Chapter 10. Scaling overcloud nodes

Procedure

1. Create a new JSON file called newnodes.json that contains details of the new node that you want to register:

   {
     "nodes":[
       {
           "mac":[
               "dd:dd:dd:dd:dd:dd"
           ],
           "cpu":"4",
           "memory":"6144",
           "disk":"40",
           "arch":"x86_64",
           "pm_type":"ipmi",
           "pm_user":"admin",
           "pm_password":"p@55w0rd!",
           "pm_addr":"192.02.24.207"
       },
       {
           "mac":[
               "ee:ee:ee:ee:ee:ee"
           ],
           "cpu":"4",
           "memory":"6144",
           "disk":"40",
           "arch":"x86_64",
           "pm_type":"ipmi",
           "pm_user":"admin",
           "pm_password":"p@55w0rd!",
           "pm_addr":"192.02.24.208"
       }
     ]
   }

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2. Log in to the undercloud host as the stack user.

3. Source the stackrc undercloud credentials file:

   $ source ~/stackrc

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4. Register the new nodes:

   $ openstack overcloud node import newnodes.json

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5. Launch the introspection process for each new node:

   $ openstack overcloud node introspect \
    --provide <node_1> [<node_2>] [<node_n>]

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   • Use the --provide option to reset all the specified nodes to an available state after introspection.
   • Replace <node_1>, <node_2>, and all nodes up to <node_n> with the UUID of each node that you want to introspect.

6. Configure the image properties for each new node:

   $ openstack overcloud node configure <node>

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Procedure

1. Log in to the undercloud host as the stack user.

2. Source the stackrc undercloud credentials file:

   $ source ~/stackrc

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3. Open the overcloud-baremetal-deploy.yaml node definition file that you use to provision your bare-metal nodes.

4. Increment the count parameter for the roles that you want to scale up. For example, the following configuration increases the Object Storage node count to 4:

   - name: Controller
     count: 3
   - name: Compute
     count: 10
   - name: ObjectStorage
     count: 4

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5. Optional: Configure predictive node placement for the new nodes. For example, use the following configuration to provision a new Object Storage node on node03:

   - name: ObjectStorage
     count: 4
     instances:
     - hostname: overcloud-objectstorage-0
       name: node00
     - hostname: overcloud-objectstorage-1
       name: node01
     - hostname: overcloud-objectstorage-2
       name: node02
     - hostname: overcloud-objectstorage-3
       name: node03

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6. Optional: Define any other attributes that you want to assign to your new nodes. For more information about the properties you can use to configure node attributes in your node definition file, see Bare-metal node provisioning attributes.
7. If you use the Object Storage service (swift) and the whole disk overcloud image, overcloud-hardened-uefi-full, configure the size of the /srv partition based on the size of your disk and your storage requirements for /var and /srv. For more information, see Configuring whole disk partitions for the Object Storage service.

8. Provision the overcloud nodes:

   $ openstack overcloud node provision \
     --stack <stack> \
     --network-config \
     --output <deployment_file> \
     /home/stack/templates/overcloud-baremetal-deploy.yaml

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   • Replace <stack> with the name of the stack for which the bare-metal nodes are provisioned. If not specified, the default is overcloud.
   • Include the --network-config argument to provide the network definitions to the cli-overcloud-node-network-config.yaml Ansible playbook.

   • Replace <deployment_file> with the name of the heat environment file to generate for inclusion in the deployment command, for example /home/stack/templates/overcloud-baremetal-deployed.yaml.

     Note

     If you upgraded from Red Hat OpenStack Platform 16.2 to 17.1, you must include the YAML file that you created or updated during the upgrade process in the openstack overcloud node provision command. For example, use the /home/stack/tripleo-[stack]-baremetal-deployment.yaml file instead of the /home/stack/templates/overcloud-baremetal-deployed.yaml file. For more information, see Performing the overcloud adoption and preparation in Framework for upgrades (16.2 to 17.1).

9. Monitor the provisioning progress in a separate terminal. When provisioning is successful, the node state changes from available to active:

   $ watch openstack baremetal node list

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10. Add the generated overcloud-baremetal-deployed.yaml file to the stack with your other environment files and deploy the overcloud:

    $ openstack overcloud deploy --templates \
      -e [your environment files] \
      -e /home/stack/templates/overcloud-baremetal-deployed.yaml \
      --disable-validations \
      ...

