167-params-in-consensus.txt 1.7 KB

1234567891011121314151617181920212223242526272829303132333435363738394041424344454647
  1. Filename: 167-params-in-consensus.txt
  2. Title: Vote on network parameters in consensus
  3. Author: Roger Dingledine
  4. Created: 18-Aug-2009
  5. Status: Closed
  6. Implemented-In: 0.2.2
  7. 0. History
  8. 1. Overview
  9. Several of our new performance plans involve guessing how to tune
  10. clients and relays, yet we won't be able to learn whether we guessed
  11. the right tuning parameters until many people have upgraded. Instead,
  12. we should have directory authorities vote on the parameters, and teach
  13. Tors to read the currently recommended values out of the consensus.
  14. 2. Design
  15. V3 votes should include a new "params" line after the known-flags
  16. line. It contains key=value pairs, where value is an integer.
  17. Consensus documents that are generated with a sufficiently new consensus
  18. method (7?) then include a params line that includes every key listed
  19. in any vote, and the median value for that key (in case of ties,
  20. we use the median closer to zero).
  21. 2.1. Planned keys.
  22. The first planned parameter is "circwindow=101", which is the initial
  23. circuit packaging window that clients and relays should use. Putting
  24. it in the consensus will let us perform experiments with different
  25. values once enough Tors have upgraded -- see proposal 168.
  26. Later parameters might include a weighting for how much to favor quiet
  27. circuits over loud circuits in our round-robin algorithm; a weighting
  28. for how much to prioritize relays over clients if we use an incentive
  29. scheme like the gold-star design; and what fraction of circuits we
  30. should throw out from proposal 151.
  31. 2.2. What about non-integers?
  32. I'm not sure how we would do median on non-integer values. Further,
  33. I don't have any non-integer values in mind yet. So I say we cross
  34. that bridge when we get to it.