--- title: Swarm task states description: Learn about tasks that are scheduled on your swarm. keywords: swarm, task, service redirect_from: - /datacenter/ucp/2.2/guides/admin/monitor-and-troubleshoot/troubleshoot-task-state/ --- Docker lets you create services, which can start tasks. A service is a description of a desired state, and a task does the work. Work is scheduled on swarm nodes in this sequence: 1. Create a service by using `docker service create` or the UCP web UI or CLI. 2. The request goes to a Docker manager node. 3. The Docker manager node schedules the service to run on particular nodes. 4. Each service can start multiple tasks. 5. Each task has a life cycle, with states like `NEW`, `PENDING`, and `COMPLETE`. Tasks are execution units that run once to completion. When a task stops, it isn't executed again, but a new task may take its place. Tasks advance through a number of states until they complete or fail. Tasks are initialized in the `NEW` state. The task progresses forward through a number of states, and its state doesn't go backward. For example, a task never goes from `COMPLETE` to `RUNNING`. Tasks go through the states in the following order: | Task state | Description | | ----------- | ----------------------------------------------------------------------------------------------------------- | | `NEW` | The task was initialized. | | `PENDING` | Resources for the task were allocated. | | `ASSIGNED` | Docker assigned the task to nodes. | | `ACCEPTED` | The task was accepted by a worker node. If a worker node rejects the task, the state changes to `REJECTED`. | | `PREPARING` | Docker is preparing the task. | | `STARTING` | Docker is starting the task. | | `RUNNING` | The task is executing. | | `COMPLETE` | The task exited without an error code. | | `FAILED` | The task exited with an error code. | | `SHUTDOWN` | Docker requested the task to shut down. | | `REJECTED` | The worker node rejected the task. | | `ORPHANED` | The node was down for too long. | | `REMOVE` | The task is not terminal but the associated service was removed or scaled down. | ## View task state Run `docker service ps ` to get the state of a task. The `CURRENT STATE` field shows the task's state and how long it's been there. ```bash $ docker service ps webserver ID NAME IMAGE NODE DESIRED STATE CURRENT STATE ERROR PORTS owsz0yp6z375 webserver.1 nginx UbuntuVM Running Running 44 seconds ago j91iahr8s74p \_ webserver.1 nginx UbuntuVM Shutdown Failed 50 seconds ago "No such container: webserver.…" 7dyaszg13mw2 \_ webserver.1 nginx UbuntuVM Shutdown Failed 5 hours ago "No such container: webserver.…" ``` ## Where to go next - [Learn about swarm tasks](https://github.com/docker/swarmkit/blob/master/design/task_model.md)