Elastic Container Instance:Create pods by specifying multiple specifications

How it works

Add the k8s.aliyun.com/eci-use-specs annotation to a pod's metadata. When you submit a pod creation request, the system attempts the specifications in the order you listed them. If the first specification has no available resources, it moves to the next one automatically.

All specifications in the list are tried at the instance level: the retry affects only that single pod's creation policy, not other pods. During the retry process, the pod stays in the Pending state.

What happens if all specifications are exhausted?

If no resources are available for any of the specified specifications, the pod remains Pending. To reduce the risk of this outcome:

• Combine multi-specification mode with multiple zones to further improve the creation success rate.

Supported specification types

You can specify vCPU and memory combinations, Elastic Compute Service (ECS) instance types, or a mix of both in the same annotation.

Configure multi-specification pod creation

Add the k8s.aliyun.com/eci-use-specs annotation to the pod metadata. Specify up to five specifications in priority order, separated by commas.

Limitations:

• For GPU-accelerated, local disk, or Arm-based instances, you can only specify corresponding specifications. Specifications that do not support the target hardware type cannot be specified.

• Preemptible instances cannot use the region-limited vCPU and memory combinations listed in the table above.

The following example creates a Deployment with two replicas. Each pod tries 2-4Gi, then ecs.c5.large, then ecs.c6.large if the previous specification has no available resources.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: test
  labels:
    app: test
spec:
  replicas: 2
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      name: nginx-test
      labels:
        app: nginx
        alibabacloud.com/eci: "true"
      annotations:
        k8s.aliyun.com/eci-use-specs: 2-4Gi,ecs.c5.large,ecs.c6.large  # Specifications in priority order. Replace with actual values.
    spec:
      containers:
      - name: nginx
        image: registry.cn-shanghai.aliyuncs.com/eci_open/nginx:1.14.2
        ports:
        - containerPort: 80

Verify the specification used

After the pod is created, check the k8s.aliyun.com/eci-instance-spec field in the pod's YAML to see which specification was actually used.

Billing

The billing model depends on the specification type used:

• ECS instance type: billed based on the ECS instance type.

• vCPU and memory combination: billed based on the number of vCPUs and the memory size.

For pricing details, see Pricing of ECS instance types.

What's next

• Specify multiple zones to create pods — combine zone diversity with multi-specification mode to further improve the creation success rate.

• Overview of instance families — compare instance family characteristics to choose the right types for your workload.