

A distributed system, comprising:

• a plurality of resource hosts configured to implement a plurality of resources for the distributed system;
• a capacity manager implemented via one or more hardware processors and memory and configured to:
• determine one or more fragmentation measures that indicate unutilized capacity at the plurality of resource hosts that is incapable of hosting additional resources while satisfying one or more placement constraints for placing resources in the distributed system so that the one or more fragmentation measures represent stranded capacity of the distributed system;
• update, based at least in part on the one or more fragmentation measures, a capacity model for the distributed system to indicate an available capacity for placing additional resources at the distributed system;
• and
• compare a capacity threshold to the available capacity to determine whether to trigger an action to add additional capacity to the distributed system.

A method, comprising:

• performing, by one or more computing devices:
• determining, for a distributed system comprising a plurality of resource hosts configured to implement a plurality of resources, one or more fragmentation measures that indicate unutilized capacity at the plurality of resource hosts that is incapable of hosting additional resources while satisfying one or more placement constraints for placing resources in the distributed system so that the one or more fragmentation measures represent stranded capacity of the distributed system;
• updating, based at least in part on the one or more fragmentation measures, a capacity model for the distributed system to indicate an available capacity for placing additional resources at the distributed system;
• and
• comparing a capacity threshold to the available capacity to determine whether to trigger an action to add additional capacity to the distributed system.

One or more non-transitory computer-readable storage media storing program instructions that when executed on or across one or more processors cause the one or more processors to implement:

• determining, for a distributed system comprising a plurality of resource hosts configured to implement a plurality of resources, one or more fragmentation measures that indicate unutilized capacity that is incapable of hosting additional resources while satisfying one or more placement constraints for placing resources in the distributed system so that the one or more fragmentation measures represent stranded capacity of the distributed system;
• updating, based at least in part on the one or more fragmentation measures, a capacity model for the distributed system to indicate an available capacity for placing additional resources at the distributed system;
• and
• comparing a capacity threshold to the available capacity to determine whether to trigger an action to add additional capacity to the distributed system.