From:  Patrick McManus <>
Date:  08 Aug 2017 21:15:14 Hong Kong Time

Re: [necko] How many speculative connections is enough (or too many?)


in general connection costs are low in bandwidth and low in cpu but high in
latency.. so neither end really minds if we make too many. perhaps the
constant 6 is wrong, but I think any adjustment should be based on data
unless there is a firm problem beig reacted to.

determining h2 does not require http, but it does require tls to be
complete.. this info is cached.

On Mon, Aug 7, 2017 at 10:35 PM, Jason Duell  wrote:

> So right now we'll launch a new speculative TCP connection (up to 6) for
> each call to the speculative connect API:
> (For HTTP/2,  presumably they get merged into one socket once we figure
> out we're doing H/2, but we won't know that till we actually issue an HTTP
> request IIUC).
> 1) Are we happy with this as the default behavior?   I'm not sure we want
> to open this many speculative sockets to the same host.
> 2) In this bug we're talking about possibly calling the speculative API
> multiple times for the same logical channel (once when the user gets close
> to a link with the mouse, once when they click down on it, etc, and
> possibly also in some central location(s) in the parent before we send off
> a URIload notice to the child):
> I'm thinking we should add a "no-dupe" version of speculative connect for
> this behavior (i.e. it wouldn't start a new speculative connection if
> there's one to that origin already).   Any other ideas?
> 3) For the case where they want to call the speculative API in the parent
> when we actually know 100% that we'll be navigating there (i.e the only
> reason for the call is to launch the socket immediately without having to
> wait for the parent to notify the child about the load), would we want to
> do the same thing we do for regular channels (open 2 sockets in staggered
> succession)?
> Jason
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