Fixing QNetworkAccessManager use

[Johan Ouwerkerk]

On Wed, Feb 19, 2020 at 2:09 PM Friedrich W. H. Kossebau
<kossebau at kde.org> wrote:
>
> Personally I am still unsure what the actual issue is. Why are redirects
> needed at all. Why all the address changes all the time?
>

It is part of the HTTP spec for servers to be able to inform clients
that resource /foo/bar has moved to /bar/baz, either temporarily or
permanently.
This can be used to do things like mapping /retrieve/document/by/alias
-> /documents/actual/document-id, or to redirect to different hosts
entirely, or to inform plain text HTTP clients to upgrade to using
HTTPS instead. (HSTS is a spec describing how a server can then ask
the client to subsequently enforce its policy preference for when to
connect over HTTPS.)

The main difference between temporary and permanent redirects is that
clients are allowed to "remember" when a resource moved in the case of
permanent redirects so they can optimise subsequent calls to the moved
resources (bypassing the redirect entirely). But as you can see, the
temporary redirect is something that could be used to do load
balancing: assume /resource is expensive to compute or retrieve, then
put a proxy in front which load balances to the actual pool of servers
using temporary redirects. (Of course you could argue that in such a
case maybe round-robin DNS is a better solution altogether.)

Regards,

- Johan