How To Setup Highly Available Kubernetes Clusters And Applications?

What is high availability? How does high availability architecture look like? How to set up highly available Kubernetes clusters and applications?

#highavailability #ha #kubernetes #k8s

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▬▬▬▬▬▬ Timecodes ⏱ ▬▬▬▬▬▬
00:00 What is high availability?
01:36 Main Kubernetes components
02:11 Single-node control plane
03:29 Two nodes control plane
05:21 Three or more nodes control plane
08:23 External load balancer
10:02 Data centers or zones
13:24 Combining control plane and worker nodes
14:23 Separate control plane and worker nodes
15:00 Highly-available applications

[DevOpsToolkit]

Is your system highly available (HA)? If it is, how did you architect it?

[cloud-jiqm]

Unbelievable how simply you explained this complex subject and made it easy to understand, thanks you!

[mohammadbagheri]

Just wow, you described any tiny aspect of it in just 17mins!

You earn a subscribe!

[javisartdesign]

Great explanation! Quorum, leader election, raft, gossip, etc.. all these concepts, protocols and patterns must be understood by anybody who wants to build distributed systems. Another topics such as CAP theorem, two phase commit, ACID transactions are the foundations of these concepts.

[vback]

Thank you for making this as simple as ABC. Wow! You are great!

[mikegbow]

Your videos are helping me a lot with really understanding Kubernetes and containerization. Thank you!

[miloslavhantl]

Very nice explained how to accomplish and what aspects need to be aware. Thank you a lot Victor !

[deap]

Victor, thanks for following up with this wonderful piece after our last convo. Impressed, brilliant content, you are close to your fans and one feels every second that you have IRL exp and not just reframing some other tutorials, don't know any better Youtuber out there. Now, I'm just thinking how to get multi zones without the big 3 haha. But yeah, there is nobody. I mean just look what killer bare machines you get, setup in 90sec or so on the fly at Equinix, what you pay. And tbh, I"ll setup an as-well-featured-k8s-cluster on bare metal with all bells an whistles faster, better and easier to manage than on any cloud provider, and yes with seamless k8s updates. Just without multi zones but yeah. Maybe I`ll find a way some day haha.

[JackReacher]

1:48
Is that the same Engineer I know who would say "If you don't know kubectl, what are you doing here in an eksctl video" ? 😂
btw Another one of those good video.

[robarros]

the new k0s project is really cool for kubernetes environments

[quackycoder]

Really interesting and informative! Please keep sharing your knowledge! Thanks!:)

[ghadeerelsalhawy]

Thank you so much for the explanation.

[anshuman]

Great video. Good work. Could add a animation to show HA on 3 servers works and how to set up cluster and quorum in brief

[aliakbarhemmati]

I think we should differentiate etcd nodes from other control plane nodes. Yes, if we have two etcd nodes we can not call it HA. But what about api server? Because it is stateless, I think having more than one instance is HA for it.

[fenarRH]

+ Notes from experiences form from wrong expectations of k8s consumers: Etcd uses the Raft consensus algorithm to replicate requests among members and reach agreement. Consensus performance, especially commit latency, is limited by two physical constraints: network IO latency and disk IO latency. If your cp nodes spread across multiple locations, the general approach is to keep latency <5ms, in distance terms (speed of light in fibre +avg eq latency fiber x duration) is <100miles between those dc(s) you land your cp nodes. If you are dreaming long living giant k8s cluster(s) with cp nodes all around the world that is likely not to fly, besides thats not what k8s for anyways.

[ajk]

doesn't only etcd require to be minimum 3? in that case only 2 control planes are required for HA, if there are external 3 etcds. please clarify.

[illiakailli]

thanks for a nice explanation! it really helps to start thinking about important things. Have a question: is it legitimate to state with such certainty 'rules of thumb' without knowing specifically which clusters we are talking about? You've mentioned speed degradation when cluster spans multiple geographical regions, but how important this speed for each specific cluster? For example, if this is a non-sharded database cluster, then fast replication might be important, but what if its sharded? what if it doesn't need to transfer much data across nodes and just needs to send packets to maintain quorum? My point is that it really depends on your specific app, business constraints, budget and all that jazz. Also, by saying that you need to host database somewhere else - you really just shifting responsibility to some other team: they will have to solve same problems you outlined.

[kiranyadav]

Hi victor

Thanks for a detailed explanation. And my requirement exactly matching your solution. But I am unable find enough resources to help this solution deployment . So can you please share me any link or solution where your solution is practically implemented or any supporting architecture or documentation which will help me to build this setup .

[shukhrate]

1 comment. If adding more replicas it is Scale Out, if adding more CPU/RAM/Changing instance type - Scale Up

[mulshiwaters]

Instead if Scale-UP we should use Scale-OUT as we are talking about Horizontal Scalability !