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Procedure

1. Log in to the undercloud host as the stack user.

2. Source the stackrc undercloud credentials file:

   $ source ~/stackrc

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3. Decrement the count parameter in the overcloud-baremetal-deploy.yaml file, for the roles that you want to scale down.
4. Define the hostname and name of each node that you want to remove from the stack, if they are not already defined in the instances attribute for the role.

5. Add the attribute provisioned: false to the node that you want to remove. For example, to remove the node overcloud-objectstorage-1 from the stack, include the following snippet in your overcloud-baremetal-deploy.yaml file:

   - name: ObjectStorage
     count: 3
     instances:
     - hostname: overcloud-objectstorage-0
       name: node00
     - hostname: overcloud-objectstorage-1
       name: node01
       # Removed from cluster due to disk failure
       provisioned: false
     - hostname: overcloud-objectstorage-2
       name: node02
     - hostname: overcloud-objectstorage-3
       name: node03

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   After you redeploy the overcloud, the nodes that you define with the provisioned: false attribute are no longer present in the stack. However, these nodes are still running in a provisioned state.

   Note

   If you want to remove a node from the stack temporarily, after you deploy the overcloud with the attribute provisioned: false, you can then redeploy the overcloud with the attribute provisioned: true to return the node to the stack.

6. Delete the node from the overcloud:

   $ openstack overcloud node delete \
     --stack <stack> \
     --baremetal-deployment \
      /home/stack/templates/overcloud-baremetal-deploy.yaml

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   • Replace <stack> with the name of the stack for which the bare-metal nodes are provisioned. If not specified, the default is overcloud.

     Note

     Do not include the nodes that you want to remove from the stack as command arguments in the openstack overcloud node delete command.

7. Delete the ironic node:

   $ openstack baremetal node delete <ironic_node_uuid>

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   Replace <ironic_node_uuid> with the UUID of the node.

8. Delete the network agents for the node that you deleted:

   (overcloud)$ for AGENT in $(openstack network agent list \
     --host <ironic_node_uuid> -c ID -f value) ; \
     do openstack network agent delete $AGENT ; done

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9. Provision the overcloud nodes to generate an updated heat environment file for inclusion in the deployment command:

   $ openstack overcloud node provision \
     --stack <stack> \
     --output <deployment_file> \
     /home/stack/templates/overcloud-baremetal-deploy.yaml

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   • Replace <deployment_file> with the name of the heat environment file to generate for inclusion in the deployment command, for example /home/stack/templates/overcloud-baremetal-deployed.yaml.

10. Add the overcloud-baremetal-deployed.yaml file generated by the provisioning command to the stack with your other environment files, and deploy the overcloud:

    $ openstack overcloud deploy \
      ...
      -e /usr/share/openstack-tripleo-heat-templates/environments \
      -e /home/stack/templates/overcloud-baremetal-deployed.yaml \
      --disable-validations \
      ...

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Procedure

1. Prepare the new pre-provisioned nodes. For more information, see Pre-provisioned node requirements.
2. Scale up the nodes. For more information, see Scaling overcloud nodes.

Procedure

1. Retrieve the names of the nodes that you want to remove:

   $ openstack stack resource list overcloud -n5 --filter type=OS::TripleO::ComputeDeployedServerServer

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2. Delete the nodes:

   $ openstack overcloud node delete --stack <overcloud> <node> [... <node>]

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   • Replace <overcloud> with the name or UUID of the overcloud stack.
   • Replace <node> with the host names of the nodes that you want to remove, retrieved from the stack_name column returned in step 1.

3. Ensure that the node is deleted:

   $ openstack stack list

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   The status of the overcloud stack shows UPDATE_COMPLETE when the delete operation is complete.

4. Power off the removed nodes. In a standard deployment, the bare-metal services on director power off the removed nodes. With pre-provisioned nodes, you must either manually shut down the removed nodes or use the power management control for each physical system. If you do not power off the nodes after removing them from the stack, they might remain operational and reconnect as part of the overcloud environment.

5. Re-provision the removed nodes to a base operating system configuration so that they do not unintentionally join the overcloud in the future.

   Note

   Do not attempt to reuse nodes previously removed from the overcloud without first reprovisioning them with a fresh base operating system. The scale down process only removes the node from the overcloud stack and does not uninstall any packages.