Socket exhaustion - a possible lead?

[Harriet Bazley]

On 22 May 2009 as I do recall,
         Simon Smith <simon_smith at zen.co.uk>  wrote:

> I'm still managing to trigger socket exhaustion from time to time - in fact
> I think I'm getting better at it. The current sequence is reasonably
> reproducible, provided you can find a site that will abort downloads on you
> in mid-stream:
> 
> 1 Load SktCounter
> 
> 2 Start downloading some large files. Mp3s or something; enough to tax your
> connection. I used the ISIHAC collection on archive.org.
> 
> 3 Find a few image-heavy pages and load one. I suspect the faster your
> connection the more pages (and the more image-heavy) you'll need.
> 
> 4 Before the image-heavy page has finished loading, close it.
> 
> 5 Load another image-heavy page, or the same one again.
> 
> 6 At this stage, I still generally see SktCounter hovering at around 60-70
> connections. In fact, it either hovers at around 60-80, or it drops to zero;
> with my setup I have never ever seen a positive socket count of less than
> say, 60.

Same here.

> 
> 7 Keep loading pages and then interrupting the page downloads until one of
> the large file downloads disconnects.

This does sound very much like my frequent pattern of usage - and not
infrequent experience of socket exhaustion.


> 
> 8 As soon as the large downloads disconnect (NOT completing, but with bytes
> to download remaining), I'm finding that my free socket count immediately
> drops to 0. So no more internet until I've reset things.
> 
> 
> I suspect a combination of an aborted page load (item 4) and one or more
> disconnects (8) is the core of the problem. The only significance of the
> image-heavy pages, I reckon, is that because they take longer to load it's
> easier to interrupt them reliably at a critical point.

This would also explain why the phenomenon was more frequent with a
slower computer....

I'll see if I can duplicate your tests, but it might be tricky.

Current settings:
Max fetches: 24
Fetches per host: 5
Cached connections: 6

-- 
Harriet Bazley                     ==  Loyaulte me lie ==

What's the point in being grown up if you can't be childish sometimes?