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

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"
}

Answer 1

I was talking to a Microsoft support earlier and this issue is actually a new feature as we can see here https://learn.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.