How do I DOS-proof my cache

[David Young <david@xxxxxxxxxxxxxxx>]

Hey Squid users :)

We had a problem recently where a user with a misconfigured download  
accelerator was able to bring our proxy to its knees, downloading an  
80MB driver about 100 times in parallel. We temporarily solved the  
problem by stopping the download accelerator, but this makes me aware  
of how vulnerable our proxy is to heavy DOS-type attacks.

I've read a bit about the partial object caching expected in 3.1,  
range_offset, and half-closed clients. Can anybody share some ideas  
for making a squid cache more resilient to this kind of abuse / attack?

Thanks!
- David