Re: Redirection to Other IP Addresses

[Bin Ni <[e-mail]>]

Hi Felix,

What you described is exactly what my company (you probably already figured
out that I work for a CDN company)
is providing to our customers today. The problems are:
1. In your example, the first host "cdn.com" is the CDN customer's
hostname. They usually can't provide us with a "*.geo.cdn.com" wildcard
cert. Some of them requires EV certificate, which does not even support
wildcard.
2. Cookies are often targeting a specific hostname. We can't ask all our
customer to change the business logic of their web application to make sure
all cookies are targeting the entire domain.

Hope this helps. Any more questions?

Bin

On Thu, Aug 1, 2019 at 9:37 AM W. Felix Handte <[e-mail]> wrote:

> Bin,
>
> I've been following along on this discussion and it's still not clear to
> me why 30X doesn't solve this use case. Take for example a request and
> response as follows.
>
>    GET /large_file HTTP/1.1
>    Host: cdn.com
>
> To which the server responds with
>
>    HTTP/1.1 307
>    Location: https://singapore.geo.cdn.com/large_file
>
> Or even
>
>    HTTP/1.1 307
>    Location: https://123_45_67_89.ip.cdn.com/large_file
>
> Maybe I'm missing something, but as I understand it, HTTPS and Cookies
> should work with the above (assuming you have wildcard certs for
> *.geo.cdn.com and/or *.ip.cdn.com, and have set your cookies with
> domain=.cdn.com). And it otherwise seems to accomplish exactly your
> intent.
>
> Can you explain in a little more detail why you believe something along
> those lines wouldn't solve your need?
>
> Thanks,
> Felix
>
> On 8/1/19 6:12 AM, Bin Ni wrote:
> > Hi Daniel,
> >
> > At high level, my proposal is in every other way the same as today's 30X
> > redirection.
> > With this in mind, the answer to your questions are:
> > 1. In general, the alternate IP should only be used once for the next
> > single request.
> > But there is nothing to prevent the clients from remembering it, which
> > is OK.
> > Just like there is nothing to prevent a client to disregard the DNS TTL.
> > They do it with their own risk.
> > 2. This proposal is to fix some limitations of the 30X with Location
> header.
> > Not very helpful to make it work together with the Location header.
> > 3. We are not requiring every server and every client to support this
> > proposal.
> > For the ones who find it to be useful, the "extra burden" is a non-issue.
> >
> > Thanks!
> >
> > Bin
> >
> > On Thu, Aug 1, 2019 at 2:18 AM Daniel Stenberg <[e-mail]
> > <mailto:[e-mail]>> wrote:
> >
> >     On Thu, 1 Aug 2019, Bin Ni wrote:
> >
> >      > 2. my proposed behavior:
> >      > Client: Hi Server-1.1.1.1, can you send me the movie XXX?
> >      > Server-1.1.1.1: Sorry, I can't give you the movie, you need to
> >     ask server
> >      > 2.2.2.2 for this movie.
> >      > Client: Hi Server-2.2.2.2, can you send me the movie XXX?
> >      > Server-2.2.2.2: Here is the movie.
> >      > (It then took 0.5 hours to deliver the movie, because
> >     server-2.2.2.2 is
> >      > closer to the client, or less loaded)
> >
> >     If we for a moment play with the idea that we'd do something like
> >     this, then I
> >     think it should be aligned with and work together with Alt-Svc in a
> >     better way
> >     than what is currently proposed...
> >
> >     There's no max-age/TTL. For how long is the user-agent supposed to
> >     consider
> >     the alternative IP addresses as the only ones that the given origin
> >     has?
> >     Forever? Only for the next single connect (attempt)?
> >
> >     Are the alternative IPs supposed to be used for the entire origin or
> >     for that
> >     specific URI only?
> >
> >     A 3xx redirect without a Location: header? Wouldn't it make more
> >     sense and
> >     work more similar to existing 3xx redirects if it also sends a
> >     Location:? Then
> >     existing clients that don't understand 312 might have a higher
> >     chance of at
> >     least doing something sensible.
> >
> >     If a client gets this response and starts downloading huge content
> >     from the
> >     new IP and the client then opens a second connection to the origin
> >     in a second
> >     tab. Which IPs is that supposed to use? The original ones or the
> >     redirected
> >     ones?
> >
> >     Requring user-agent snooping for a server to figure out if the
> >     feature works
> >     or not is a totally broken idea and I think this detail needs to be
> >     worked out
> >     for this idea to be considered for real.
> >
> >     My personal preference is probably to add some sort of "urgency"
> >     thing to
> >     alt-svc instead of this 312 plus several headers, so that a client
> >     can be told
> >     that it should switch sooner rather than later.
> >
> >     --
> >
> >        / daniel.haxx.se <http://daniel.haxx.se>
> >
> >
> >
> > --
> >
> > Bin Ni
> > VP of Engineering
> >
> > Quantil
> >
> > Connecting users with content...it's that simple.
> >
> > Office: [phone] <tel:(888)%20847-9851>
> >
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>
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> >
>


-- 

Bin Ni
VP of Engineering
[image: Quantil]

Connecting users with content...it's that simple.

Office: [phone] <(888)%20847-9851>

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If the reader of this message is not an intended recipient, you are hereby
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strictly prohibited. If you have received this communication in error,
please reply to the sender and destroy all copies of the message. To
contact us directly, send to QUANTIL, INC. at 1919 S Bascom Ave #600,
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or visit our website at www.quantil.com. <https://www.quantil.com/>