image loading hogs connections-per-server, unfair allocation of http.max-connections-per-server between browser windows




Networking: HTTP
15 years ago
13 years ago


(Reporter: Brian Ristuccia, Assigned: Darin Fisher)



Firefox Tracking Flags

(Not tracked)




15 years ago
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040113

When browsing a page from a site many slow-loading inline images, such that the
number of inline images exceeds http.max-connections-per-server, it becomes
impossible to do any browsing on the same site from a different browser window.

Reproducible: Always
Steps to Reproduce:
1. Make a slowcat CGI script to serve moderately large images at 1200 baud
2. Make a HTML page that sources N of those images, where N is a number roughly
twice as big as max-connections-per-server
3. Start loading that page in browser window A
4. Try to load any other page on the same site in browser window B

Actual Results:  
Browser window B stalls for a very long time until less than
max-connections-per-server images remain unloaded in browser window A. Depending
on how large the images are and how slowly they load, a very long time could
pass before browser window B does anything useful. 

Expected Results:  
Browser window B should load while browser window A continues to load. 

There's a few ways to fix this problem. 

Easiest way might be to make a configurable value max connections per page
loading. If max-conections-per-server were fairly high and max connections per
page was a reasonable percentage of it, behavior when loading multiple pages
from the same server would be acceptable. 

This problem is very commonly seen when using the freenet proxy, since multiple
different sites appear to come from the same HTTP server. Any HTTP<->HTTP proxy
which causes multiple sites to appear as the same URL would have the same
problem, such as the HTTPS proxies sometimes used to facilitate access to office
intranet sites with secure authentication.
Assignee: jdunn → darin
Component: Layout: Images → Networking: HTTP
QA Contact: core.layout.images → httpqa

Comment 2

14 years ago
For freenet specifically, a better solution would be to give a list of
"exception" hosts for which max-connections-per-server doesn't count.
Actually for freenet's sake, even one single exception could be "enough".
I'm a bit unwilling putting the max-connections-per-server to 100 like freenet
FAQ suggests: it really would unnecessarily flood other servers.
Moreover 100 slowly-loading images would be much worse on normal websites (of
freenet of course it's better because freenet itself is quite slow).
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Last Resolved: 13 years ago
Resolution: --- → EXPIRED
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