github.com/kobeld/docker@v1.12.0-rc1/docs/swarm/swarm-tutorial/scale-service.md (about)

     1  <!--[metadata]>
     2  +++
     3  title = "Scale the service"
     4  description = "Scale the service running in the Swarm"
     5  keywords = ["tutorial, cluster management, swarm, scale"]
     6  [menu.main]
     7  identifier="swarm-tutorial-scale-service"
     8  parent="swarm-tutorial"
     9  weight=18
    10  advisory = "rc"
    11  +++
    12  <![end-metadata]-->
    13  
    14  # Scale the service in the Swarm
    15  
    16  Once you have [deployed a service](deploy-service.md) to a Swarm, you are ready
    17  to use the Docker CLI to scale the number of service tasks in
    18  the Swarm.
    19  
    20  1. If you haven't already, open a terminal and ssh into the machine where you
    21  run your manager node. For example, the tutorial uses a machine named
    22  `manager1`.
    23  
    24  2. Run the following command to change the desired state of the
    25  service runing in the Swarm:
    26  
    27      ```bash
    28      $ docker service update --replicas <NUMBER-OF-TASKS> <SERVICE-ID>
    29      ```
    30  
    31      The `--replicas` flag indicates the number of tasks you want in the new
    32      desired state. For example:
    33  
    34      ```bash
    35      $ docker service update --replicas 5 helloworld
    36      helloworld
    37      ```
    38  
    39  3. Run `docker service tasks <SERVICE-ID>` to see the updated task list:
    40  
    41      ```
    42      $ docker service tasks helloworld
    43  
    44      ID                         NAME          SERVICE     IMAGE   DESIRED STATE  LAST STATE          NODE
    45      1n6wif51j0w840udalgw6hphg  helloworld.1  helloworld  alpine  RUNNING        RUNNING 2 minutes   manager1
    46      dfhsosk00wxfb7j0cazp3fmhy  helloworld.2  helloworld  alpine  RUNNING        RUNNING 15 seconds  worker2
    47      6cbedbeywo076zn54fnwc667a  helloworld.3  helloworld  alpine  RUNNING        RUNNING 15 seconds  worker1
    48      7w80cafrry7asls96lm2tmwkz  helloworld.4  helloworld  alpine  RUNNING        RUNNING 10 seconds  worker1
    49      bn67kh76crn6du22ve2enqg5j  helloworld.5  helloworld  alpine  RUNNING        RUNNING 10 seconds  manager1
    50      ```
    51  
    52      You can see that Swarm has created 4 new tasks to scale to a total of 5
    53      running instances of Alpine Linux. The tasks are distributed between the
    54      three nodes of the Swarm. Two are running on `manager1`.
    55  
    56  4. Run `docker ps` to see the containers running on the node where you're
    57  connected. The following example shows the tasks running on `manager1`:
    58  
    59      ```
    60      $ docker ps
    61  
    62      CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
    63      910669d5e188        alpine:latest       "ping docker.com"   10 seconds ago      Up 10 seconds                           helloworld.5.bn67kh76crn6du22ve2enqg5j
    64      a0b6c02868ca        alpine:latest       "ping docker.com"   2 minutes  ago      Up 2 minutes                            helloworld.1.1n6wif51j0w840udalgw6hphg
    65      ```
    66  
    67      If you want to see the containers running on other nodes, you can ssh into
    68      those nodes and run the `docker ps` command.
    69  
    70  ## What's next?
    71  
    72  At this point in the tutorial, you're finished with the `helloworld` service.
    73  The next step shows how to [delete the service](delete-service.md).
    74  
    75  <p style="margin-bottom:300px">&nbsp;</p>