5 ms·

How did this make it to the number two spot on HackerNews?

by ppeetteerr 5y ago

deleted 5y ago
[deleted]
deleted 5y ago
[deleted]
ok_coo 5y ago
IMHO, it's better than a deluge of political posts. I don't mind reading about politics but I come to HN to read about tech. We can go elsewhere to get whatever politics we desire.
dreyfan 5y ago
Broadly speaking people on HN have no clue how to setup a performant httpd/app server and are impressed by abysmal performance/cost metrics like this or the MangaDex post. Everything these days is obscured through multiple layers of SaaS offerings and unnecessary bloat like kubernetes. ~10k rps (it was concurrent connections but close enough) was state of the art in 1999. Now 22 years later ~50 rps is somehow impressive.
- watermelon0 5y ago
  I would guess this is close to a default Apache + mod_wsgi setup, and this is one of the easiest way of hosting Python web apps, so basically achievable by anyone on HN. I assume (based on 180 req/s for static page) that he is using mpm_prefork, where each Apache child handles a single connection. If he switched to mpm_event, which uses event loop like nginx, ~10k rps should easily be achievable, but I don't think WSGI would work with that.
  - mark_mcnally_je 5y ago
    Yeah it's all default apache + mod_wsgi. This is also my first Django setup and I made it over-complicated as a learning exercise. mpm_event is something I have not heard of before, thanks for bringing that to my attention.
- reilly3000 5y ago
  In my opinion it isn’t so much of a lost art or lamentable accretion of useless abstractions, but an increase in the scope of what web apps do these days. Most of us aren’t working on static sites or simple CMS publishing- those are a solved problem. Instead we’re building mobile banks, diagnostic systems, software tooling, 3D games, and shopping malls. The complexity is inherent in the maturity of the web and it’s many uses, as well as its global scale. Hugs of death are rare these days thanks to better architecture and infrastructure, even though the scale of users has grown 100X. Yes there are wildly unnecessary abstractions that are used for small sites/apps, but I would contend they are artifacts of someone who it’s trying to learn something new, and/or get promoted. I have no problem with the former.
- ppeetteerr 5y ago
  The author provides no information other than to say it's an Apache + Django setup. That's pretty bare-bones and is part of most tutorials online.
- Zababa 5y ago
  > ~10k rps (it was concurrent connections but close enough) was state of the art in 1999. Now 22 years later ~50 rps is somehow impressive. I honestly don't understand how that can be true. I'm not suggesting you're lying of course, but when you put it this way it's almost like people are actively trying to slow their programs down. I have a few ideas on why that might be the case (switch to slow interpreted languages, switch to bigger web frameworks, bigger payload) but even that wouldn't explain all of it. Do you have any idea why things are this way?
  - crazy_horse 5y ago
    This is just basic use the right tools for the right job 101. You've got what is basically a static website. You want to serve static files. To do that, you use a fast language and/or servers written in those languages. It's something anyone who has done this for any length of time knows, that HN is impressed by this is confusing to some of us. If you were trying to get as little out of your server as possible you'd serve cached content using this framework in this language. Is this stuff not being learned?
