

Ask HN: How many users per server? - almosnow

I understand that there are a lot of variables involved, like:<p>- The service you provide and what your users do
- Your hardware<p>But still it would be interesting to discuss your personal experience with this.<p>For example, I&#x27;m currently developing a kind-of online CMS service. Atm I&#x27;m able to support around 250-300 concurrent users using a modest dual-core server (which performs similar to an Amazon EC2 &#x27;core&#x27;), horizontal scale is almost linear. My current goal is to achieve a rate of 1000 concurrent users on a cheap EC2 instance.<p>As another example, &#x27;somewhere&#x27; I&#x27;ve read that Facebook receives around 100 million of concurrent users. &#x27;Somewhere else&#x27; I-ve read that thay are using around 200,000 servers. So you could think that the efficiency they&#x27;ve achieved is around 500 users per server.
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notduncansmith
Obviously this depends a lot on your stack: Node.js is going to be your best
bet though. Sinatra + Unicorn can drive some pretty nice reqs/second, but if
what you need is actual "concurrency" as opposed to just reqs/second
performance, go Node. Express benchmarks that I ran a few months ago were
showing ~7k requests per second, and I've heard claims of well over 10k.

Depending on your scale, your DB could be another potential bottleneck. Heroku
provides hosted PostgreSQL DB's as a standalone service, and their performance
has served me well in the past; could be worth looking into for you. Also, of
course there's the Mongo in the room: I've heard mixed reviews, and I've never
employed it in production myself so I have no wisdom to impart regarding it.
Just be aware of your options :)

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byoung2
What is the bottleneck you're hitting at 300 concurrent users? Is everything
hosted on a single box? You might see better performance if you had a separate
database and app server if CPU or disk I/O is the bottleneck.

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AznHisoka
1000 concurrent users? Are you prematurely optimizing? Very very very few
sites get that many concurrent users. I own a site that gets 1500 visitors a
day, and usually there's 12-15 concurrent users.

