Elastic High Performance Computing:Scale out a hybrid cloud cluster

Prerequisites

• A vSwitch is available in the region where the scale-out nodes reside. For more information, see Work with vSwitches.

• Sufficient Elastic Compute Service (ECS) instance quotas exist in the region where the scale-out nodes reside. For more information, see View and increase instance quotas.

Background information

E-HPC provides the following scale-out modes for a hybrid cloud cluster. You can select one based on your needs:

• Ordinary scale-out: You can select scale-out nodes from only one zone. The zone can be different from the zone where the existing compute nodes reside. For more information, see Ordinary scale-out.

• Multi-zone scale-out: The policy of scale-out nodes varies by their billing methods. Scale-out nodes may have the following policies:

  • Priority-oriented: The policy applies when the billing method of scale-out nodes is pay-as-you-go. The order in which zones and vSwitches are specified determines their priorities. E-HPC preferentially attempts to select compute nodes from the zone where the vSwitch with the highest priority resides. If the attempt fails, E-HPC attempts to select compute nodes from the zone where the vSwitch with the next highest priority resides.

  • Cost-oriented: The policy applies when scale-out nodes are preemptible instances. Scale-out is performed at lower cost and release rates.

  For more information, see Multi-zone scale-out.

Ordinary scale-out

1. Log on to the E-HPC console.

2. In the top navigation bar, select a region.

3. In the left-side navigation pane, click Cluster.

4. On the Cluster page, find the cluster that you want to scale out and click Resize.

5. In the Resize panel, click the Scale Out tab and set the scale-out parameters.

   Parameter	Description
   Zone	The zone where the scale-out nodes reside. The scale-out nodes and cluster can reside in different zones.
   vSwitch ID	The ID of an available vSwitch in the specified zone. Unavailable vSwitches are not displayed in the drop-down list. The scale-out nodes are deployed in a vSwitch.
   Pricing Model	Subscription: You can purchase or renew compute nodes by week, month, or year. Pay-As-You-Go: You are charged for compute nodes on an hourly basis. Preemptible Instance: Preemptible instances are a type of on-demand instances that are offered at a discounted price compared with pay-as-you-go instances. For more information, see Billing method overview.
   Quantity And Type of Instances to be Added	The number of compute nodes to be added to the cluster. You can add a maximum of 200 compute nodes. To add more nodes, submit a ticket.
   Image Type	The image type of the scale-out nodes. Valid values: Public Image, Custom Image, and Share Image. Notice If you set Image Type to Custom Image, the custom image that you select must be created from compute nodes, not from logon nodes or management nodes. Otherwise, exceptions may occur when you scale out the cluster.
   Image	Select the image of the scale-out nodes. The image must meet the following conditions: The operating system of the scale-out node image is the same as that of the nodes in the cluster. For example, if the operating system of the nodes in the cluster is CentOS, only a CentOS image can be selected. The major version of the scale-out node image is the same as that of the cluster node image. For example, if the version of the cluster node image is CentOS 7.x, the version of the scale-out node image must be CentOS 7.x.
   Assign Public IP Address	If the scale-out nodes need to access the Internet, you can turn on the switch. Otherwise, the scale-out nodes can access only the resources in the VPC.
   Queue	The queue of the scale-out nodes. If you do not specify this parameter, the default queue is selected.
   Hostname Prefix and Hostname Suffix	Specify a prefix and suffix to facilitate compute node management.
   System Disk	The system disk size of the scale-out nodes. By default, an ultra disk is used. If no ultra disk is available in the current zone, an SSD disk is used.

6. In the Current Configurations section, check the settings that you configured. Read and select Alibaba Cloud International Website Product Terms of Service, and click Buy Now.

Multi-zone scale-out

1. Log on to the E-HPC console.

2. In the top navigation bar, select a region.

3. In the left-side navigation pane, click Cluster.

4. On the Cluster page, find the cluster that you want to scale out and click Resize.

5. In the Resize panel, click the Multi-Zone Scale Out tab and set the scale-out parameters.

   Parameter	Description
   Quantity And Type of Instances to be Added	The number of compute nodes to be added to the cluster. You can add a maximum of 200 compute nodes. To add more nodes, submit a ticket.
   Zone and vSwitch ID	The zone where the scale-out nodes reside. The E-HPC console displays all zones that have available instance types that you specified. The policy of scale-out nodes varies by their billing methods. You can select one policy based on your needs. Scale-out nodes may have the following policies: Priority-oriented: The policy applies when the billing method of scale-out nodes is pay-as-you-go. The order in which zones and vSwitches are specified determines their priorities. E-HPC preferentially attempts to select compute nodes from the zone where the vSwitch with the highest priority resides. If the attempt fails, E-HPC attempts to select compute nodes from the zone where the vSwitch with the next highest priority resides. Cost-oriented: The policy applies when scale-out nodes are preemptible instances. Scale-out is performed at lower cost and release rates.
   Type	A hybrid cloud cluster supports the following scale-out methods. You can select one based on the number and storage performance of scale-out nodes. Scale Out: If you need to add no more than 50 compute nodes, we recommend that you select this method. Batch Job for Scale Out: If you need to add more than 50 compute nodes, we recommend that you select this method to prevent your business from being affected.
   Batch Job for Scale Out	If you set Type to Batch Job for Scale Out, you must specify Batch Job Count. Valid values: 1 to 10. Batch Job Count: the number of batches that compute nodes are added. If 100 compute nodes are added in two batches, 50 nodes are added during each batch.
   Pricing Model	Pay-As-You-Go: You are charged for compute nodes on an hourly basis. Preemptible Instance: Preemptible instances are a type of on-demand instances that are offered at a discounted price compared with pay-as-you-go instances. For more information, see Billing method overview.
   Image Type	The image type of the scale-out nodes. Valid values: Public Image, Custom Image, and Share Image. Notice If you set Image Type to Custom Image, the custom image that you select must be created from compute nodes, not from logon nodes or management nodes. Otherwise, exceptions may occur when you scale out the cluster.
   Image	Select the image of the scale-out nodes. The image must meet the following conditions: The operating system of the scale-out node image is the same as that of the nodes in the cluster. For example, if the operating system of the nodes in the cluster is CentOS, only a CentOS image can be selected. The major version of the scale-out node image is the same as that of the cluster node image. For example, if the version of the cluster node image is CentOS 7.x, the version of the scale-out node image must be CentOS 7.x.
   Assign Public IP Address	If the scale-out nodes need to access the Internet, you can turn on the switch. Otherwise, the scale-out nodes can access only the resources in the VPC.
   Queue	The queue of the scale-out nodes. If you do not specify this parameter, the default queue is selected.
   Hostname Prefix and Hostname Suffix	Specify a prefix and suffix to facilitate compute node management.
   System Disk	The system disk size of the scale-out nodes. By default, an ultra disk is used. If no ultra disk is available in the current zone, an SSD disk is used.

6. In the Current Configurations section, check the settings that you configured. Read and select Alibaba Cloud International Website Product Terms of Service, and click Buy Now.

Result

After you scale out the cluster, the added compute nodes automatically install and initialize the cluster application. The original compute nodes are not affected.

To query the status of scale-out nodes, choose Resource Management > Nodes in the left-side navigation pane. Select the cluster that you scaled out from the Cluster drop-down list. Select Compute Node from the Node Type drop-down list. If the nodes are in the Running state, the cluster is scaled out.