I have a deployment with one pod with my custom image. After executing kubectl create -f deployment.yaml, this pod becomes running. I see that everything is fine and it has "running" state in kubectl's output. But, i have one initialization script to start Apache Tomcat, it takes around 40-45 seconds to execute it and up server inside.

I also have load balancer deployment with nginx. Nginx redirects incoming requests to Apache Tomcat via proxy_pass. When i scale my deployment for 2 replicas and shut down one of them, sometimes application becomes stuck and freezing.

I feel that load balancing by k8s works not correctly, k8s is trying to use pod, which is initializing by script right now.

How can i tell k8s that pod in deployment hasn't been initialized and not to use it until it becomes totally up?

CodePudding user response：

If I understand correctly mostly your problem is related to the application not being ready to accept requests because your initialization script hasn’t finished.

For that situation, you can easily setup different types of probes, such as liveliness and readiness. Such a solution would be useful, as your application wouldn’t be considered ready to accept requests unless the whole pod would start up and signal that it is alive.

Here you can read more about it: https://kubernetes.io/docs/tasks/configure-pod-container/configure-liveness-readiness-startup-probes/