[tor-bugs] #2794 [Metrics]: Find a good metric for bridge churn

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#2794: Find a good metric for bridge churn
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 Reporter:  karsten  |          Owner:  karsten
     Type:  task     |         Status:  new    
 Priority:  normal   |      Milestone:         
Component:  Metrics  |        Version:         
 Keywords:           |         Parent:         
   Points:           |   Actualpoints:         
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 We are still lacking a good metric for bridge churn, that is, the rate of
 joining and leaving bridges over time.  If this rate is too high, we
 should give out more bridges to bridge users, because otherwise they'll
 soon end up with bridges that left the network.  If the rate is lower than
 expected, we might even give out fewer bridges, and bridge users will
 still be able to use Tor.

 Here's a possible metric for bridge churn:  Of the bridges that are
 running at the beginning of a month, what fraction keeps running
 throughout the month?  And what fraction of bridges keeps running on the
 same IP address that they had at the beginning of the month?

 In the attachment you'll find a graph for January 2011.  The graph shows
 when bridges that were running on January 2 are listed in the bridge
 network status throughout the month with a) any IP address or b) the same
 IP address.  I'm going to commit the code to metrics-tasks and add a link
 here later today.

 Thoughts?

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/2794>
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