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(DEPRECATED) Scale agent nodes in a Container Service cluster

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Tip

For the updated version this article that uses Azure Kubernetes Service, see Scale an Azure Kubernetes Service (AKS) cluster.

Warning

The Azure Container Service (ACS) is being deprecated. No new features or functionality are being added to ACS. All of the APIs, portal experience, CLI commands and documentation are marked as deprecated.

For more information, see the Azure Container Service deprecation announcement on Azure.com.

We recommend that you deploy one of the following Azure Marketplace solutions:

If you want to use Kubernetes, see Azure Kubernetes Service.

After deploying an Azure Container Service cluster, you might need to change the number of agent nodes. For example, you might need more agents so you can run more container applications or instances.

You can change the number of agent nodes in a DC/OS, Docker Swarm, or Kubernetes cluster by using the Azure portal or the Azure CLI.

Scale with the Azure portal

  1. In the Azure portal, browse for Container services, and then click the container service that you want to modify.

  2. In the Container service blade, click Agents.

  3. In VM Count, enter the desired number of agents nodes.

    Scale a pool in the portal

  4. To save the configuration, click Save.

Scale with the Azure CLI

Install the Azure CLI and sign in to an Azure account with az login.

See the current agent count

To see the number of agents currently in the cluster, run the az acs show command. This shows the cluster configuration. For example, the following command shows the configuration of the container service named containerservice-myACSName in the resource group myResourceGroup:

az acs show -g myResourceGroup -n containerservice-myACSName

The command returns the number of agents in the Count value under AgentPoolProfiles.

Use the az acs scale command

To change the number of agent nodes, run the az acs scale command and supply the resource group, container service name, and the desired new agent count. By using a smaller or higher number, you can scale down or up, respectively.

For example, to change the number of agents in the previous cluster to 10, type the following command:

az acs scale -g myResourceGroup -n containerservice-myACSName --new-agent-count 10

The Azure CLI returns a JSON string representing the new configuration of the container service, including the new agent count.

For more command options, run az acs scale --help.

Scaling considerations

  • The number of agent nodes must be between 1 and 100, inclusive.

  • Your cores quota can limit the number of agent nodes in a cluster.

  • Agent node scaling operations are applied to an Azure virtual machine scale set that contains the agent pool. In a DC/OS cluster, only agent nodes in the private pool are scaled by the operations shown in this article.

  • Depending on the orchestrator you deploy in your cluster, you can separately scale the number of instances of a container running on the cluster. For example, in a DC/OS cluster, use the Marathon UI to change the number of instances of a container application.

Next steps