Schedule Typha for scaling to well-known nodes
Big picture
Schedule Typha to well-known nodes.
Value
By scheduling Typha to well-known nodes, you can reduce the number of nodes which expose Typha’s listen port.
Concepts
Typha
Typha is a Calico component which improves scalability and reduces the impact that large clusters may have on the Kubernetes API. Typha agents must accept connections from other agents on a fixed port.
As part of the Calico bootstrap infrastructure, Typha must be available before pod networking begins and uses host networking instead. It opens a port on the node it is scheduled on. By default, it can get scheduled to any node and opens TCP 5473.
How to
Tell if you have installed Typha
- Operator
- Manifest
Operator based installations always include Typha.
Check if the calico-typha
deployment exists in the kube-system
namespace.
kubectl get deployment -n kube-system calico-typha
Schedule Typha to well-known nodes
- Operator
- Manifest
You can use the Installation API to configure a node affinity for Typha pods. The operator supports both preferredDuringSchedulingIgnoredDuringExecution
and requiredDuringSchedulingIgnoredDuringExecution
options.
For example, to require the scheduler to place Typha on nodes with the label “typha=allowed”:
kind: Installation
apiVersion: operator.tigera.io/v1
metadata:
name: default
spec:
typhaAffinity:
nodeAffinity:
requiredDuringSchedulingIgnoredDuringExecution:
- matchExpressions:
- key: typha
operator: In
values:
- allowed