Don't worry, it's not just you. I learn concepts by building and tinkering (and reading specifications), so you'd think I'm a target market. But when I wanted to get some hands on experience with a cluster file system, for a job, I spun up a cluster of 5 vms on... my normal computer.
4 seems like a very useless number to me. 4 raspis is more expensive and less useful than a used dual xeon on ebay. I could imagine maybe there's a use for something with 16 slots? or at least 8? But I don't get these cluster boards (or, for that matter, storage enclosures!) which presume I can do something fundamentally different with 4 small computes than 1.
The original Turing Pi had 7 slots (wish it had even more!). I do feel that was better, because it really forces you to manage it as a cluster.
Spinning up VMs is sort of fine, but they don't have quite the performance or management characteristics of a real cluster. The network is slow, the nodes individually are not very powerful, you have to work out how to image each physical machine, nodes break or have I/O errors, ...
> maybe there's a use for something with 16 slots? or at least 8?
You can always connect 2 or 4 of these together.
But I understand what you mean. A project I want to build one day, when I have the time and learn ethernet interfacing through PCB's is to build a single board cluster of Octavo SoM modules. They are individually inexpensive and it'd be relatively easy to build a board with a dozen of them connected to a switch chip.
Yeah exactly, my first thought is that a normal multicore PC is going to be not just more powerful, but more power efficient and cost efficient. It's a fun idea but I wouldn't be interested unless they publish some comparisons.
Basically everything here can be done on a single multicore computer (which is already a distributed system in many respects):
more powerful in most cases - yes. distributed - no.
learning about doing HA/Scale out via distributed systems is a really valuable skill, and projects like these make it sooo much more real, beyond even just basic networking.
4 seems like a very useless number to me. 4 raspis is more expensive and less useful than a used dual xeon on ebay. I could imagine maybe there's a use for something with 16 slots? or at least 8? But I don't get these cluster boards (or, for that matter, storage enclosures!) which presume I can do something fundamentally different with 4 small computes than 1.