1015 Build a Cluster using Machine Pools¶

10 Minutes introductory

Use the Pool Broker to allocate multiple clusters of machines from shared set of existing machines. Very helpful for limited resources or machines with long setup cycles.

Business ROI: Treat bare metal machines as a dynamic shared resource.

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Prerequisites¶

Additional Labs:

1010

Concepts¶

clusters
resorce brokers

Summary¶

Define a Pool¶

Navigate to the Pools table and click the Create button
Provide the Id as lab1015 Digital Rebar does NOT require pools to be pre-defined; however, you cannot define the insert/remove/allocate/release actions of a pool unless you have created a pool resource.

Optionally, set Meta Icon to user Setting the icon makes it easier to identify machines in our target pool.

The Machines view does _not_ use the color property for pools because
pools are shown black if `Free` and green if `InUse`.

Save the Pool

Create the source `lab1015` Cluster to fill the pool¶

This cluster will provide the machines for our test pool. In a bare metal environment, these would be provided through a discovery or registration process.

Navigate to the Clusters table and click the Add button Name your Cluster lab1015

Choose the `context-broker` for the `broker/name` Parameter.

Update the `cluster/count` to `10`.

Save the Cluster and allow it to progress to Work Order mode.

Observe the Cluster's Activity as it builds the Cluster to the "cluster-provision" task

Put the `lab1015-#` machines into the `lab1015` Pool¶

Select all lab1015-# from Machines
Insert all lab1015-# machines into the lab1015 Pool Using the Actions...Pools...Insert menu option to show the actions panel Select Pool lab1015 Click "Commit 1 action" to apply the change. You should see the Pool column change from boxes (default) to a user (lab1015) At this point, you should be able to see the instances created the target cloud.

Create a `lab1015-broker` Resource Broker using Pool `lab1015`¶

Navigate to Resource Brokers click the Add button
Select the resource-pool Resource Profile and name your broker lab1015-broker
Provide the Required Params Set broker-pool/pool to lab1015
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Leave `broker-pool/allocate` set to true.
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Save the Broker
Wait for the Broker to change into Work Order mode

Allocate the consumption Clusters¶

Clusters that use the Pool Broker will allocate existing machines from the pools rather than creating new machines. When the machines are removed from the cluster, they are released back into the pool and the release action is applied.

Navigate to the Clusters table and click the Add button Name your Cluster circle

Choose the `lab1015-broker` for the `broker/name` Parameter.

Update the `cluster/count` to `5`.

Set the Icon to `circle`

Save the Cluster

Observe the Cluster's machines on the Machines view. Notice that the Cluster Profile is added to the profiles list
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Notice that the PoolStatus is now InUse instead of Free
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Navigate to the Clusters table and click the Add button Name your Cluster square

Choose the `lab1015-broker` for the `broker/name` Parameter.

Update the `cluster/count` to `5`.

Set the Icon to `square`

Save the Cluster

Observe the Cluster's machines on the Machines view. Notice that the Cluster Profile is added to the profiles list
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Notice that the PoolStatus is now InUse instead of Free
```

Explore the Pool allocation¶

The following are suggested activities to better understand how the pool broker allocates and releases resources from the pools.

Increase the size of square to 6 and apply the universal-application-base-cluster blueprint Notice that request does not complete because the pool is out of machines
Descreate the size of circle to 2 and apply the universal-application-base-cluster blueprint Notice that the released machines automatically run the load-generator workflow because it was assigned as the release action in the pool
In square, reapply the universal-application-base-cluster blueprint Notice that request completes because machines have been freed from circle

Cleanup your clusters¶

From the Clusters table, select square, and circle to release the machines For safety reasons, you cannot delete machines that are InUse
Use the Actions list to return your Cluster to Workflow mode
Use the Actions list to Cleanup your cluster (the related machines will be automatically removed also) Cleanup is a special version of Destroy that will run and complete the on-delete-workflow before invoking Destroy.
Repeat the procdess for the lab1015 cluster