IBM Cloud Docs
Updating the maximum number of worker nodes

Updating the maximum number of worker nodes

Making updates to the Symphony configuration by using the GUI

You can make updates to your Symphony configuration by using the GUI console or through the CLI.

Configuration updates by using Symphony GUI console

For more information on how to use the Symphony GUI console, see Symphony GUI console.

After you login to the console, complete the following steps to update the maximum number of worker nodes:

  1. From the cluster management console, click Menu icon Menu icon Resources > Cloud > Configuration.

  2. In the Cloud Configuration page, update the HostFactory service configuration, your cloud provider's host template, or both. If your updates do not include optional parameters, the parameters default values are used.

  3. To update the cloud provider's host template definition, select ibmcloudgen2inst from the provider list and edit your existing template definition in the templates text box.

  4. Modify the values for following:

    a. maxNumber changes the maximum number of worker nodes.

    b. imageId changes the ID of the custom image.

    c. vmType changes the instance type. If you modify the instance type, you need to modify the corresponding values for ncpus and nram in the attributes section. For example, if you choose bx2-2x8, this instance type has 2 VCPUs and 8GB of RAM. Since VCPUs includes hyper-threads, use VCPUs divided by 2, to get ncpus. Set ncpus to 1 and nram to 8192.

    d. postProvisionFile changes the location of the post provision script.

    e. hostPrefix changes the prefix of provisioned hosts

The changes take effect automatically. There is no need to restart the HostFactory service.

Configuration updates using Symphony CLI

  1. Find and edit the following file on your management node. Replace the CLUSTER value with the name of your cluster. The default value is HPCCluster: /data/<CLUSTER>/sym731/hostfactory/conf/providers/ibmcloudgen2inst/ibmcloudgen2instprov_templates.json

  2. Modify the values for following:

    a. maxNumber property updates the maximum number of worker nodes.

    b. imageId changes the ID of the custom image.

    c.vmType changes the instance type. If you modify the instance type, you will also need to modify the corresponding values for ncpus and nram in the attributes section. For example, if you choose bx2-2x8, this instance type has 2 VCPUs and 8GB of RAM. Since VCPUs includes hyper-threads, use VCPUs divided by 2 to get ncpus. Set ncpus to 1 and nram to 8192.

    d. postProvisionFile changes the location  of the post provision script.

    e. hostPrefix changes the prefix of provisioned hosts.

  3. Save the file.

  4. Restart the HostFactory service by using the following commands:

    egosh service stop HostFactory

    egosh service start HostFactory

For more information, see Dynamically updating host factory configuration.