memoryReservation

The soft limit (in MiB) of memory to reserve for the container. When system memory is under heavy contention, Docker attempts to keep the container memory to this soft limit. However, your container can consume more memory when it needs to, up to either the hard limit specified with the `memory` parameter (if applicable), or all of the available memory on the container instance, whichever comes first. This parameter maps to `MemoryReservation` in the docker container create command and the `--memory-reservation` option to docker run. If a task-level memory value is not specified, you must specify a non-zero integer for one or both of `memory` or `memoryReservation` in a container definition. If you specify both, `memory` must be greater than `memoryReservation`. If you specify `memoryReservation`, then that value is subtracted from the available memory resources for the container instance where the container is placed. Otherwise, the value of `memory` is used. For example, if your container normally uses 128 MiB of memory, but occasionally bursts to 256 MiB of memory for short periods of time, you can set a `memoryReservation` of 128 MiB, and a `memory` hard limit of 300 MiB. This configuration would allow the container to only reserve 128 MiB of memory from the remaining resources on the container instance, but also allow the container to consume more memory resources when needed. The Docker 20.10.0 or later daemon reserves a minimum of 6 MiB of memory for a container. So, don't specify less than 6 MiB of memory for your containers. The Docker 19.03.13-ce or earlier daemon reserves a minimum of 4 MiB of memory for a container. So, don't specify less than 4 MiB of memory for your containers.