Opened 8 years ago

Closed 8 years ago

#1644 closed task (implemented)

Calculate request share from descriptor archives rather than believing in what relays say

Reported by: karsten Owned by: Karsten
Priority: Medium Milestone:
Component: Metrics/CollecTor Version:
Severity: Keywords:
Cc: Actual Points:
Parent ID: Points:
Reviewer: Sponsor:

Description

When estimating the number of recurring daily users, we divide the number of locally observed requests by the expected share of requests seen at that directory. The result is the estimated number of total requests in the network. Right now, we're using self-reported request shares for this calculation, but these numbers may be wrong. Only recently in May and June 2010, the directories report very low shares of 1/10 of the usual shares or even 0.0%, which must be wrong. Rather than believing the relays here, we could determine request shares that directories should see from the descriptor archives. The descriptor archives reveal how many directory mirrors there are and what bandwidths they advertise that are used for load balancing by clients. The request share of one of the directories is its bandwidth divided by the bandwidth of all directories.

Child Tickets

Change History (1)

comment:1 Changed 8 years ago by karsten

Resolution: implemented
Status: newclosed

We found a better metric for the fraction of directory requests that a directory mirror should expect to see. For details see the tech report on Privacy-preserving Ways to Estimate the Number of Tor Users. Closing.

Note: See TracTickets for help on using tickets.