1.3 BILLION page views per month
It’s all about performance
That means we transfer 55 TB data / month
9 web servers
RAM: 64GB4 sql servers
Organized as 2 clustersStack Overflow
RAM: 1.5 TB • DB size: 2.8 TBStack Exchange, Careers, Meta
RAM: 768 GB • DB size: 3.9 TB2 redis servers
RAM: 256GB
Master
Replica
It’s a unique custom, high performance index of Stack Exchange questions.
3 tag engine servers
RAM: 64GB3 elasticsearch servers
RAM: 196GB • Load balanced2 Haproxy servers
1 live
1 fail over
Web Sockets
Programming
StackAll of these make the pages render in
12.2ms
home page
18.3ms
questions page
Elasticsearch is a trademark of Elasticsearch BV, registered in the U.S. and in other countries.