Load Balancing

[Juliusz Chroboczek]

> - privoxy will use new streams on the same circuit for each of the images
> - polipo will generally pipeline everything over the same stream

Not quite.  Polipo will try to use up to n simultaneous connections to
a given server, where n is

  - 2 for a server that can do pipelining;
  - 4 for a server that can do persistent requests but not pipelining;
  - 8 for a server that cannot do persistent requests.

These magic constants are configurable.

Ideally, Polipo should choose the number of simultaneous connections
depending on an estimate of average queue length, but I haven't
thought about it seriously yet.

> I believe this results in a perceptible performance improvement for general 
> browsing.

I think so too, but some people disagree.  Since I don't want to get
into this discussion again, I refer you to the following friendly flamewar.
(Note that while the tone was not always as polite as it should have
been, Fabian and I live in good friendship and mutual respect.)

Me:
  http://archives.seul.org/or/talk/Apr-2007/msg00056.html

Fabian Keil:
  http://archives.seul.org/or/talk/Apr-2007/msg00063.html

Me:
  http://archives.seul.org/or/talk/Apr-2007/msg00066.html

Me clarifying:
  http://archives.seul.org/or/talk/Apr-2007/msg00069.html

You may also find this paper interesting:

  http://www.w3.org/Protocols/HTTP/Performance/Pipeline.html

                                        Juliusz