    - Zababa 5y ago
      I thought you meant from 10k to 50 rps doing the same work, not that most of the work could be avoided in the first place. > Is this stuff not being learned? I don't know if it is. I recently finished my studies, and most people had no curiosity at all. As in, they learned a framework early, used it everywhere, and got a job using it. I do remember reading a few times on tutorial that you should put a Nginx as reverse proxy in front of your Django/Flask/Express server to server static files, so I think most people know/do that but I'm not sure. On the other hand, having the wisdom of knowing what can be static in the first place? I don't think that it's something teached. In fact this kind of wisdom can be hard to find outside of reading lots of sources frequently in hope of finding little nuggets like that. I don't think I was ever taught explicitely "You should first try to find out if the work you're trying to do is necessary in the first place". In a way it's encoded in YAGNI, but YAGNI isn't universal, and is usually understood at the code level and not the tooling level.
- Matthias1 5y ago
  I generally agree with your comment. But the point here is not this is cutting edge performance or anything, but rather that people on HN know how to set up this type of website. If you have any tips on how to get ~10k rps (or even a more reasonable improvement) on a £4 a month server, I at least would be very interested in hearing about them.
wpietri 5y ago
An awful lot of professional programmers work in such heavyweight contexts that they don't have a good idea of how fast modern hardware can be. I was talking with an architect at a bank whose team was having trouble getting under a 2-second maximum for page views. They blamed it on having to make TCP requests to other services, and said something like "at a couple hundred milliseconds per request, it adds up quickly!" My head nearly exploded at that. I spun up some quick tests in AWS to show exactly how many requests one could make in 2000 ms. I don't have the numbers handy, but the number is very large. This junky slice of a server handling full page requests in 20 ms is a fine example to counter thinking that's endemic in enterprise spaces.
- dragontamer 5y ago
  I had a discussion with a coworker about something about slow memcpys, that roughly went the same way except... you know, DDR4 RAM has a speed of roughly 40GBps. Also, that "awful" 1MB memcpy is likely all in L3 cache these days. But even if it weren't in cache, we're talking about an operation that takes 50 microseconds (1MB read + 1MB written == 25microseconds + 25 microseconds). Given that modern CPUs have like 16+ MBs of L3 cache (and more), and some mainstream desktop CPUs have 1MB of L2 cache... its very possible that this memcpy is far faster in practice than you can imagine. 1MB is big, its a million bytes. But CPUs are on the scale of billions, so 1MB is actually rather small by modern standards. Its surprisingly difficult to get intuition correct these days...
  - wpietri 5y ago
    For sure. I think keeping one's intuition for systems updated is one of the biggest quests for anybody trying to have a career in tech.
- ppeetteerr 5y ago
  This is a person running a blog and pulling HTML data from a database. Is it that impressive that they are getting 50r/s?
  - 5y ago

