145-newguard-flag.txt 1.2 KB

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  1. Filename: 145-newguard-flag.txt
  2. Title: Separate "suitable as a guard" from "suitable as a new guard"
  3. Version: $Revision$
  4. Last-Modified: $Date$
  5. Author: Nick Mathewson
  6. Created: 1-Jul-2008
  7. Status: Open
  8. Overview
  9. Right now, Tor has one flag that clients use both to tell which
  10. nodes should be kept as guards, and which nodes should be picked
  11. when choosing new guards. This proposal separates this flag into
  12. two.
  13. Motivation
  14. Balancing clients amoung guards is not done well by our current
  15. algorithm. When a new guard appears, it is chosen by clients
  16. looking for a new guard with the same probability as all existing
  17. guards... but new guards are likelier to be under capacity, whereas
  18. old guards are likelier to be under more use.
  19. Implementation
  20. We add a new flag, NewGuard. Clients will change so that when they
  21. are choosing new guards, they only consider nodes with the NewGuard
  22. flag set.
  23. For now, authorities will always set NewGuard if they are setting
  24. the Guard flag. Later, it will be easy to migrate authorities to
  25. set NewGuard for underused guards.
  26. Alternatives
  27. We might instead have authorities list weights with which nodes
  28. should be picked as guards.