StackExchange Performance Stats
stackexchange.com
stackexchange.com
Also running a traditional monolith style system. One main SQL DB. Another for some logs. Redis. Blob storage. KISS.
We have various miscellany and a dozen+ web apps for public website, internal admin, content editing, monitoring, on-the-fly image resizing, etc. but even the API's serving those live in one web app, and our high traffic data & content service is just one app. Nearly everything in one solution and repo.
Tbf, we've been utilizing chromium more over the past year and I think we're going to have to split that out into its own service.
We do a lot of data-driven image generation and used a couple .Net imaging libraries for that until last year. Since then we've been building new data-driven content solely in HTML/JS and screenshotting through chromium to generate static images (we serve the same content in animated HTML and JPG and used to build each separately).
Stack overflow runs on .net
Stack overflow squeezes lots of performance out of very little hardware or cost
Stack overflow doesn’t do that much
Customers haven’t added feature after feature until it resembles a half dog half cow hybrid
Stack overview developers spend time working out how to scale for their specific use case rather that theoretical use cases
I honestly believe that by sticking to a singular narrow focus stack overflow has achieve magnificent things. It isn’t because of .net it is in spite of it.
Well done stack overflow but unless you can stop the business or the users with extra requests or expanding the product you cannot replicate it.
https://blog.codinghorror.com/introducing-stackoverflow-com/
The only time I've personally seen render times that high is with large, complex databases in bad need of indexes and/or restructuring, and with hybrid cloud stuff, where cloud services are using an on-prem API or database.
It was a large database due to unnecessary complexity and we do have indexes but due to poor design it was hard to gain any significant performance gains from adding indexes.
Digging around a bit, it seems that they do use Fastly for edge CDN: https://nickcraver.com/blog/2017/05/22/https-on-stack-overfl....
Still, it's an impressively lean stack.
A webpagetest from Sydney shows pretty dismal performance: https://www.webpagetest.org/result/200801_FJ_dd5f2a76d77bcaa...
~2 seconds for first contentful paint. That's pretty dismal, IMO, and shows the limitation of their current setup.
Well they cant beat the speed of light. What could they do ?
Honestly, I never wanted to get into C# as much because typically, it also means getting into Windows (from personal experience, companies using C# are heavily invested in Windows, and I love using Linux for everything).
Do companies nowadays develop and deploy C# on Linux boxes?
Edit: Just a reaction to a number of responses, I know C# is now fully open source. That doesn't mean companies using C# develop using Linux and deploy on Linux. C# being open source means very little to me when all deployments are on a proprietary platform.
https://meta.stackexchange.com/a/122854
> The main reason, it was the development stack Jeff, Jarrod and Geoff knew best when they embarked on the mission.
Jeff Atwood comments on linked answer also.
I'm more of a Windows guy for desktop, but always prefer Linux for server. Nowadays dotnet is a first class citizen on Linux and MacOS, through dotnet core.
On performance, there has been a big focus on perf by the dotnet team over the past years - I'd be shocked if Java could beat dotnet on just about any metric. If you know what you're doing you can write allocation-free code, and you even have hardware intrinsics at your disposal - I recently ported a hashing algorithm to C# and got the performance pretty close to parity with native C code (almost memory speed).
C# doesn't get much love on HN, but IMO it's a truely fantastic language.
https://devblogs.microsoft.com/dotnet/performance-improvemen...
Which makes a lot of sense. AWS Windows machines cost ~50% more compared to Linux boxes. I was quite surprised at Windows pricing actually; that made it an easy decision to make given that .Net core has been stable on Linux for a while now.
You can also see just how much it's improving in some areas and the level of detail they're paying to it: https://devblogs.microsoft.com/dotnet/performance-improvemen...
Which year was that? Java apps and the JVM in my opinion and experience are very bloated and have a lot of memory consumption and leaks, which cause frequent and annoying GC slowdowns. I shudder to run large Java apps on company servers like the Atlassian stack(Jira, Confluence etc.) and Tableau Server.
Just this week I built and deployed a new C#. NET core API running on a Microsoft provided Ubuntu docker image and it's now ticking along nicely in production.
I still develop on Windows because Visual Studio is for my money the best development environment available but I almost never write new code to run on Windows, with core at publish time its as simple as a command line flag to target Linux. If you don't want to use Windows for development then other OSes are just as viable for developing on, I developed my personal blog on Linux.
It's a shame that people (perhaps understandably) have this image of C# as a legacy environment when it's a language and environment that is constantly innovating and has been sitting around the top of some server benchmarks for quite a while.
I don't think that was ever the case, (Java VM's always had some clever optimizations in due to being more mature, but if you used C# properly and used its value types effectively, you could beat idiomatic Java hands down, and the Java that ran equally fast was often bastardized C-looking java that didn't use proper types but arrays. Basically High perf java only supports AoS, only SoA, which may or may not be convenient).
For a lot of workloads obviously the difference is minuscule, especially if a database or web server is involved (in this case, both).
Features like AOT compilation, or the fact that SQL Server is really powerful database engine that they already knew - in fact, they knew windows platform very well, and do things like putting some critical paths directly using HTTP.SYS kernel driver webserver (IIS uses it as well, but build extra functionality on top)
Compare it with popular open source web stacks of the time - Python, Ruby, PHP, all with no real compilation support, slow or otherwise problematic (PHP's emulation of CGI environment, for example).
But ultimately - they knew their tools well, and applied that knowledge to very good results :)
No groud up re-architecture, no microservice complexity, no crazy high cloud bills for exotic high power VMs. Just upfront capx for your own big iron and the skill to run it.
In terms of opportunities to add complexity: I'm surprised there is no mention of a data-platform or any model training for ranking, etc.
To reduce components, it might be possible to combine ElasticSearch and MSSQL into just PostgreSQL which has awesome text indices. As MSSQL performs very well and presents a somewhat esoteric SQL dialect this could be an expensive project.
https://nickcraver.com/blog/2016/02/17/stack-overflow-the-ar...
It’s surprisingly less infrastructure then I was imagining.
AFAIK they still keep to two datacenters, and the second one is a backup. All of SO sites run from the same few racks.
I would be happy if Ruby Rails could do it in 3x the rendering time ( i.e slower ) with 2x Resources / Server.