In this section, you will learn how to configure multiple node pools for a Konvoy cluster. Node pools allow the cluster administrator to use different configurations for different sets of worker nodes in a heterogeneous environment.
Configure multiple node pools for an on-premises cluster
The following example will show you how to configure multiple node pools for an on-premises Konvoy cluster.
Assume that the cluster administrator wants to have a dedicated host for the monitoring pipeline (such as Prometheus), because it is very critical to the entire cluster and should not be interfered with by any other pods.
Since this is an on-premises deployment, you need to specify the Ansible inventory file (such as
inventory.yaml) manually, as in the following:
control-plane: hosts: 10.0.194.142: ansible_host: 10.0.194.142 10.0.198.130: ansible_host: 10.0.198.130 10.0.200.148: ansible_host: 10.0.200.148 node: hosts: 10.0.130.168: ansible_host: 10.0.130.168 node_pool: worker 10.0.133.221: ansible_host: 10.0.133.221 node_pool: worker 10.0.139.120: ansible_host: 10.0.139.120 node_pool: worker 10.0.131.62: ansible_host: 10.0.131.62 node_pool: monitoring all: vars: version: v1beta1 order: sorted ansible_user: "centos" ansible_port: 22
Notice that in the
nodes section, each host has a string attribute called
This field specifies the node pool to which a host belongs.
In this case, node
10.0.131.62 belongs to node pool
monitoring, and the rest of the nodes belong to node pool
monitoring node pool is dedicated for the monitoring pipeline, you need to taint the nodes in that node pool so that regular pods will not be scheduled on those hosts.
You may also want to add some special labels to the nodes in the node pool so that users can use node selectors to schedule pods on those nodes.
To configure the taints and labels, edit the cluster configuration file (such as
cluster.yaml) like the following:
kind: ClusterConfiguration apiVersion: konvoy.mesosphere.io/v1beta2 spec: nodePools: - name: worker - name: monitoring labels: - key: dedicated value: monitoring taints: - key: dedicated value: monitoring effect: NoExecute
The above configuration will add the label
dedicated: monitoring and apply the
dedicated: monitoring taint to all nodes in the
monitoring node pool.
Note that all node pools specified in the inventory file (such as
inventory.yaml) should have a corresponding entry in the
spec.nodePools section of
If not, the validation will fail.
Then, configure the Prometheus addon like the following so that it will be scheduled on the dedicated node (such as
monitoring node pool).
- name: prometheus enabled: true values: | prometheus: prometheusSpec: tolerations: - key: "dedicated" operator: "Equal" value: "monitoring" effect: "NoExecute" nodeSelector: dedicated: "monitoring"
Once all configurations are complete, run
konvoy up to install the cluster.
The labels and taints will be applied accordingly to the corresponding nodes. Prometheus will be scheduled on the dedicated node for monitoring purposes.
During the install process, all of the nodes will also be labeled with
<node_pool corresponds to the value specified in the
node_pool property is empty, the control-plane node(s) will be automatically labeled with
konvoy.mesosphere.com/node_pool=konvoy.mesosphere.com_control-plane, similarly the worker nodes will be labeled with
Configure multiple node pools for as AWS cluster
Configuring node pools for AWS deployment is mostly the same as on-premises deployment; however, you do not need to configure the inventory file manually, as it is automatically generated by the AWS provisioner.
You can add node pools to the
ClusterProvisioner configuration like the following:
kind: ClusterProvisioner apiVersion: konvoy.mesosphere.io/v1beta2 spec: nodePools: - name: worker count: 3 machine: rootVolumeSize: 80 rootVolumeType: gp2 imagefsVolumeEnabled: true imagefsVolumeSize: 160 imagefsVolumeType: gp2 imagefsVolumeDevice: xvdb type: m4.4xlarge - name: control-plane controlPlane: true count: 3 machine: rootVolumeSize: 80 rootVolumeType: gp2 imagefsVolumeEnabled: true imagefsVolumeSize: 160 imagefsVolumeType: gp2 imagefsVolumeDevice: xvdb type: i3.xlarge - name: monitoring count: 1 machine: rootVolumeSize: 80 rootVolumeType: gp2 type: m4.4xlarge
The rest of the configuration will be the same as that in the on-premises case.