Pin a container to a set of hosts using allocation tagging
In DuploCloud, allocation tags give you control over where containers and Services are deployed within a Kubernetes cluster. By default, DuploCloud spreads container replicas across available Hosts to balance resource usage. Allocation tags allow you to label Hosts and Services with specific characteristics, capabilities, or preferences, and to "pin" Services to certain Hosts to meet your operational and resource needs. Allocation tags are useful for deployment requirements like using Hosts with specialized resources, meeting compliance standards, or isolating workloads.
For a Service to run on a specific Host, the Host and the Service must have matching allocation tags. Services without allocation tags are deployed on any available Host in the Kubernetes cluster.
Assign a tag describing the Host's characteristics or capabilities, such as resource capacity, geographic location, or compliance needs.
In the DuploCloud Portal, navigate to Cloud Services -> Hosts. The Hosts page displays.
Select the Host from the NAME column. If the Host is part of an Auto-Scaling Group (ASG), select the ASG tab and select the correct ASG.
Click the Allocation Tag Edit Icon ( ). The Set Allocation Tag pane displays.
In the Allocation Tag field, enter a tag name. Use only alphanumeric characters. Hyphens ( - ) are supported as special characters if needed. For example, highmemory-highcpu is a valid tag name.
Click Set. The allocation tag you set displays in the heading banner for the Host or ASG.
In the DuploCloud Portal, navigate to the Add Service or Edit Service page, and enter a tag name in the Allocation Tag field. When the Service runs, DuploCloud will attempt to select a Host with a matching allocation tag. To pin the Service to run on a specific Host, apply matching allocation tags to the Host and Service.
On the Host or ASG page, select the Metadata tab, and edit or delete the existing allocation tag.