Azure service fabric node type instance count doubled on creating cluster using ARM

Question

I'm experimenting on creating a new service fabric cluster using ARM template and modify the template to add certificates, etc. The cluster and all resources are successfully created, but I noticed that initially the number of node instances are 2x, plus 1 than what I set to. For example, if I set "vmInstanceCount" to 3, I see 7 instances are currently creating.

But if I just wait and let them finish, then 4 instances were deleted and it will keep the three instances. One problem here is that it randomly select what to keep, thus, the names to keep can be node_1, node_4, node_6 which is messy.

Here's my snippet of nodeType:

"nodeTypes": [
  {
    "name": "[variables('vmNodeType0Name')]",
    "applicationPorts": {
      "endPort": 30000,
      "startPort": 20000
    },
    "clientConnectionEndpointPort": "[variables('fabricTcpGatewayPort')]",
    "ephemeralPorts": {
      "endPort": 65534,
      "startPort": 49152
    },
    "httpGatewayEndpointPort": "[variables('fabricHttpGatewayPort')]",
    "isPrimary": true,
    "vmInstanceCount": "[variables('vmInstanceCount')]",
    "reverseProxyEndpointPort": "[variables('reverseProxyEndpointPort')]",
    "durabilityLevel": "Bronze"
  }
]

...

  "sku": {
    "name": "[variables('vmssSkuName')]",
    "capacity": "[variables('vmssSkuCapacity')]",
    "tier": "Standard"
  }

marvs marvs · Accepted Answer · 2017-07-03T06:01:47

I was talking to a Microsoft support earlier and this issue is actually a new feature as we can see here https://docs.microsoft.com/en-us/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-design-overview#overprovisioning I will close this issue as I found the answer. However, I still have some concern on the naming part but I will throw that question to MS.

Azure service fabric node type instance count doubled on creating cluster using ARM

1 Answers