The placement Strategy to apply to the task. See Placement Strategies for more details.
If using binpack or spread you must specify Placement Strategy Field.
binpack
Place tasks based on the least available amount of CPU or memory. This minimizes the number of instances in use.

random
Place tasks randomly.

spread
Place tasks evenly based on the specified value. Accepted values are attribute key-value pairs, instanceId, or host. Service tasks are spread based on the tasks from that service