▲Understanding ReplicaSet vs. StatefulSet vs. DaemonSet vs. Deployments(abhisman.notion.site)
60 points by Abhisman 171 days ago | 4 comments
▲kevmo314 170 days ago
> 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.

▲smitelli 170 days ago
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.
▲ithkuil 170 days ago
Isn't that what we all are?
▲pphysch 170 days ago
Isn't that distributed systems in a nutshell?
▲nejsjsjsbsb 169 days ago
Node.js in a nutshell for sure
▲seivan 169 days ago
[dead]
▲Abhisman 170 days ago
Eh, dont you feel rewarded solving problems in general?
▲kevmo314 169 days ago
Can't say I feel like Kubernetes has solved more of my problems than it created.
▲melodyogonna 168 days ago
Are you doing datacenter-scale deployment and configuration?
▲kevmo314 168 days ago
Yup
▲melodyogonna 167 days ago
And you don't think Kubernetes solves a lot more problems than it creates? Very interesting, I wonder what you're comparing to.
▲draw_down 170 days ago
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▲ofrzeta 170 days ago
Doesn't seem to offer more insights than the Kubernetes docs.
▲LetMeLogin 170 days ago
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.

▲vanillax 170 days ago
Agree. Its more confusion. PVC / PV are native to k8s not something part of statefulsets. In fact you _probably_ only need to use Statefulsets for databases. Which is probably going to be abstracted away with Operators.
▲verdverm 170 days ago
It's more about roll forward/backward and services with a master+replica or leader election. That PVCs are common in stateful sets is more a symptom than the cause
▲vanillax 170 days ago
Yea for sure. Thats why I dropped the term database because thats the exact scenario ( master / replica ) where pod consistency naming,dns, network etc is important for StatefulSet.
▲MuffinFlavored 170 days ago
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,

▲wbl 170 days ago
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.
▲vanillax 170 days ago
You can map a PVC back to a pod without statefulset. You just need to create the PV and PVC and map it to a deployment.
▲null0pointer 170 days ago
Author is most likely farming credibility with blog spam.
▲sitkack 170 days ago
"Come on!"
▲Abhisman 167 days ago
"Maybe readers would want to read what I've written" - That's the approach that I had in mind when writing the article.
▲ 170 days ago
▲dgfitz 170 days ago
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.
▲Leo_Verto 170 days ago
Like it or not, containers are here to stay. They just make way too much sense as an atomic unit for delivering applicstions and really aren't that complicated.

Kubernetes is a whole nother beast though and while it introduces a ton of overhead, it can be useful at a certain organisational scale as an API definition for delivering services to other teams.

▲crabbone 170 days ago
This isn't about the state of container. It's about interactions between several containers (a group of containers is called a pod). Which, probably, doesn't make it better for you, but for the sake of correctness...
▲ 171 days ago