ubuntu-appstore-developers team mailing list archive

[Rodney Dawes <rodney.dawes@xxxxxxxxxxxxx>]

On Mon, 2014-04-21 at 20:09 -0300, Alejandro J. Cura wrote:
> When using the Apps scope, there's a noticeable delay when loading
> icons of search results and screenshots of previews.

Is the dash re-using the same session to download all the icons? My
network connection is very fast, but it's still a little slow to
download these icons, even on my workstation connected via ethernet to
the network. A very large part of the time is spent, purely in the
connection phase of talking to the server. So I'm seeing two things we
could do, independent of image size, and without even implementing local
caching to disk, that would provide a very useful performance
improvement.

1) Re-use of the connection session to avoid DoSing the server with lots
of requests, and to minimize time in "connecting" phase of the
transaction.

2) Optimize SSL/TLS handshake performance on the server. As all these
requests are happening over HTTPS, the handshake can slow things down,
especially when we're spamming the server with so many independent
connection requests.

I'm seeing in my browser that after about 5 connections, the period
spent in "connecting" to the server (prior to any actual content
transfer of the icon), seems to continually get larger with each
additional request. So it seems like maybe 3 threads in the dash, each
with their own connection to the server, might be optimal, along with
any optimization we can do on the server, to make the HTTPS transaction
as fast as possible.