Manage worker node pools
Flex cluster plans introduces the concept of worker node pools.
The "Worker Node Pools" tab in the cluster creation/edit form allows you to manage the compute instances of your cluster.
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You are allowed to customize the number of vCPUs, amount of Memory, amount of Persistent Storage and number of nodes for a worker node pool.
The button "Add Worker Node Pool" opens the following form:
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The following restrictions apply:
- You could specify between 1 and 9 worker node pools.
- You could specify the node pools name only during creation. It could not be changed after that. For this you could add a new pool and remove the old one.
- Allowed values for "Node vCPU" are: 1, 2, 4, 8, 16, 32, 64.
- Allowed values for "Node Memory" are: 4, 8, 16, 32, 64, 128, 256, 512.
- Allowed values for "Node Storage" are: between 25 and 500.
- For non-upgraded clusters, only the number of nodes for existing node pools could be modified. Adding pools, deleting pools and modifying CPU/Memory/Storage/Node-taints/Node-labels is not allowed.
- Clusters created before 1st of June were migrated to flex cluster plans. During the migration, they were assigned one node pool with the name of the T-shirt size plan they used during creation. You are not allowed to edit the properties of this pool. Please create a new one.
Vertical Scaling
Vertical scaling can be triggered by editing the "Worker Node Pools" tab.
Here are few important conditions that need to be met to trigger a vertical scaling operation:
Only existing pools must be modified.
The creation of a new pool or the deletion of a pool, in the same edit operation, will lead to the standard update process which will not trigger the creation of additional nodes.
Only a combination of the following parameters must be present in the update operation: (cpu, memory, storage, node-taints and node-labels)
Any modification of the worker node count in a pool, in the same edit operation, will lead to the standard update process which will not trigger the creation of additional nodes. In other words, in order to have a vertical scaling scenario, the number of worker nodes must remain the same.
Any other modification such as insecure-registries or email owner, in the same edit operation, will lead to the standard update process which will not trigger the creation of additional nodes.
During a vertical scaling operation, all the nodes will be drained one time.
Update scenario | Vertical scaling ? | Horizontal scaling ? |
---|---|---|
Changing node-labels | ✅ | 🚫 |
Changing node-taints | ✅ | 🚫 |
Changing storage | ✅ | 🚫 |
Changing memory | ✅ | 🚫 |
Changing cpu | ✅ | 🚫 |
Increasing count AND edit of (cpu/memory/storage/taints/labels) | 🚫 | ✅ |
Decreasing count AND edit of (cpu/memory/storage/taints/labels) | 🚫 | ✅ |
Adding new pool AND existing pools remain unchanged | 🚫 | ✅ |
Change of worker count (only) | 🚫 | ✅ |
Adding new node pool AND edit of (cpu/memory/storage/taints/labels) | 🚫 | ✅ |
Removing 1 node pool | 🚫 | ✅ |
Removing 1 node pool AND edit of (cpu/memory/storage/taints/labels) | 🚫 | ✅ |
Notes:
- Horizontal scaling operation (also called standard operation) will trigger the drain of all the worker nodes (one at a time) except in one condition. If only the worker node count is changed or a new pool is added, existing nodes won't be drained.