About node pools

Anode pool is a group of nodes within a cluster that all have the same configuration.Typically, you define separate node pools when you have pods with differing resource requirements.For example, theapigee-cassandra pods require persistent storage, whilethe other Apigee hybrid pods do not.

This topic discusses how to configure dedicated node pools for a hybrid installation.

Using the default nodeSelectors

The best practice is to set up two dedicated node pools: one for the Cassandra pods and one for all the other runtime pods. Using defaultnodeSelector configurations, the installer will assign the Cassandra pods to astateful node pool namedapigee-data and all the other pods to astateless node pool namedapigee-runtime. All you have to do is create node pools with these names, and Apigee hybrid handles the pod scheduling details for you:

Following is the defaultnodeSelector configuration. TheapigeeData property specifies a node pool for the Cassandra pods. TheapigeeRuntime specifies the node pool for all the other pods. You can override these default settings in your overrides file, as explained later in this topic:

nodeSelector:  requiredForScheduling: false  apigeeRuntime:    key: "cloud.google.com/gke-nodepool"    value: "apigee-runtime"  apigeeData:    key: "cloud.google.com/gke-nodepool"    value: "apigee-data"

Again, to ensure your pods are scheduled on the correct nodes, all you have to do is create two node pools with the namesapigee-data andapigee-runtime.

The requiredForScheduling property

ThenodeSelector config section has a property calledrequiredForScheduling:

nodeSelector:requiredForScheduling: false  apigeeRuntime:    key: "cloud.google.com/gke-nodepool"    value: "apigee-runtime"  apigeeData:    key: "cloud.google.com/gke-nodepool"    value: "apigee-data"

If set tofalse (the default), underlying pods will be scheduled whether or not node pools are defined with the required names. This means that if you forget to create node pools or if you accidentally name a node pool other thanapigee-runtime orapigee-data, the hybrid runtime installation will succeed. Kuberneteswill decide where to run your pods.

If you setrequiredForScheduling totrue, the installation will fail unless there are node pools that match the configurednodeSelector keys and values.

nodeSelector:  requiredForScheduling: false  apigeeRuntime:    key: "cloud.google.com/gke-nodepool"    value: "my-runtime-pool"  apigeeData:    key: "cloud.google.com/gke-nodepool"    value: "my-cassandra-pool"

runtime:  nodeSelector:    key: cloud.google.com/gke-nodepool    value: apigee-custom

cloud.google.com/gke-nodepool=THE_NODE_POOL_NAME

As long as you create node pools namedapigee-data andapigee-runtime, no further configuration is required. If you want to use custom node names, seeUsing custom node pool names.

Anthos node pool configuration

Apigee hybrid currently is only supported on Anthos 1.1.1. This version of Anthos does not support the node pool feature; therefore, you must manually label the worker nodes as explained below. Perform the following steps once your hybrid cluster is up and running:

1. Run the following command to get a list of the worker nodes in your cluster:

   kubectl -n apigee get nodes

   Example output:

   NAME                   STATUS   ROLES    AGE     VERSIONapigee-092d639a-4hqt   Ready    <none>   7d      v1.14.6-gke.2apigee-092d639a-ffd0   Ready    <none>   7d      v1.14.6-gke.2apigee-109b55fc-5tjf   Ready    <none>   7d      v1.14.6-gke.2apigee-c2a9203a-8h27   Ready    <none>   7d      v1.14.6-gke.2apigee-c70aedae-t366   Ready    <none>   7d      v1.14.6-gke.2apigee-d349e89b-hv2b   Ready    <none>   7d      v1.14.6-gke.2

2. Label each node to differentiate between runtime nodes and data nodes.Note: Be sure to choose the nodes so that they are equally distributed among availability zones (AZs).

   Use this command to label the nodes:

   kubectl label nodeNODE_NAMEKEY=VALUE

   For example:

   $ kubectl label node apigee-092d639a-4hqt apigee.com/apigee-nodepool=apigee-runtime$ kubectl label node apigee-092d639a-ffd0 apigee.com/apigee-nodepool=apigee-runtime$ kubectl label node apigee-109b55fc-5tjf apigee.com/apigee-nodepool=apigee-runtime$ kubectl label node apigee-c2a9203a-8h27 apigee.com/apigee-nodepool=apigee-data$ kubectl label node apigee-c70aedae-t366 apigee.com/apigee-nodepool=apigee-data$ kubectl label node apigee-d349e89b-hv2b apigee.com/apigee-nodepool=apigee-data

Overriding the node pool for specific components on Anthos GKE

You can also override node pool configurations at the individual component level for an Anthos GKE installation. For example, the following configuration assigns the node pool with the valueapigee-custom to theruntime component:

runtime:  nodeSelector:    key: apigee.com/apigee-nodepool    value: apigee-custom