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Let's Build a 28-Core Raspberry Pi Cluster

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Re: Let's Build a 28-Core Raspberry Pi Cluster

#81

Post by fock »

tra3 wrote: post #43
ArchD wrote: post #40

What's the actual use case for rpi clusters like this? If the goal is to learn docker or k8s using a realistic setup involving multiple machines, can't it be achieved by using multiple VMs on one physical desktop instead of using the cluster? The 7-node cluster has only 7GB RAM in total, which is not too much to ask on a desktop. I don't know what people do with rpi clusters and I'm honestly puzzled why people bother…

The use case is tinkering. I think it’s pretty sweet to be able to build a super low cost cluster like this. Play with docker, k8s etc.

if you only want to play with software, VMs are a lot easier though (and you got to learn the basics of the VMs)

Re: Let's Build a 28-Core Raspberry Pi Cluster

#83

Post by dumb1224 »

fock wrote: post #79

"This build is for you if you:" ahem, for 600 dollars I get a fine computer which can host all the kubernets and docker I ever want in a nice formfactor... I mean, it's cool and all, but effectively utterly useless except for the blinking lights.

Very cool work! I wonder the same, for a 'cluster' I'm expecting performance and large memory for example for scientific computing. Other than that I couldn't think of any other use cases. If anyone could enlighten me? Cheers

Re: Let's Build a 28-Core Raspberry Pi Cluster

#84

Post by asa4akj »

ArchD wrote: post #40

What's the actual use case for rpi clusters like this? If the goal is to learn docker or k8s using a realistic setup involving multiple machines, can't it be achieved by using multiple VMs on one physical desktop instead of using the cluster? The 7-node cluster has only 7GB RAM in total, which is not too much to ask on a desktop. I don't know what people do with rpi clusters and I'm honestly puzzled why people bother…

You see, there is a big emotional difference in unplugging a network cable of a node, and see your cluster keep going and re-routing traffic compared to clicking on a "shut down VM" button.

These small emotional things end up making you more interested, and keeps you going in projects. It's the little things! After all this is just for playing around, if you wanted any performance, a single machine would give you more.

Re: Let's Build a 28-Core Raspberry Pi Cluster

#86

Post by sdgjhfdlkgjhdf »

mvanbaak wrote: post #82

People wanting to torture themselves with k8s at home ... I still dont understand why.

I actually have a k3s cluster running my blog/a few services. It just works, really, and so far it has been zero maintenance, zero downtime, apart from the large upfront investment (one weekend). Most importantly it was a great learning experience.

Re: Let's Build a 28-Core Raspberry Pi Cluster

#87

Post by noir_lord »

dumb1224 wrote: post #83
fock wrote: post #79

"This build is for you if you:" ahem, for 600 dollars I get a fine computer which can host all the kubernets and docker I ever want in a nice formfactor... I mean, it's cool and all, but effectively utterly useless except for the blinking lights.

Very cool work! I wonder the same, for a 'cluster' I'm expecting performance and large memory for example for scientific computing. Other than that I couldn't think of any other use cases. If anyone could enlighten me? Cheers

They built a multi-thousand pi cluster to test the SMP and configuration stuff before running it on a super computer.

Virtualising thousands of CPUs on a single machine is still not trivial.

Never mind simulating real world network issues.

https://www.bitscope.com/blog/FM/?p=GF19A

Re: Let's Build a 28-Core Raspberry Pi Cluster

#88

Post by hestefisk »

ikaruswill wrote: post #23

Hello, original author here. I saw a bunch of traffic from Hacker News and decided to drop by. Thanks for sharing it here! I'd be happy to answer any questions.

Very nice work. Super geeky. I would love running a Plan9 cluster on this setup. Any thoughts on trying it out?

Re: Let's Build a 28-Core Raspberry Pi Cluster

#89

Post by aaronax »

mvanbaak wrote: post #82

People wanting to torture themselves with k8s at home ... I still dont understand why.

Imagine that the jobs you are interested in want to see some k8s experience. Either you teach it to yourself at home or you justify implementing it at your current job (resume driven development basically).

Re: Let's Build a 28-Core Raspberry Pi Cluster

#90

Post by tssva »

magicalhippo wrote: post #7

So I was toying with the idea of something similar. I'm a programmer and not a sysadmin, but I've dabbled with Docker and had a specific use-case. But so far I've not come further than this: how to deal with the host OS? Like, I don't want to log into N computers and manually run "sudo apt update" etc. I want them to run the same OS but with slightly different configurations. Network booting via PXE seems to be the b…

If the concern is initial provisioning I handle that by using Ubuntu server for my RPi cluster. Ubuntu server for the RPi supports using cloud-init for initial configuration of the server.

In my case I only have 2 different configurations, controller node and worker node. When deploying a new worker node I use a single digit line count shell script to produce the cloud-init files for that node from my template. Basically the only changes between worker nodes are the host name and static IP assigned. I then copy the resulting files to the FAT partition of the boot sdcard.

Someday I might replace this with network booting and something like ansible but for now this is an easy solution and handles 99% of my particular needs.

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