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From Leif Hedstrom <>
Subject Re: ATS is not abiding the cache-control's max-age in response header.
Date Mon, 09 May 2011 19:02:43 GMT
On 05/09/2011 12:55 PM, Chilappagari, Sairam wrote:
> *
> *
> So do you think org.apache.cxf.jaxrs.impl.ResponseBuilderImpl is 
> setting the headers wrong? Or ATS is not taking this into 
> consideration? I'm kind of new to ATS so forgive my ignorance.

Let me ask Mnot, but I'd say they are wrong :). From the RFC2616 (sec 4.2):

Multiple message-header fields with the same field-name MAY be present 
in a message if and only if the entire field-value for that header field 
is defined as a comma-separated list [i.e., #(values)]. It MUST be 
possible to combine the multiple header fields into one "field-name: 
field-value" pair, without changing the semantics of the message, by 
appending each subsequent field-value to the first, each separated by a 
comma. The order in which header fields with the same field-name are 
received is therefore significant to the interpretation of the combined 
field value, and thus a proxy MUST NOT change the order of these field 
values when a message is forwarded.

> One more question: If I just use max-age as my caching policy and 
> nothing else, which value am I supposed to use for CONFIG 
> proxy.config.http.cache.required_headers? (1 or 2)?

2. Any time you specify either Cache-Control: or Expires: directly from 
the origin, it's safer to set this config to "2" (which is why it's the 
default). If you set it to "1", then content without explicit cache 
control headers MAY be cached as well, based on heuristics on the 
Last-Modified header. IMO, if you control both the cache and proxy, you 
should always be explicit about cache control policies on the origin 
server (it's where it belongs).


-- Leif

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