Oh no! It’s a _{1 2 3 4 5 6 …………………} ICOSAHEDRON!

Every episode seems to have one joke that really gets me. In this one it was Mariner stopping mid exclamation to make sure she correctly named the platonic solid that’s about to eat her.

If anyone actually manages to get Plasma Bigscreen working decently, please let me know how you did it. I was really excited when I first learned about it, but after considerable time tinkering, I gave up.

My first attempt was to install it on an old laptop. It boots up and looks good, but a large number of the built-in apps hang forever on their splash screen when you try to run them. I also couldn’t figure out how to customize what apps appear in the carousels on the homepage. I’m not sure if that’s because there truly is no way to do it or if the functionality is locked behind one of the apps that I can’t launch.

The Plasma Bigscreen website indicates that it was designed to run on a Raspberry Pi 4, so I gave in and bought one in hopes that using the preferred hardware would work better. I followed the provided links to the latest Manjaro build of Bigscreen (which is over a year old) and installed it on my pi. Unfortunately, that build apparently suffers from a bug that prevents you from even getting past the login screen on first boot up. I don’t remember the details, but I think it was some kind of “can’t log in without setting a password” / “can’t set a password until you log in” loop. Anyway, I found a forum post discussing the problem with no solutions found, so I gave up on the manjaro build.

My final attempt was to install an ordinary desktop Linux distribution on the pi and then use the package manager to install Plasma Bigscreen as an alternative desktop. This got me in, but there were still a bunch of broken apps. It was about this time that I also realized that the original Bigscreen concept seemed to lean heavily into voice control via Mycroft AI. Mycroft has gone through some major changes since the project launched, and I think these changes have resulted in basically all Mycroft related code in Plasma Bigscreen being broken. That may or may not be related to the other problems I had. I never got to experience a fully functional version of the software, so I have a hard time knowing what exactly is broken in what ways.

Anyway, that’s my experience with Plasma Bigscreen. I hope this doesn’t come across as hating on the project. It should be evident from the amount of effort put in that I really wanted it to work, but in the end I had to conclude that in its current state, it’s badly broken with no sign of improvement or repairs.

Out of curiosity, what software is normally being run on your clusters? Based on my reading, it seems like some companies run clusters for business purposes. E.g. an engineering company might use it for structural analysis of their designs, or a pharmaceutical company might simulate the interactions of new drugs. I assume in those cases they’ve bought a license for some kind of high-end software that’s been specifically written to run in a distributed environment. I also found references to some software libraries that are meant to support writing programs in this environment. I assume those are used more by academics who have a very specific question they want to answer (and may not have funding for commercial software) so they write their own code that’s hyper focused on their area of study.

Is that basically how it works, or have I misunderstood?

This actually came up in my research. Folding@Home is considered a “grid computer” According to Wikipedia:

Grid computing is distinguished from … cluster computing in that grid computers have each node set to perform a different task/application. Grid computers also tend to be more heterogeneous and geographically dispersed (thus not physically coupled) than cluster computers.

The primary performance disadvantage is that the various processors and local storage areas do not have high-speed connections. This arrangement is thus well-suited to applications in which multiple parallel computations can take place independently, without the need to communicate intermediate results between processors.

I’ll have to look a little more into the AI stuff. It was actually my first thought, but I wasn’t sure how far I’d get without GPUs. I think they’re pretty much required for Stablediffusion. I’m pretty sure even LLMs are trained on GPUs, but maybe response generation can be done without one.

I’m not sure what you’d want to run in a homelab that would use even 10 machines, but it could be fun to find out.

Oh yeah, this is absolutely a solution in search of a problem. It all started with the discovery that these old (but not ancient, most of them are intel 7th gen) computers were being auctioned off for like $20 a piece. From there I started trying to work backwards towards something I could do with them.

I was looking at HP mini PCs. The ones that were for sale used 7th gen i5s with a 35W TDP. They’re sold with a 65W power brick so presumably the whole system would never draw more than that. I could run a 16 node cluster flat out on a little over a kW, which is within the rating of a single residential circuit breaker. I certainly wouldn’t want to keep it running all the time, but it’s not like I’d have to get my electric system upgraded if I wanted to set one up and run it for a couple of hours as an experiment.

Nice 'course there’s an Emacs command for that.

Slightly off topic, but as long as we’re ranting about DNS…

Proxmox handles DNS for each container as a setting in the hypervisor. It’s not a bad way of simplifying things, but if, hypothetically, you didn’t know about that, then you could find yourself in a situation where you spend an entire afternoon trying every single one of the million different ways to edit DNS in Linux and getting increasingly frustrated because the IP gets overwritten every time you restart the container no matter what you do, until eventually you figure out that the solution is just like three clicks and a text entry box in the Proxmox GUI!

…Hypothetically, of course.

I agree that Mariner’s role in the episode was nothing but a running gag, but I have to point out what an exceptionally well written running gag it was, both in terms of her character and her character development over the course of the series.

Mariner’s behavior in this episode tells us two things about her. First, she’s the type of person who can get stabbed three times in a single day and (mostly) shrug it off. This isn’t really a surprise. She’s has always been both tough and resourceful, but she’s also impulsive and emotional which too often results in her messing things up. Not this time though, and that’s the second thing the episode tells us. Mariner is maturing. In past seasons a knife in her shoulder would have resulted in either a fight or a great deal of grandstanding about what a badass she is for not caring that she got stabbed, but not this time. This time Mariner knows that she’s only here to support her friend.

Mariner is the running gag in this episode because now, perhaps for the first time, she can handle being the running gag. She knows that this adventure is about Tendi, and she’s not going to derail it over a little thing like getting stabbed three times.

I seem to recall that this has to be accounted for when designing the support towers on particularly long bridges. According to a quick Google search, the most extreme example is the Akashi-Kaikyō bridge in Japan. The support towers are almost 3.5 inches farther apart at the top than they are at the bottom.

Also FYI, the word “level” generally refers to things laying perfectly flat. The word “plumb” refers to thing standing perfectly upright, which is why some jokers in the comments are giving you a hard time, despite what you meant being fairly obvious.

The SCP wiki is always a fun place to lose a couple of hours. Here’s how they describe themselves:

The SCP Wiki is a collaborative speculative fiction website about the SCP Foundation, a secretive organization that contains anomalous or supernatural items and entities away from the eyes of the public.

And here’s an example page about a moth with mind control powers