I want to know the recommendation set for pod size. I.e. when to put application within pod or at what size it will be better to use machine itself in place of pod.
Ex. when to think of coming out of k8s and used as external service for some application, when pod required 8GB or 16GB or 32GB? Same for CPU intensive.
Because if pod required 16GB or 16 CPU and we have a machine/node of the same size then I think there is no sense of running pod on that machine. If we run in that scenario then it will be like we will having 10 pods and which required 8 Nodes.
Hopes you understand my concern.
So if some one have some recommendation for that then please share your thoughts on that. Some references will be more better.
Recommendation for ideal range:
etc.
Running 16cpu/16gb pod on 16cpu/16gb machine is normal. Why not? You think of pods to be tiny but there is no such requirement. Pods can be gigantic, there is no issue with that. Remember container is just a process on a node, why you refuse to run a fat process on a fat node? Kubernetes adds very nice orchestration level to containers, why not make use of it?
There is no such thing as a universal or recommended pod size. Asking for recommended pod size is the same as asking for a recommended size for VM or bare metal server. It is totally up to your application. If your application requires 16 or 64 GB of RAM - this is the recommended size for you, you see?
Regarding pods to nodes ratio - current upper limit of Kubernetes is 110 pods per node. Everything below that watermark is fine. The only thing is that recommended master node size increases with total number of pods. If you have like 1000 pods - you go with small to medium size master nodes. If you have over 10 000 pods - you should increase your master nodes size.
Regarding statefulness - stateless application generally survive better. But often state also should be stored somewhere and stored reliably. So if you plan your application as a set of microservices - create as much stateless apps you can and as few stateful as you can. Ideally, only the relational databases should be truly stateful.