RE: ACTION- 541: Jeni to help Dan pull together terminology on Deep Linking

An archive and a cache share some properties, but their purpose is so fundamentally different that it would be incorrect to call an archive a "kind of cache" in a document whose purpose is to be clear about terminology.

They both may contain copies of material that is or was otherwise available at the "true" origin server.

The purpose of a cache is to improve network performance by not re-transferring data over lower bandwidth or latency links.
The purpose of an archive is to  ensure long-term accessibility of web material that otherwise becomes unavailable over time.

Caches can be cleared at any time. Stale cache material becomes less valuable over time. Cached content should follow the same security and access control model as the original content for which it is a cache.

Clearing an archive destroys the value of an archive. Old archived material becomes more valuable over time. Archived information is likely to have different security and access control policies as the original content. In fact, some archives might even hold material in "escrow" and only provide archived content after a delay.

Larry
--
http://larry.masinter.net


-----Original Message-----
From: www-tag-request@w3.org [mailto:www-tag-request@w3.org] On Behalf Of Jeni Tennison
Sent: Thursday, April 07, 2011 12:46 PM
To: Noah Mendelsohn
Cc: www-tag@w3.org List
Subject: Re: ACTION- 541: Jeni to help Dan pull together terminology on Deep Linking

Noah,

On 7 Apr 2011, at 18:32, Noah Mendelsohn wrote:
> On 3/31/2011 1:51 PM, Henry S. Thompson wrote:
>>   *cache*: to store a copy of something hosted elsewhere and
>>   likewise make it available
> 
> I feel like this is missing something along the lines of:
> 
> *cache*: to store a copy of something hosted elsewhere and likewise make it available. Cached copies are typically created to improve performance or availability, and are usually not managed for long-term stability.
> 
> I don't love that, but I feel your original definition misses the point of a cached copy: it's typically an optimization, and crucially, nothing in the system should behave differently if that copy disappears, except for perhaps being slower or less able to respond in the face of network partition.

In the document as it stands, I class archives as a form of cache, and of course there are archives, such as the internet archive or the UK government's web continuity project, in which the cached copies *are* maintained for long-term stability.

Jeni
-- 
Jeni Tennison
http://www.jenitennison.com

Received on Thursday, 7 April 2011 21:16:45 UTC