[clug] browser connection question

David Deaves David.Deaves at dd.id.au
Mon Aug 17 00:49:15 UTC 2015

> First, I apologise for interrupting the less technical discussions going on...
> I start firefox and have nothing open. I am observing the activity on my privoxy log.
> I connect to DuckDuckGo and see that connection in the log.
> Without any query I close the window, then even clear cookies and the cache.
> About 3 minutes later I see a connection
> 	"CONNECT duckduckgo.com:443 HTTP/1.1" 200 257620
> The log shows activity without delay and the messages are timestamped anyway.
> What is causing this? I expected the closed tab to be done with this site.

Your browser is being helpful.  Setting up a SSL connection is costly, and 
HTTP/1.1 allows multiple requests over one connection.  So when you first 
connected to duckduckgo it opened the SSL connection, but rather than close it 
immediately only to have to open it again later, it keeps it open for future 
use.  After a period of no use it prunes the no longer required connection.
The same is true of regular TCP connections, they are not as costly as SSL, 
but caching connections is still of value.

Dave !

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