Understanding ReplicaSet vs. StatefulSet vs. DaemonSet vs. Deployments

> Understanding the nuances and distinctions between these key concepts becomes crucial as you navigate the complex — yet rewarding — waters of container orchestration.

Can't say I've ever felt rewarded for using Kubernetes, literally or metaphorically.

Re: Understanding ReplicaSet vs. StatefulSet vs. DaemonSet vs. Deployments

#7

Post by MuffinFlavored » Mon, Jan 06, 2025, 2:30 PM UTC

LetMeLogin wrote: post #5

ofrzeta wrote: post #3

Doesn't seem to offer more insights than the Kubernetes docs.

Totally. Plus it's misguiding readers with different functionality and use cases. For example "Persistent Storage: StatefulSets provide persistent storage to their pods through Kubernetes PersistentVolumes". The thing is that STS doesn't do that. That's actually in POD definition.

I had no idea... probably shows I haven't hit an advanced enough use case.

> why isn't a statefulset just a deployment/pod with PVC mounted?

* StatefulSets provide predictable pod names and hostnames (pod-0, pod-1)

* StatefulSets handle pods sequentially (0→1→2), ensuring proper cluster initialization.

* StatefulSets maintain a consistent pod-to-PVC mapping even after pod rescheduling.

* StatefulSets delete pods in reverse order,

Re: Understanding ReplicaSet vs. StatefulSet vs. DaemonSet vs. Deployments

#8

Post by smitelli » Mon, Jan 06, 2025, 3:35 PM UTC

kevmo314 wrote: post #6

> Understanding the nuances and distinctions between these key concepts becomes crucial as you navigate the complex — yet rewarding — waters of container orchestration. Can't say I've ever felt rewarded for using Kubernetes, literally or metaphorically.

Early on I heard the k8s controller ecosystem described as “a half dozen concurrent `while true` loops all fighting with each other.” Can’t say I disagree.

Re: Understanding ReplicaSet vs. StatefulSet vs. DaemonSet vs. Deployments

#9

Post by wbl » Mon, Jan 06, 2025, 3:43 PM UTC

MuffinFlavored wrote: post #7

LetMeLogin wrote: post #5

Earlier quoted context omitted.

Totally. Plus it's misguiding readers with different functionality and use cases. For example "Persistent Storage: StatefulSets provide persistent storage to their pods through Kubernetes PersistentVolumes". The thing is that STS doesn't do that. That's actually in POD definition.

I had no idea... probably shows I haven't hit an advanced enough use case. > why isn't a statefulset just a deployment/pod with PVC mounted? * StatefulSets provide predictable pod names and hostnames (pod-0, pod-1) * StatefulSets handle pods sequentially (0→1→2), ensuring proper cluster initialization. * StatefulSets maintain a consistent pod-to-PVC mapping even after pod rescheduling. * StatefulSets delete pods in r…

You can look at the structure in TFA to see this. The only discussion of the volume mounting is in the pod template, not the Stateful Set itself.

Re: Understanding ReplicaSet vs. StatefulSet vs. DaemonSet vs. Deployments

#10

Post by dgfitz » Mon, Jan 06, 2025, 3:47 PM UTC

I hope I've avoided containers enough to let this phase pass by. Formalizing vocabulary around the different states of a container makes me want to throw up my hands in a Seinfeld "come one" motion.