Use AKS Uptime SLA#

Reliability · Azure Kubernetes Service · 2022_09

AKS clusters should have Uptime SLA enabled to ensure availability of control plane components for production workloads.

Description#

Uptime SLA is a tier to enable a financially backed, higher SLA for an AKS cluster. Clusters with Uptime SLA, come with greater amount of control plane resources and automatically scaling. Uptime SLA guarantees 99.95% availability of the Kubernetes API server endpoint for clusters that use Availability Zones. Uptime SLA guarantees 99.9% of availability for clusters that don't use Availability Zones. AKS uses master node replicas across update and fault domains to ensure SLA requirements are met.

AKS recommends use of Uptime SLA in production workloads to ensure availability of control plane components. Clusters on the Free SKU tier support fewer replicas and limited resources for the control plane.

Recommendation#

Consider enabling Uptime SLA for production deployments.

Examples#

Configure with Azure template#

To deploy an AKS cluster that pass this rule:

Set sku.tier to Paid.

For example:

Azure Template snippet

{
  "type": "Microsoft.ContainerService/managedClusters",
  "apiVersion": "2022-06-02-preview",
  "name": "[parameters('clusterName')]",
  "location": "[parameters('location')]",
  "sku": {
    "name": "Basic",
    "tier": "Paid"
  },
  "identity": {
    "type": "SystemAssigned"
  },
  "properties": {
    "dnsPrefix": "[parameters('dnsPrefix')]",
    "agentPoolProfiles": [
      {
        "name": "agentpool",
        "osDiskSizeGB": "[parameters('osDiskSizeGB')]",
        "count": "[parameters('agentCount')]",
        "vmSize": "[parameters('agentVMSize')]",
        "osType": "Linux",
        "mode": "System"
      }
    ],
    "linuxProfile": {
      "adminUsername": "[parameters('linuxAdminUsername')]",
      "ssh": {
        "publicKeys": [
          {
            "keyData": "[parameters('sshRSAPublicKey')]"
          }
        ]
      }
    }
  }
}

Configure with Bicep#

To deploy an AKS cluster that pass this rule:

Set sku.tier to Paid.

For example:

Azure Bicep snippet

resource aks 'Microsoft.ContainerService/managedClusters@2022-06-02-preview' = {
  name: clusterName
  location: location
  sku: {
    name: 'Basic'
    tier: 'Paid'
  }
  identity: {
    type: 'SystemAssigned'
  }
  properties: {
    dnsPrefix: dnsPrefix
    agentPoolProfiles: [
      {
        name: 'agentpool'
        osDiskSizeGB: osDiskSizeGB
        count: agentCount
        vmSize: agentVMSize
        osType: 'Linux'
        mode: 'System'
      }
    ]
    linuxProfile: {
      adminUsername: linuxAdminUsername
      ssh: {
        publicKeys: [
          {
            keyData: sshRSAPublicKey
          }
        ]
      }
    }
  }
}

Links#

Last update: 2022-12-03