Elastic Container Instance:Create a preemptible elastic container instance

Billing

When you create a preemptible instance, you specify a bid price. If your bid exceeds the real-time market price and inventory is available, the instance starts and enters a protection period (1 hour by default). During this period, you are billed at the market price at the time of creation and the instance is guaranteed to run. After the protection period, billing switches to the real-time market price.

Reclaim mechanism

After the protection period ends, ECI checks the market price and inventory every 5 minutes. If the market price exceeds your bid or inventory runs out, the instance is released.

A SpotToBeReleased event is generated approximately 3 minutes before release. Use this window to drain connections and save state. After reclaim, the instance information is retained, billing stops, and the status changes to Expired.

Creation methods

The vCPU/memory method requires at least 2 vCPUs. Supported combinations:

If you specify a combination that is not listed, ECI automatically uses the next supported higher specification.

Example 1: Fixed instance type with a price cap

Use SpotWithPriceLimit when you want to pin the workload to a specific instance type and set a hard upper bound on hourly cost.

apiVersion: batch/v1
kind: Job
metadata:
  name: test
spec:
  template:
    metadata:
      labels:
        app: perl
        alibabacloud.com/eci: "true"
      annotations:
        k8s.aliyun.com/eci-use-specs: "ecs.c6.large"          # Pin to a specific instance type.
        k8s.aliyun.com/eci-spot-strategy: "SpotWithPriceLimit" # Cap the hourly price.
        k8s.aliyun.com/eci-spot-price-limit: "0.25"           # Maximum price per hour.
    spec:
      containers:
      - name: pi
        image: registry.cn-shanghai.aliyuncs.com/eci_open/perl:5
        command: ["perl", "-Mbignum=bpi", "-wle", "print bpi(2000)"]
      restartPolicy: Never

This creates a preemptible ecs.c6.large instance with a 1-hour protection period. After the protection period:

• If inventory is available and the market price is at or below 0.25 per hour, the instance continues running.

• If the market price exceeds 0.25 per hour or inventory runs out, the instance is released.

If inventory or pricing conditions are not met at creation time, the instance is not created.

Example 2: Auto-selected instance type at market price

Use SpotAsPriceGo when you want ECI to automatically select an instance type based on your vCPU and memory requirements, bidding at the current market price.

Option A: Specify resources in the container spec

apiVersion: batch/v1
kind: Job
metadata:
  name: test
spec:
  template:
    metadata:
      labels:
        app: perl
        alibabacloud.com/eci: "true"
      annotations:
        k8s.aliyun.com/eci-spot-strategy: "SpotAsPriceGo" # Bid at the current market price.
    spec:
      containers:
      - name: pi
        image: registry.cn-shanghai.aliyuncs.com/eci_open/perl:5
        command: ["perl", "-Mbignum=bpi", "-wle", "print bpi(2000)"]
        resources:
          limits:
            cpu: 2000m    # 2 vCPUs
            memory: 4096Mi # 4 GiB memory
      restartPolicy: Never

Option B: Specify resources in an annotation

apiVersion: batch/v1
kind: Job
metadata:
  name: test
spec:
  template:
    metadata:
      labels:
        app: perl
        alibabacloud.com/eci: "true"
      annotations:
        k8s.aliyun.com/eci-use-specs: "2-4Gi"             # 2 vCPUs, 4 GiB memory.
        k8s.aliyun.com/eci-spot-strategy: "SpotAsPriceGo" # Bid at the current market price.
    spec:
      containers:
      - name: pi
        image: registry.cn-shanghai.aliyuncs.com/eci_open/perl:5
        command: ["perl", "-Mbignum=bpi", "-wle", "print bpi(2000)"]
      restartPolicy: Never

Both options create a preemptible instance with 2 vCPUs and 4 GiB of memory. After the 1-hour protection period, the instance is released if the market price rises or inventory runs out.

Example 4: Fallback to pay-as-you-go

Set eci-spot-fallback to "true" to automatically create a pay-as-you-go instance if preemptible inventory is insufficient. This guarantees that a pod is created even when spot capacity is unavailable.

apiVersion: batch/v1
kind: Job
metadata:
  name: test
spec:
  template:
    metadata:
      labels:
        app: perl
        alibabacloud.com/eci: "true"
      annotations:
        k8s.aliyun.com/eci-use-specs: "ecs.c6.large"
        k8s.aliyun.com/eci-spot-strategy: "SpotWithPriceLimit"
        k8s.aliyun.com/eci-spot-price-limit: "0.05"
        k8s.aliyun.com/eci-spot-fallback: "true"              # Fall back to pay-as-you-go if spot is unavailable.
    spec:
      containers:
      - name: pi
        image: registry.cn-shanghai.aliyuncs.com/eci_open/perl:5
        command: ["perl", "-Mbignum=bpi", "-wle", "print bpi(2000)"]
      restartPolicy: Never

Behavior after the pod is created:

• Preemptible instance created: runs normally during the 1-hour protection period; released after the period if the market price exceeds 0.05 per hour or inventory runs out.

• Pay-as-you-go instance created: runs until explicitly deleted; not automatically released.

To check which type was created, run kubectl describe pod and look for a SpotDegraded event. If present, the pod is running on a pay-as-you-go instance.

Interruption warning

ECI generates a SpotToBeReleased event approximately 3 minutes before releasing a preemptible instance. The ContainerInstanceExpired condition in the pod is also set to true. Use this window to drain in-flight requests or checkpoint work.

Run kubectl describe <pod-name> and check the Events section:

Events:
  Type     Reason            Age    From          Message
  ----     ------            ----   ----          -------
  Warning  SpotToBeReleased  3m32s  kubelet, eci  Spot ECI will be released in 3 minutes

Or run kubectl get events to list all events:

LAST SEEN   TYPE      REASON             OBJECT         MESSAGE
3m39s       Warning   SpotToBeReleased   pod/pi-frmr8   Spot ECI will be released in 3 minutes

Status after release

After a preemptible instance is released, its record is retained. Run kubectl get pod to see the updated status:

NAME       READY   STATUS      RESTARTS   AGE
pi-frmr8   1/1     BidFailed   0          3h5m

Run kubectl describe <pod-name> for the full status:

Status:             Failed
Reason:             BidFailed
Message:            The pod is spot instance, and have been released at 2020-04-08T12:36Z