commit f9e4549b7fa80c8d3f459b9dbc960673fca18270 Author: juga0 juga@riseup.net Date: Thu Feb 18 12:34:23 2021 +0000

fix: doc: Update differences Torflow/sbws

Closes #40056 --- docs/source/differences.rst | 59 ++++++++++++++++++++++++++++----------------- 1 file changed, 37 insertions(+), 22 deletions(-)

diff --git a/docs/source/differences.rst b/docs/source/differences.rst index 6f904e5..cf5e636 100644 --- a/docs/source/differences.rst +++ b/docs/source/differences.rst @@ -1,36 +1,51 @@ .. _differences:

-Differences between Torflow aggregation and sbws scaling (May 2020) -------------------------------------------------------------------- +Differences between Torflow and sbws +==================================== + +(Last updated 2020-02-18) + +Aggregating measurements and scaling +------------------------------------ + +Filtering +~~~~~~~~~

Torflow does not exclude relays because of having "few" measurements or "close" -to each other for that relay. +to each other for that relay, like sbws does :ref:`filtering-measurements`. + +However this is currently disabled in sbws. + +Network stream and filtered bandwidth +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Torflow calculates the network stream and filtered averages by type of relay +:ref:`stream-and-filtered-bandwidth-for-all-relays`, while sbws is not taking +into account the type of relay :ref:`scaling-the-bandwidth-measurements`.

-If there are not new measurements for a relay, Torflow uses the previous -calculated bandwidth, instead of the new value:: +Values from the previous Bandwidth File +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

- # If there is a new sample, let's use it for all but guards - if n.measured_at > prev_votes.vote_map[n.idhex].measured_at: +sbws is not reading the previous Bandwidth File, but scaling all the values +with the raw measurements.

- [snip] +Instead, Torflow uses the previous Bandwidth File values in some cases:

- else: - # Reset values. Don't vote/sample this measurement round. - n.revert_to_vote(prev_votes.vote_map[n.idhex]) +- When a relay measurement is older than the one in the previous + Bandwidth File, it uses all the values from the previous Bandwidth File. + (how is possible that the Bandwidth File would have a newer measurements?)::

-The oldest measurements Toflow seems to take are from 4 weeks ago, while sbws -oldest measurements are 5 days old:: + self.new_bw = prev_vote.bw * 1000

- GUARD_SAMPLE_RATE = 2*7*24*60*60 # 2wks +Bandwidth File KeyValues +~~~~~~~~~~~~~~~~~~~~~~~~

- [snip] +sbws does not calculate nor write to the Bandwidth file the ``pid`` variables +and KeyValues that are used in Torflow. Example of Torflow KeyValues not in sbws::

- MAX_AGE = 2*GUARD_SAMPLE_RATE + measured_at=1613547098 updated_at=1613547098 pid_error=11.275680184 pid_error_sum=11.275680184 pid_bw=23255048 pid_delta=11.0140582849 circ_fail=0.0

- [snip] +sbws does not have ``measured_at`` and ``updated_at`` either.

- # old measurements are probably - # better than no measurements. We may not - # measure hibernating routers for days. - # This filter is just to remove REALLY old files - if time.time() - timestamp > MAX_AGE: +Currently the scaled bandwidth in Torflow does not depend on those extra values +and they seem to be just informative.