Opened 3 years ago

Closed 18 months ago

#20605 closed enhancement (fixed)

Reduce the exponential backoff variance

Reported by: teor Owned by:
Priority: Medium Milestone: Tor: unspecified
Component: Core Tor/Tor Version: Tor: 0.2.9.1-alpha
Severity: Normal Keywords: backoff, tor-client download-schedule
Cc: Actual Points:
Parent ID: #20534 Points: 1
Reviewer: Sponsor:

Description

When we increased the exponent to compensate for there being no initial delay on schedules, this also increased the schedule variance.

We could reduce this variance by having a smaller range of multipliers, for example, choosing next delay from [delay*2, delay*3], rather than [1, delay*3].

We could also add a linear minimum delay increase, for example, choosing next delay from [10, delay*3], rather than [1, delay*3].

Follow-up to #20499, #20597, and #20534.

Child Tickets

Change History (7)

comment:1 Changed 3 years ago by nickm

Points: 1

comment:2 Changed 3 years ago by nickm

Type: defectenhancement

batch modify: I think these are "enhancement", though I could be wrong about some.

comment:3 Changed 3 years ago by nickm

Keywords: triaged-out-20160116 added
Milestone: Tor: 0.3.0.x-finalTor: unspecified

comment:4 Changed 3 years ago by nickm

Keywords: triaged-out-20170116 added; triaged-out-20160116 removed

comment:5 Changed 2 years ago by nickm

Keywords: backoff tor-client download-schedule added; triaged-out-20170116 removed

comment:6 Changed 2 years ago by teor

This would be nice, particularly for chutney.
But it's not a high priority, as nothing is broken right now.

comment:7 Changed 18 months ago by teor

Resolution: fixed
Status: newclosed

We already fixed this ticket using decorrelated jitter.

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