tor/changes/bug4483-multiple-consensus-downloads

  o Major features (consensus downloads):
    - Schedule multiple in-progress consensus downloads during client
      bootstrap. Use the first one that starts downloading, close the
      rest. This reduces failures when authorities are slow or down.
      With #15775, it reduces failures due to fallback churn.
      Implements #4483 (reduce failures when authorities are down).
      Patch by "teor".
      Implements IPv4 portions of proposal #210 by "mikeperry" and
      "teor".
Prop210: Add schedules for simultaneous client consensus downloads Prop210: Add attempt-based connection schedules Existing tor schedules increment the schedule position on failure, then retry the connection after the scheduled time. To make multiple simultaneous connections, we need to increment the schedule position when making each attempt, then retry a (potentially simultaneous) connection after the scheduled time. (Also change find_dl_schedule_and_len to find_dl_schedule, as it no longer takes or returns len.) Prop210: Add multiple simultaneous consensus downloads for clients Make connections on TestingClientBootstrapConsensus*DownloadSchedule, incrementing the schedule each time the client attempts to connect. Check if the number of downloads is less than TestingClientBootstrapConsensusMaxInProgressTries before trying any more connections. 2015-12-07 07:55:38 +01:00			`o Major features (consensus downloads):`
			`- Schedule multiple in-progress consensus downloads during client`
			`bootstrap. Use the first one that starts downloading, close the`
			`rest. This reduces failures when authorities are slow or down.`
			`With #15775, it reduces failures due to fallback churn.`
			`Implements #4483 (reduce failures when authorities are down).`
			`Patch by "teor".`
			`Implements IPv4 portions of proposal #210 by "mikeperry" and`
			`"teor".`