Measure how segment size affects upload/download speed. #809

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zooko · 2009-09-24T06:16:06Z

zooko commented

2009-09-24 06:16:06 +00:00

#392 has measurements from Brian showing that reducing segment size from 1 MiB to 128 KiB reduced upload/download speed drastically on a high-speed LAN. See if this is still true. Maybe make a little graph of upload/download speed at different segments sizes. There is a script being run by the buildbot to measure upload/download speed, which you could use:

http://allmydata.org/buildbot/builders/speed-colo

#392 has measurements from Brian showing that reducing segment size from 1 MiB to 128 KiB reduced upload/download speed drastically on a high-speed LAN. See if this is still true. Maybe make a little graph of upload/download speed at different segments sizes. There is a script being run by the buildbot to measure upload/download speed, which you could use: <http://allmydata.org/buildbot/builders/speed-colo>

zooko added the

labels 2009-09-24 06:16:06 +00:00

zooko added this to the undecided milestone 2009-09-24 06:16:06 +00:00

zooko commented

2009-12-04 18:48:59 +00:00

If you love this ticket, you might also like #398 (allow users to disable use of helper: direct uploads might be faster) and #320 (add streaming (on-line) upload to HTTP interface).

zooko modified the milestone from undecided to 1.7.0

2010-02-27 06:41:46 +00:00

warner was assigned by zooko

2010-02-27 06:45:44 +00:00

zooko commented

2010-05-08 19:44:54 +00:00

If you like this ticket, you might also like the "Brian's New Downloader" bundle of tickets: #800 (improve alacrity by downloading only the part of the Merkle Tree that you need), #798 (improve random-access download to retrieve/decrypt less data), #448 (download: speak to as few servers as possible), #287 (download: tolerate lost or missing servers), and #605 (two-hour delay to connect to a grid from Win32, if there are many storage servers unreachable).

zooko commented

2010-05-08 22:46:18 +00:00

Brian's New Downloader is now planned for v1.8.0.

zooko modified the milestone from 1.7.0 to 1.8.0

2010-05-08 22:46:18 +00:00

zooko commented

2010-05-16 05:28:48 +00:00

By the way Brian has big plans to make some sort of beautiful graphical visualization of network behavior/performance. I can't wait! For one thing, I intend to work on upload code in v1.8 and such visualization would help tremendously.

zooko commented

2010-08-12 20:59:18 +00:00

Kyle Markley did some good work on this but the results are inconclusive:

More measurements and more analysis of Kyle's measurements (especially his packet traces) is warranted!

See also Nathan Eisenberg's benchmarks of 1.7.1 (standard pipeline and segment size settings) with 1.8.0c1 (standard pipeline and segment size settings):

http://tahoe-lafs.org/pipermail/tahoe-dev/2010-August/004930.html

Kyle Markley did some good work on this but the results are inconclusive: * <http://tahoe-lafs.org/pipermail/tahoe-dev/2010-July/004776.html> * <http://tahoe-lafs.org/pipermail/tahoe-dev/2010-July/004781.html> * <http://tahoe-lafs.org/pipermail/tahoe-dev/2010-July/004782.html> * <http://tahoe-lafs.org/pipermail/tahoe-dev/2010-July/004786.html> * <http://tahoe-lafs.org/pipermail/tahoe-dev/2010-August/004853.html> More measurements and more analysis of Kyle's measurements (especially his packet traces) is warranted! See also Nathan Eisenberg's benchmarks of 1.7.1 (standard pipeline and segment size settings) with 1.8.0c1 (standard pipeline and segment size settings): * <http://tahoe-lafs.org/pipermail/tahoe-dev/2010-August/004930.html>

zooko modified the milestone from 1.8.0 to soon

2010-08-12 20:59:31 +00:00

davidsarah commented

2010-09-14 02:03:29 +00:00

If #1110 or #1187 (download pipelining) were implemented, then the download performance should in theory be less sensitive to segment size. The segment size could then be reduced to improve memory usage.

zooko commented

2011-08-18 21:00:28 +00:00

Trunk now has the new visualizer in it, so you could run downloads with different segment sizes and then look at the visualizations to see how the segments sizes changed the network behavior.

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