Hi Jongyoul, It depends on what you refer to as a "container".
In Mesos actually there are several concepts in play, tasks that is either a custom executor or a command, executors that are responsible for launching tasks, and containerizers that are responsible for creating the containers to launch executors and/or tasks. So if you are referring to an actual container that in mesos is either cgroups or docker, then depending on the implementation of the particular containerizer (Mesos or Docker or External, etc), a container can have multiple tasks or executors although currently all of them launches one container per executor. Executor itself can potentially launch multiple tasks that are running simultaneously as long as the executor is registered and referred to the same id by multiple tasks. In the slave object itself, it only tracks frameworks and executors, and when it doens't find it registered in memory it will ask the containerizer to launch it. Tim On Thu, Jan 1, 2015 at 11:01 AM, Nishant Suneja <[email protected]> wrote: > Hi Jongyoul > > Take a look at the slave/state.hpp file, and go through the hierarchy of > the state information starting from slave to task. > You will see that an executor state has a map of run states, which is > indexed by containerId. > It also has "latest" field to denote the current containerId which its > using. > > So, to answer your question, at any point of time, an executor should have > just one active container (which means one process on the system), > and that process's working directory would be identified by the "latest" > containerId field in the ExecutorState. > But, it can have multiple directories from the previous runs, each > identified by a unique containerId. > These directories would eventually be garbage collected. > > Nishant > > > > > > On Tue, Dec 30, 2014 at 6:12 PM, Jongyoul Lee <[email protected]> wrote: > >> Hi, dev >> >> I'm curious about the relationship between executor and container. Can any >> executor have multiple container? or have just one? In codes of slave.cpp, >> launchExecutor only can create container and is called only when the return >> value of getExecutor is null. Thus I think each executor can have one >> container only. Is it correct? If I'm wrong, please tell me correct >> procedure. >> >> Thanks in advance, >> JL >> >> -- >> 이종열, Jongyoul Lee, 李宗烈 >> http://madeng.net >>