How did this make it to the number two spot on HackerNews?

deleted 5y ago

[deleted]

deleted 5y ago

[deleted]

ok_coo 5y ago

IMHO, it's better than a deluge of political posts. I don't mind reading about politics but I come to HN to read about tech. We can go elsewhere to get whatever politics we desire.

dreyfan 5y ago

Broadly speaking people on HN have no clue how to setup a performant httpd/app server and are impressed by abysmal performance/cost metrics like this or the MangaDex post. Everything these days is obscured through multiple layers of SaaS offerings and unnecessary bloat like kubernetes. ~10k rps (it was concurrent connections but close enough) was state of the art in 1999. Now 22 years later ~50 rps is somehow impressive.

watermelon0 5y ago
I would guess this is close to a default Apache + mod_wsgi setup, and this is one of the easiest way of hosting Python web apps, so basically achievable by anyone on HN. I assume (based on 180 req/s for static page) that he is using mpm_prefork, where each Apache child handles a single connection. If he switched to mpm_event, which uses event loop like nginx, ~10k rps should easily be achievable, but I don't think WSGI would work with that.
- mark_mcnally_je 5y ago
  Yeah it's all default apache + mod_wsgi. This is also my first Django setup and I made it over-complicated as a learning exercise. mpm_event is something I have not heard of before, thanks for bringing that to my attention.
reilly3000 5y ago
In my opinion it isn’t so much of a lost art or lamentable accretion of useless abstractions, but an increase in the scope of what web apps do these days. Most of us aren’t working on static sites or simple CMS publishing- those are a solved problem. Instead we’re building mobile banks, diagnostic systems, software tooling, 3D games, and shopping malls. The complexity is inherent in the maturity of the web and it’s many uses, as well as its global scale. Hugs of death are rare these days thanks to better architecture and infrastructure, even though the scale of users has grown 100X. Yes there are wildly unnecessary abstractions that are used for small sites/apps, but I would contend they are artifacts of someone who it’s trying to learn something new, and/or get promoted. I have no problem with the former.
ppeetteerr 5y ago
The author provides no information other than to say it's an Apache + Django setup. That's pretty bare-bones and is part of most tutorials online.
Zababa 5y ago
> ~10k rps (it was concurrent connections but close enough) was state of the art in 1999. Now 22 years later ~50 rps is somehow impressive. I honestly don't understand how that can be true. I'm not suggesting you're lying of course, but when you put it this way it's almost like people are actively trying to slow their programs down. I have a few ideas on why that might be the case (switch to slow interpreted languages, switch to bigger web frameworks, bigger payload) but even that wouldn't explain all of it. Do you have any idea why things are this way?
- crazy_horse 5y ago
  This is just basic use the right tools for the right job 101. You've got what is basically a static website. You want to serve static files. To do that, you use a fast language and/or servers written in those languages. It's something anyone who has done this for any length of time knows, that HN is impressed by this is confusing to some of us. If you were trying to get as little out of your server as possible you'd serve cached content using this framework in this language. Is this stuff not being learned?
  - Zababa 5y ago
    I thought you meant from 10k to 50 rps doing the same work, not that most of the work could be avoided in the first place. > Is this stuff not being learned? I don't know if it is. I recently finished my studies, and most people had no curiosity at all. As in, they learned a framework early, used it everywhere, and got a job using it. I do remember reading a few times on tutorial that you should put a Nginx as reverse proxy in front of your Django/Flask/Express server to server static files, so I think most people know/do that but I'm not sure. On the other hand, having the wisdom of knowing what can be static in the first place? I don't think that it's something teached. In fact this kind of wisdom can be hard to find outside of reading lots of sources frequently in hope of finding little nuggets like that. I don't think I was ever taught explicitely "You should first try to find out if the work you're trying to do is necessary in the first place". In a way it's encoded in YAGNI, but YAGNI isn't universal, and is usually understood at the code level and not the tooling level.
Matthias1 5y ago
I generally agree with your comment. But the point here is not this is cutting edge performance or anything, but rather that people on HN know how to set up this type of website. If you have any tips on how to get ~10k rps (or even a more reasonable improvement) on a £4 a month server, I at least would be very interested in hearing about them.

wpietri 5y ago

An awful lot of professional programmers work in such heavyweight contexts that they don't have a good idea of how fast modern hardware can be. I was talking with an architect at a bank whose team was having trouble getting under a 2-second maximum for page views. They blamed it on having to make TCP requests to other services, and said something like "at a couple hundred milliseconds per request, it adds up quickly!" My head nearly exploded at that. I spun up some quick tests in AWS to show exactly how many requests one could make in 2000 ms. I don't have the numbers handy, but the number is very large. This junky slice of a server handling full page requests in 20 ms is a fine example to counter thinking that's endemic in enterprise spaces.

dragontamer 5y ago
I had a discussion with a coworker about something about slow memcpys, that roughly went the same way except... you know, DDR4 RAM has a speed of roughly 40GBps. Also, that "awful" 1MB memcpy is likely all in L3 cache these days. But even if it weren't in cache, we're talking about an operation that takes 50 microseconds (1MB read + 1MB written == 25microseconds + 25 microseconds). Given that modern CPUs have like 16+ MBs of L3 cache (and more), and some mainstream desktop CPUs have 1MB of L2 cache... its very possible that this memcpy is far faster in practice than you can imagine. 1MB is big, its a million bytes. But CPUs are on the scale of billions, so 1MB is actually rather small by modern standards. Its surprisingly difficult to get intuition correct these days...
- wpietri 5y ago
  For sure. I think keeping one's intuition for systems updated is one of the biggest quests for anybody trying to have a career in tech.
ppeetteerr 5y ago
This is a person running a blog and pulling HTML data from a database. Is it that impressive that they are getting 50r/s?
- 5y ago