Using Automatic Instance Groups
When you create an instance group in Altus Director, you can configure it to be an automatic instance group. An automatic instance group uses instances that are created and managed as a group in the cloud provider. For clusters in AWS, when you create an automatic instance group, Altus Director creates an AWS Auto Scaling group. For clusters in Azure, Altus Director creates an Azure virtual machine scale set (VMSS).
Using automatic instance groups can provide some advantages. Because instances are created as a group, the Altus Director bootstrap time is reduced. Instance groups in the cloud provider also tend to be more reliable and have additional features. For more information about AWS Auto Scaling groups, see Auto Scaling Groups in the AWS documentation. For more information about Azure VMSS, see Virtual Machines Scale Sets in the Microsoft Azure documentation.
An automatic instance group is an advanced option. When you use a configuration file to create a cluster, you must set the automatic parameter in the reference configuration file to true. For more information about the automatic parameter, see the reference Altus Director configuration files. For clusters in AWS, search for Use Auto Scaling Group (ASG) in the AWS reference configuration file. For clusters in Azure, search for use an Azure Virtual Machine Scale Set (VMSS) in the Azure reference configuration file.
When you use the Altus Director UI to create a cluster, you must use the advanced setup procedure. For clusters in AWS, select Use Auto Scaling Groups in the Advanced Options section. For more information about advanced setup for AWS clusters, see Advanced Setup: Installing Cloudera Manager and CDH on AWS.
For clusters in Azure, select Use Virtual Machine Scale Set (VMSS) in the Advanced Options section. For more information about the advanced setup for Azure clusters, see Advanced Setup: Installing Cloudera Manager and CDH on Azure.
To create and use automatic instance groups, you must have the appropriate permissions in your cloud provider. For information about the required permissions in AWS, see Creating AWS Identity and Access Management (IAM) Policies. For information about the required permissions in Azure, see Obtaining Credentials for Altus Director.