201–210 of 500 posts
In the coming years we will probably see a lot of complicated microservice architectures be replaced by well-designed and optimized Rust (and modern C++) monoliths that use simple replication to scale horizontally.
Replication and simple never belong in the same sentence. DNS which is one of the simplest replication systems I know of has its own complex failure modes.
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I wouldn't really agree with this since those machines don't share address spaces or directly attached busses. Better to say it's a warehouse-scale "service" provided by many machines which are aggregated in various ways.
I wonder though.. could you emulate a 20k-core VM with 100 terabytes of RAM on a DC? Ethernet is fast, you might be able to get in range of DRAM access with an RDMA setup. cache coherency would require some kind of crazy locking, but maybe you could do it with FPGAs attached to the RDMA controllers that implement something like Raft? it'd be kind of pointless and crash the second any machine in the cluster dies, but…
My joke fantasy startup is a cloud provider called one.computer where you just have a slider for the number of cores on your single instance, and it gives you a standard linux system that appears to have 10k cores. Most multithreaded software would absolutely trash the cache-coherency protocols and have poor performance, but it might be useful to easily turn embarrassingly parallel threaded map-reduces into multi-machine ones.
There was an article just yesterday about how Jane Street had developed an internal exchange way faster than any actual exchange by building it from the ground up, thinking about how the hardware works and how agents can interact with it.
Modern software like Slack or Twitter are just reinventing what IRC or BBS did in the past, and those were much leaner, more reliable and snappier than their modern counterparts, even if they didn't run at the same scale.
It wouldn't be surprising at all that you could build something equivalent to Twitter on just one beefy machine, maybe two for redundancy.
> colo cost + total server cost/(3 year) => $18,471/year Meanwhile the company I just left was spending more than this for dozens of kubernetes clusters on AWS before signing a single customer. Sometimes I wonder what I'm still doing in this industry.
Was it more than the salary of even a single software engineer?
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My friend mentioned this just before I published and I think that probably is the fastest largest thing you can get which would in some sense count as one machine. I haven't looked into it, but I wouldn't be surprised if they could get around the trickiest constraint, which is how many hard drives you can plug in to a non-mainframe machine for historical image storage. Definitely more expensive than just networking a…
> which is how many hard drives you can plug in to a non-mainframe machine for historical image storage. You would be surprised . First off, SSDs are denser than hard drives now if you're willing to spend $$$. Second, "plug in" doesn't necessarily mean "in the chassis". You can expand storage with external disk arrays in all sorts of ways. Everything from external PCI-e cages to SAS disk arrays, fibre channel, NVMe-o…
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Replication and simple never belong in the same sentence. DNS which is one of the simplest replication systems I know of has its own complex failure modes.
It can be outsourced complexity as in just using horizontally scalable database like Spanner, CockroachDB etc.
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If an inspector reviews your house and finds no issues, that is indeed evidence of absence.
But evidence is not necessarily proof.
This post reminds me of an experience I had in ~2005 while @ Hostway Chicago. Unsolicited story time: Prior to my joining the company Hostway had transitioned from handling all email in a dispersed fashion across shared hosting Linux boxes with sendmail et al, to a centralized "cluster" having disparate horizontally-scaled slices of edge-SMTP servers, delivery servers, POP3 servers, IMAP servers, and spam scanners. T…
I am both embarrassed and disappointed with the negativity this post has attracted. A litanny of "gotchas", where someone attempts to best the OP. What about x, y and z? It can't possibly scale. Twitter is so much more than this, etc. The OP isn't making the assertion that Twitter should replace their current system with a single large machine. The whole thread paints a picture of HN like it is full of a bunch of hal…
I must admit, as a bystander I'm torn here. I love that Tristan put out this post and made it so detailed with plenty of assumptions to cover. I also like to hear about possible issues and assumptions which the crowd calls out. Even naysayers can be helpful. I want both, but I don't want to crowd to go to far and kill the desire to produce this kind of content.
I think it's easy to have both. It's all about the tone of the responses.
For example, instead of "your assumptions are wrong, this would collapse because X" or "this is dumb because real Twitter does Y which yours doesn't handle," I think responses could be framed as:
"Wow, neat thought experiment! If I were to approach this same problem, I might make an allowance of more than 280 bytes of storage per tweet to allow for additional metadata that is probably needed to make everything work together; I wonder if that can be accommodated with an even beefier big computer?"
Or "What a great writeup of building a simplified Twitter! After the features you've accounted for, the next most important feature of Twitter for me personally is Y. What kinds of things would we have to do to stretch your idea to handle that? [or, I bet with the addition of X we could make that happen in this setup too!]"
I think many criticisms could be turned into constructive positive additions to the original article versus attacks against the idea of the article.