trafficserver-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Leif Hedstrom <>
Subject Re: Precedent for single-use URLs?
Date Wed, 31 Oct 2012 20:35:03 GMT
On 10/31/12 9:45 AM, John Allspaw wrote:
> Hey all -
> Is there anyone doing logic in ATS to support single-use URLs?
> Example: I have an mp3. I want exactly one person (i.e. client 
> download) to get at it, and no more. If the download doesn't complete, 
> I'm willing to risk that, no more than one download.
> Has anyone approached this problem within ATS, or always just handled 
> the logic in the origin server? Presumably the object in cache has a 
> reference count associated with it that we can check if >1 than deny?

But this would always be a cache miss then ? Or is the idea that the 
same user can fetch it multiple times ? If it's the former, why not 
always go to origin, and make it non cacheable? If the object is the 
same, but unique URLs for each user, I'd take a slightly different approach:

1) Generate cryptographically signed URLs, personalized, such that it's 
only valid from one client IP (or user cookie or whatever).

2) Validate the URL, if not valid for this particular user + URL combo, 
deny the request

3) Extract the "content" portion of the URL, and use that as the cache key.

The cache doesn't keep any "ref count" on disk (you knew that ;), it 
does have an LRU for the in memory cache. An object that only gets one 
hit, but is cacheable, would get written to disk, but would not be in 
RAM cache.


-- Leif

View raw message