Socket IO in Kubernetes keeps disconnecting

Question

I'd like to launch a clustered Socket IO application in Kubernetes. When I create a service (whether NodePort or LoadBalancer) the client application keeps getting disconnected and it reconnects again with the following logs:

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and this happens rapidly.

However, when I connect to a single Pod directly, the problem goes away and the connection becomes stable.

How I am creating the service is by the following command:

kubectl expose deployment xxx --type=LoadBalancer --port=80 --target-port=3000

I know that something such as a KeepAlive or Timeout configuration is missing in the service, but how can I add those or better said properly configure the service for Socket IO?

score 3 · Accepted Answer · answered Jul 07 '22 at 18:35

You can use the sessionAffinity: ClientIP, which will manage the session from K8s service.

kind: Service
apiVersion: v1
metadata:
  name: example
spec:
  selector:
    app: example
  ports:
  - name: http
    protocol: TCP
    port: 80
    targetPort: 80
  sessionAffinity: ClientIP
  sessionAffinityConfig:
    clientIP:
      timeoutSeconds: 1800

just for ref : Does the ws websocket server library requires sticky session when it is used behind a load balancer?

Socket IO in Kubernetes keeps disconnecting

1 Answers1