Squid vs Varnish: What are the differences?
Squid: A caching proxy for the Web supporting HTTP, HTTPS, FTP, and more. Squid reduces bandwidth and improves response times by caching and reusing frequently-requested web pages. Squid has extensive access controls and makes a great server accelerator. It runs on most available operating systems, including Windows and is licensed under the GNU GPL; Varnish: High-performance HTTP accelerator. Varnish Cache is a web application accelerator also known as a caching HTTP reverse proxy. You install it in front of any server that speaks HTTP and configure it to cache the contents. Varnish Cache is really, really fast. It typically speeds up delivery with a factor of 300 - 1000x, depending on your architecture.
Squid and Varnish can be categorized as "Web Cache" tools.
Squid and Varnish are both open source tools. Varnish with 908 GitHub stars and 216 forks on GitHub appears to be more popular than Squid with 560 GitHub stars and 202 GitHub forks.
What is Squid?
What is Varnish?
Want advice about which of these to choose?Ask the StackShare community!
What are the cons of using Squid?
What are the cons of using Varnish?
What tools integrate with Squid?
What tools integrate with Varnish?
When you visit the site, you talk to a load balancer which chooses a varnish front-end which in turn talks to our web front-ends which used to run nine python processes. Each of these processes are serving the exact same version on any given web front-end.
Varnish sits as a secondary cache layer behind Akamai. Two servers operate in a Primary/Secondary configuration with failover managed by HAProxy. Requests peak at around 10k/s.
Varnish is the http cache proxy we use to achieve maximum performance on high traffic e-commerce.