About node pools
A node 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, the apigee-cassandra pods require persistent storage, while
the 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 default
nodeSelector configurations, the
installer will assign the Cassandra pods to a stateful node pool named apigee-data and all
the other pods to a stateless node pool named apigee-runtime. All you have to do is
create node pools with these names, and Apigee hybrid handles the pod scheduling details
for you:
| Default node pool name | Description |
|---|---|
apigee-data |
A stateful node pool. |
apigee-runtime |
A stateless node pool. |
Following is the default nodeSelector configuration. The apigeeData
property specifies a node pool for the Cassandra pods. The apigeeRuntime 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: true
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 names apigee-data and apigee-runtime.
The requiredForScheduling property
The nodeSelector config section has a property called
requiredForScheduling:
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 to false, 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 than apigee-runtime or
apigee-data, the hybrid runtime installation will succeed. Kubernetes
will decide where to run your pods.
If you set requiredForScheduling to true (the default), the installation will fail
unless there are node pools that match the configured nodeSelector keys and values.
Using custom node pool names
If you don't want to use node pools with the default names, you can create node pools with
custom names and specify those names in the
nodeSelector stanza. For example, the following configuration assigns the
Cassandra pods to the pool named my-cassandra-pool and all other pods to the pool
named my-runtime-pool:
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"
Overriding the node pool for specific components on GKE
You can also override node pool configurations
at the individual component level. For example, the following configuration assigns
the node pool with the value
apigee-custom to the runtime component:
runtime:
nodeSelector:
key: cloud.google.com/gke-nodepool
value: apigee-custom
You can specify a custom node pool on any of these components:
istiomartsynchronizerruntimecassandraudcalogger
GKE node pool configuration
In GKE, node pools must have a unique name that you provide when you create the pools, and GKE automatically labels each node with the following:
cloud.google.com/gke-nodepool=THE_NODE_POOL_NAME
As long as you create node pools named apigee-data and apigee-runtime,
no further configuration is required. If you want to use custom node names, see
Using 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:
- 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 VERSION apigee-092d639a-4hqt Ready <none> 7d v1.14.6-gke.2 apigee-092d639a-ffd0 Ready <none> 7d v1.14.6-gke.2 apigee-109b55fc-5tjf Ready <none> 7d v1.14.6-gke.2 apigee-c2a9203a-8h27 Ready <none> 7d v1.14.6-gke.2 apigee-c70aedae-t366 Ready <none> 7d v1.14.6-gke.2 apigee-d349e89b-hv2b Ready <none> 7d v1.14.6-gke.2
- Label each node to differentiate between runtime nodes and data nodes.
Use this command to label the nodes:
kubectl label node NODE_NAME KEY=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 value
apigee-custom to the runtime component:
runtime:
nodeSelector:
key: apigee.com/apigee-nodepool
value: apigee-custom
You can specify a custom node pool on any of these components:
istiomartsynchronizerruntimecassandraudcalogger