Features in Varnish

[Anders Berg]

I have had the time to mock up a featurelist for Varnish. This is not  
the list that we need to get done pretty soon concering the features  
that Varnish v 1.0 should have, but rather a marketing featurelist  
that will be present on the website. It can of cource be used as a  
base for the aforementioned list.

I have tried to make the list as sexy as possible but may have  
forgotten things we feel are good features. Also I might have taken  
on the marketing hat to hard and overstated the features. So feedback  
is required.

Featurelist Varnish:

- Pure HTTP accelerator
Varnish will deliver cached documents received from your backend(s),  
and do this fast

- Very fast
Varnish is buildt for speed, and should out-perform any other HTTP  
accelerator

- Multiprocessor/core support
Buildt with the future in mind, Varnish supports modern hardware  
technology

- 64-bit computing support
While it can run on a 32-bit platform, Varnish was buildt with 64-bit  
computing in mind

- Modern operatingsystem technology
To be able to deliver content as efficient as possible Varnish takes  
in use the latest operatingsystem features like Kqueue/Epoll and  
Sendfile. Varnish is also IPv6 compatible

- Powerful configuration possibilities
Varnish has a powerful configurationlanguage (VCL) which gives you  
endless possibilities and power over your content. You can reference  
another configurationfile if say your backend is acting slow

- Runtime configuration deployment
Changing of configurationfiles are done in runtime, no need to stop/ 
restart your service(s)

- Protection of backend(s)
Varnish is easily configured to not just stand around and see your  
backend(s) die if you are getting flooded with unwanted traffic. Give  
crawlers the content you feel they deserve. If your backend(s) should  
experience planned or unplanned downtime configure Varnish to never  
expire or fetch new content.

- Ease of managment
Your Varnish server(s) can be centrally controlled from a managment  
program for quick deployment of changes to your system. Different  
interfaces are available for those that don't like the commandline.

- Central and flexible logging
Logs are written to shared-memory, so logging is cheap. A centrally  
controlled logger program connects to the servers and collects these  
data so you can easily customize what, and how, you wanna logg to  
either display or file. This is done securely.

- Realtime statistics
As with logging, we provide you with a centrally controlled  
statistics collector to aggregate numbers from each server or present  
them individially. Again this is done in a securely manner.

- Instant purging
No datastructure traversing will accur, Varnish will instantly purge  
your document(s)

- Wildcard purging
Again, no datastructure traversing is done and all documents (even  
millions) matching your wildcard or regexp will intsantly be rendered  
obsolete and not delivered

- Plugable storage backend(s)
We give you memory, file or tar-file (Read-Only) backend out of the  
box, if you wanna store/read from another backend we leave you with  
an API

- Varnish is free!
Distributed under the two-clause BSD license, Varnish is free of  
charge and anybody can download and modify the sourcecode