Best practices for node pool deployment sets

Feature usage notes in clusters

• Deployment sets support only ACK managed clusters and ACK dedicated clusters.

• Specify a deployment set only when creating a node pool. Deployment sets cannot be enabled for existing node pools. Each node pool supports one deployment set.

• You cannot manually add or remove nodes from a deployment set. Scale the node pool to adjust node count. See Create and manage node pools.

• Node pools with deployment sets do not support spot instances.

Deployment set quotas and instance type limits

• Deployment set quota limits:

  • Node pool deployment sets use the high availability policy by default. You can create up to 20 ECS instances per zone within a deployment set. The total ECS instance count per Alibaba Cloud region is 20 × number of zones . Ensure sufficient ECS instance quotas and inventory for your required instance types. See Deployment sets .

    The maximum instance count per deployment set cannot be increased. To raise the maximum number of deployment sets for your account, apply through the Quota Center. See Limits on deployment sets.

  • If creating an ECS instance in a deployment set or restarting a pay-as-you-go instance (in economical mode) fails, the cause may be insufficient inventory. Wait and retry.

• Instance family restrictions: Most instance families of generation 6 or later support deployment sets that use the high availability, high availability group, and low latency strategies.

  Different deployment strategies support specific instance families.

  For a definitive list of supported instance families, see the response returned by the DescribeDeploymentSetSupportedInstanceTypeFamily API operation.

  Deployment strategy	Supported instance families
  high availability strategy and high availability group strategy	g9a, g9ae, g9i, g8a, g8i, g8ine, g8ise, g8y, g7, g7a, g7h, g7ne, g7nex, g7se, g7t, g6, g6a, g6e, g6h, g5, g5ne c9a, c9ae, c9i, c8a, c8i, c8ine, c8y, c7, c7a, c7nex, c7se, c7t, c6, c6a, c6e, c5 r9a, r9ae, r9i, r8a, r8i, r8y, r7, r7a, r7se, r7t, r6, r6a, r6e, r5 hfc9i, hfg9i, hfr9i, hfc8i, hfg8i, hfr8i, hfc7, hfg7, hfr7, hfc6, hfg6, hfr6, hfc5, hfg5 ebmc9i, ebmg9a, ebmg9i, ebmr9i, ebmc8a, ebmc8i, ebmc8y, ebmg8a, ebmg8i, ebmg8y, ebmr8a, ebmr8y, ebmc7, ebmc7a, ebmg7, ebmg7a, ebmg7se, ebmhfc7, ebmhfg7, ebmhfr7, ebmr7, ebmr7a, ebmg5 i5, i5g, i5ge, ic5, i4, i4g, i4r, i3, i3g, i2, i2g, i2gne, i2ne gn6i d3c, d3s, d2c, d2s, d1ne re6, re6p, s6, t6, e4, mn4, n4, re4, xn4, sn2ne, u2a, u2i, se1, se1ne, sn1ne, u1, e
  low latency strategy	g9a, g9ae, g9i, g8a, g8ae, g8i, g8ise, g8y, g7, g5ne c9a, c9ae, c9i, c8a, c8ae, c8i, c8ine, c8y, c7, c7nex r9a, r9ae, r9i, r8a, r8ae, r8i, r8y, r7 hfc9i, hfg9i, hfr9i, hfc8i, hfg8i, hfr8i ebmc9i, ebmg9a, ebmg9i, ebmr9i, ebmc8a, ebmc8i, ebmc8y, ebmg8a, ebmg8i, ebmg8y, ebmgn8v, ebmr8a, ebmr8y, ebmc7, ebmc7a, ebmg7, ebmg7a, ebmg7se, ebmgn7ex, ebmhfc7, ebmhfg7, ebmhfr7, ebmr7, ebmr7a i5, i5g, i5ge, i4 gn8v hpc8ae, hpc8i, hpc7ip, hpc6id, u2a, u2i

Schedule pods from the same workload in a single node pool so that only one pod runs per node using pod anti-affinity

Schedule three pod replicas from a Deployment onto three different nodes.

1. Create a node pool with three nodes and assign a deployment set.

   After creation, on the Node Pools page, click the node pool. On the Nodes tab, verify that three nodes were created.

   Log on to the ECS console. In the left navigation pane, choose Deployment & Elasticity > Deployment Set. On the Deployment Set page, verify that all three nodes belong to the deployment set.

2. Configure your application with the following YAML.

   Set pod anti-affinity to schedule three application pods onto different nodes.

   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: nginx
     labels:
       app: nginx
   spec:
     replicas: 3
     selector:
       matchLabels:
         app: nginx
     template:
       metadata:
         name: nginx
         labels:
           app: nginx
       spec:
         affinity:
           podAntiAffinity:
             requiredDuringSchedulingIgnoredDuringExecution:  # Set the scheduling policy.
             - labelSelector:
                 matchExpressions:
                 - key: app
                   operator: In
                   values:
                   - nginx
               topologyKey: kubernetes.io/hostname
         nodeSelector:
             alibabacloud.com/nodepool-id: <nodepool-id>  # Specify the node pool ID.
         containers:
         - name: nginx
           image: anolis-registry.cn-zhangjiakou.cr.aliyuncs.com/openanolis/nginx:1.14.1-8.6
           resources:
             limits:
               cpu: 1
             requests:
               cpu: 1

   Execution Result

   On the Deployments page, click the target Deployment. On the Pods tab, the three pods are scheduled onto different nodes.

Distribute pods from the same workload evenly across zones and nodes within a single node pool

1. Create a node pool with four nodes, assign a deployment set, and select vSwitches in multiple zones.

   After creation, on the Node Pools page, click the node pool. On the Nodes tab, verify that four nodes exist across four zones. Per ESS’s even distribution policy, the ECS instances are spread across four zones and belong to the deployment set.

   Log on to the ECS console. In the left navigation pane, choose Deployment & Elasticity > Deployment Set. On the Deployment Set page, verify that all four nodes belong to the deployment set.

2. Configure your application with the following YAML.

   Use pod topology spread constraints to distribute pods from the same application evenly across zones and nodes.

   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: nginx
     labels:
       app: nginx
   spec:
     replicas: 4
     selector:
       matchLabels:
         app: nginx
     template:
       metadata:
         name: nginx
         labels:
           app: nginx
       spec:
         topologySpreadConstraints:
           - maxSkew: 1
             topologyKey: kubernetes.io/hostname
             whenUnsatisfiable: DoNotSchedule
             labelSelector:
               matchLabels:
                 app: nginx
           - maxSkew: 1
             topologyKey: topology.kubernetes.io/zone
             whenUnsatisfiable: DoNotSchedule
             labelSelector:
               matchLabels:
                 app: nginx
         nodeSelector:
           alibabacloud.com/nodepool-id: <nodepool-id>  # Specify the node pool ID.
         containers:
         - name: nginx
           image: anolis-registry.cn-zhangjiakou.cr.aliyuncs.com/openanolis/nginx:1.14.1-8.6
           resources:
             limits:
               cpu: 1
             requests:
               cpu: 1

   Execution Result

   On the Deployments page, click the target Deployment. On the Pods tab, the pods are evenly distributed across zones and nodes.