Containerizers are Mesos components responsible for launching containers. They own the containers launched for the tasks/executors, and are responsible for their isolation, resource management, and events (e.g., statistics).
--containerizers). If multiple containerizers (e.g., docker, mesos) are specified using the
--containerizersflag, then the composing containerizer will be used to create a containerizer.
TaskInfo, Mesos agent will use the default executor for the task (depending on the Containerizer the agent is using, it could be
mesos-docker-executor). TODO: Update this after MESOS-1718 is completed. After this change, master will be responsible for generating executor information.
Mesos currently supports the following containerizers:
Composing containerizer will compose the specified containerizers (using agent flag
--containerizers) and act like a single containerizer. This is an implementation of the
composite design pattern.
Docker containerizer manages containers using the docker engine provided in the docker package.
ContainerInfo::typeis set to DOCKER.
A) Mesos agent runs in a docker container
--docker_mesos_image. In this case, the value of flag
--docker_mesos_imageis assumed to be the docker image used to launch the Mesos agent.
mesos-docker-executoris launched in a docker container to execute the command via Docker CLI.
B) Mesos agent does not run in a docker container
mesos-docker-executorthen spawns a shell to execute the command via Docker CLI.
Mesos containerizer is the native Mesos containerizer. Mesos Containerizer will handle any executor/task that does not specify
Launcher is responsible for forking/destroying containers.
Starting from Mesos 1.1.0, nested container is supported. The Linux Launcher is responsible to fork the subprocess for the nested container with appropriate Linux namespaces being cloned. The following is the table for Linux namespaces that are supported for top level and nested containers.
*Note: For the top level container,
shared means that the container shares the namespace from the agent. For the nested container,
shared means that the nested container shares the namespace from its parent container.
Isolators are responsible for creating an environment for the containers where resources like cpu, network, storage and memory can be isolated from other containers.