Idea #9623
Updated by Tom Clegg over 7 years ago
In ContainerRequest#resolve, before creating a new Container, find out whether a Container already exists with * Exactly the same [command, cwd, environment, output_path, container_image, mounts, runtime_constraints] as the Container we're about to create * state in [Queued, Locked, Running, Complete] * (if state=Complete) exit_code==0 If multiple matching containers are found, take the first of: * The most recent container with state=Complete * The best A Running container (order by progress desc, started_at asc -- IOW, most likely to finish soonest) * The best A Queued or Locked container (order by priority desc, created_at asc -- IOW, most likely to start soonest) * The best Queued container (order by priority desc, created_at asc -- IOW, most likely to start soonest) In order to efficiently compare equality of serialized fields like mounts, runtime_constraints, and environment, we must: * Recursively sort hash keys before putting them in the database. This can be done in a Container before_save hook. * Recursively sort hash keys before using them in a query like "where mounts=?". This must be done during ContainerRequest#resolve. (The keys do not need to be sorted in the ContainerRequest's serialized attrs.) For now, we will *not* implement: * A mechanism allowing a client to skip re-use and force creation of a new container