How to Customize your Service Resources
By default, docker services will use as much CPU or memory as they require. You may, however, wish to set a hard limit on memory, or the relative CPU shares used by a service. This can be accomplished with the
The default number of CPU shares given to a service is 1024. This is a relative number - if the service of container A has 1024 CPU shares, and the service of container B has 512 CPU shares, and both containers attempt to use 100% of the CPU, then container B will receive half of the total CPU time. This only applies when CPU-intensive tasks are running, as if one container is idle then the others can use the remaining CPU time.
The memory limit will apply to RAM usage, and SWAP usage. A valid entry is a positive number, followed by one of “b”, “k”, “m”, or “g”, with the minimum being “4m”.