Re: conneg considered harmful

Hello folks, been a long time!

A very interesting and educational discussion indeed.

Previously I have pushed quite heavily the support of server-driven conneg,
which is something we enable quite easily in ASP.NET Web API though without
redirects.

It's possible to return a redirect, but that requires the user to do the
heavy lifting.

Can someone elaborate a bit more on the harms of not doing the redirect. I
read through the different threads, but having a concise summary would be
valuable.

A different question this brings up is the concern of costs associated with
doing this in particular for a cloud-hosted deployment where each request
costs money / compute hours.


   - Does adding in this redirect mean there's any significant cost
   increase? If you are talking about secure or data that is dynamically
   generated then a cache may not necessarily help offset that.
   - Does the benefit outweight the cost in these cases?

I am curious what folks on the list are doing with regards to APIs deployed
in the cloud.

Thanks!
Glenn






On Sat, Feb 16, 2013 at 2:01 AM, Alan Dean <[email protected]> wrote:

> **
>
>
> To be clear what Roy actually said was "In general, I avoid content
> negotiation *without redirects* like the plague because of its effect on
> caching." *(my emphasis)*
>
> Regards,
> Alan Dean
>
>
> On Sat, Feb 16, 2013 at 6:01 AM, Peter Williams <[email protected]>wrote:
>
>> Most of those don't talk about why using content negotiation is bad in
>> general.  Instead they talk about how truly different resources should have
>> their own uris even if they are variants of one another (eg articles about
>> the same subject written in different human languages). That seems very
>> reasonable.  However, those arguments don't apply to situations where
>> multiple, truly mechanically translatable, representations of a single
>> resource exist.
>>
>> One of those mention that conneg has a negative effect on caching. Is
>> being harder to cache the only ill effect of sever driven conneg?
>>
>> Peter
>> Barelyenough.org
>> On Feb 15, 2013 3:31 PM, "Alan Dean" <[email protected]> wrote:
>>
>>> Perhaps it is worth referencing some other other Fielding quotes on the
>>> subject:
>>>
>>> https://delicious.com/alan.dean/Roy.Fielding+conneg
>>>
>>> Regards,
>>> Alan Dean
>>>
>>>
>>> On Fri, Feb 15, 2013 at 8:21 PM, Peter Williams <[email protected]>wrote:
>>>
>>>> **
>>>>
>>>>
>>>> Eric,
>>>>
>>>> That is an interesting quote. I have occasionally heard
>>>> unsubstantiated claims regarding the badness of accept header based
>>>> content negotiation. It is interesting that Roy perceives it as
>>>> "revolting".
>>>>
>>>> Personally, i rather like it but perhaps i am missing something
>>>> important. I'd definitely like to hear someone (or multiple someones)
>>>> actually articulate what they perceive as problematic about it. So far
>>>> i don't recall ever reading a discussion of the downsides that got
>>>> beyond "i don't like it" or "it is hard for me to implement" (neither
>>>> of which resonate with me).
>>>>
>>>>
>>>> On Wed, Feb 13, 2013 at 9:04 AM, Eric J. Bowman [email protected]>
>>>> wrote:
>>>> > Mark Baker wrote:
>>>> >>
>>>> >> Besides, client driven uses hypermedia so is way more RESTful.
>>>>
>>>> Mark, can you explain a bit more why you think this? It is not clear
>>>> to me why avoiding this particular part of http's uniform interface
>>>> would make a client more RESTful.
>>>>
>>>> Peter
>>>> barelyenough.org
>>>>
>>>>
>>>
>  
>