Commit 14abf1c3 authored by Sebastian Hahn's avatar Sebastian Hahn Committed by Nick Mathewson
Browse files

Don't delay uploading a new desc if bw estimate was 0 

When a tor relay starts up and has no historical information about its
bandwidth capability, it uploads a descriptor with a bw estimate of 0.
It then starts its bw selftest, but has to wait 20 minutes to upload the
next descriptor due to the MAX_BANDWIDTH_CHANGE_FREQ delay. This change
should mean that on average, relays start seeing meaningful traffic a
little quicker, since they will have a higher chance to appear in the
consensus with a nonzero bw.

Patch by Roger, changes file and comment by Sebastian.
parent bce32e0a

changes/bug13000

0 → 100644
+5 −0
Original line number Diff line number Diff line 
  o Minor bugfixes:

    - If our previous bandwidth estimate was 0 bytes, allow publishing a

      new relay descriptor immediately. Fixes bug 13000; bugfix on

      0.1.1.6-alpha.

src/or/router.c

+3 −2
Original line number Diff line number Diff line
@@ -2063,7 +2063,8 @@ mark_my_descriptor_dirty(const char *reason) 
}



/** How frequently will we republish our descriptor because of large (factor

 * of 2) shifts in estimated bandwidth? */

 * of 2) shifts in estimated bandwidth? Note: We don't use this constant

 * if our previous bandwidth estimate was exactly 0. */

#define MAX_BANDWIDTH_CHANGE_FREQ (20*60)



/** Check whether bandwidth has changed a lot since the last time we announced
@@ -2081,7 +2082,7 @@ check_descriptor_bandwidth_changed(time_t now) 
  if ((prev != cur && (!prev || !cur)) ||

      cur > prev*2 ||

      cur < prev/2) {

    if (last_changed+MAX_BANDWIDTH_CHANGE_FREQ < now) {

    if (last_changed+MAX_BANDWIDTH_CHANGE_FREQ < now || !prev) {

      log_info(LD_GENERAL,

               "Measured bandwidth has changed; rebuilding descriptor.");

      mark_my_descriptor_dirty("bandwidth has changed");