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= Download Performance =

The prime performance criteria of a P2P client is the
speed at which files are downloaded. This area of Tribler 
research specifically examines the source code to
improve downloading. 

Several other research topics are linked to this 
activity. All the research topics below relate to
the Tribler download core. It is imperative that
these efforts are not hindered.

 * We will conduct
 ''several more years'' of P2P research with Tribler.
 The flexibility of the source code is a prime concern.
 Radical architectural enhancements for the long-term are 
 pursued. Thus it is required that modifications remain easy to make.
 For example, 
 [wiki:FullIncentivisation full incentives for all 8 file sharing activities].
 This creates tension with efficiency,
 as Python is easy to modify, but slower then pure C code.
 In a few months we will even 
 [wiki:Give-To-Get remove the tit-for-tat and unchoke algorithm] when two
 [wiki:BarterCast Tribler peers exchange bytes].
 Instead we will keep accurate accounts of exchanged bytes
 and global [wiki:triblerGUIBandwidthSharing sharing ratios between Tribler peers].
 * HTML-page size scalability. We are scaling the Bittorrent protocol for 
 KBytes sized files, meaning it can be used [wiki:P2PWebhosting for static-page P2P webhosting].
 * Fairness. Replacement of the superseeding
 algorithm with [wiki:SupervisedTeaming something superior].
 * [wiki:CooperativeDownload Donating upload to friends]. The Tribler core is
 the only Bittorrent-compatible client which supports this feature.

"Currently Tribler 4.0 is a Bittorrent client with a
secure foundation and pretty interface. However, the
download speed leaves something to be desired
and needs to be improved. "

== Long-term Objective ==

Objective: Speed testing confirms that Tribler
is now ''the fastest'' or a fast Bittorrent client :-)
With the noted exception of 
[http://digg.com/tech_news/BitTorrent_Bullies_BitTyrant_and_BitThief clients whom are parasitic].

== Project 2 ideas ==

The aim of this project is to create an extensive testing suite for Bittorrent clients. At this point we have created a scripted environment that measures the performance of several bittorrent clients within the same swarm.

The Bittorrent clients that we've been testing are:

 * Bittorent Mainline Client
 * Bittornado
 * Transmission
 * Aria2
 * Azureus
 * Tribler

The environment setup is:
 * 6 PCs each running a different client
 * all clients run in the same swarm but with little interraction
 * a huge swarm
 * a large file (a DVD or HD movie)

We measure:
 * the evolution of the download speed for each particular client
 * download time
 * other aspects based on logging information for each client

In order to achieve important results it is important to test a plethora of situations. Based on the above results we can draw conclusions and find out which facilities end up as the most important ones from a performace evaluator's point of view.

Key performance indicators?
 * peer discovery efficiency
 * piece request management
 * unchoke strategy
 * connection management

Stay tuned for more information.

== Project 1 results ==

 * ''2007-05-04'' [attachment:"Initial Project Planning.pdf" Initial Project Planning]
 * ''2007-05-04'' [attachment:"Measurement Plan.pdf" Measurement Plan]
 * ''2007-05-11'' Added logging abilities to BT clients.
 * ''2007-05-27'' Performance Measuring of Azureus, Tribler and Mainline.
 * ''2007-05-27'' Analysis Download Algorithms

Phase 1 in progress:
 * Designing Measurement Tool (10%) ''(mentioned in Design Phase in [attachment:"Revised Project Planning.pdf" Revised Project Planning])''
 * Implementing Measurement Tool (0%)

== Measurements graph ==

Plot using the collected log files
the following properties in time.

 - Peer discovery (tracker, DHT, PEX)
 - Tryout of peers (cumulative optimistic unchoke)
 - Usefullness of peers (total download bandwidth)

This provides insight in the: 

  - peer discovery aggressiveness (tracker interval)
  - optimistic unchoke strategy
  - relative total P2P performance 

Direction of conclusions :

  - Smartness of each client 
    * Unchoke: random, round robin, etc.
    * Piece picking
      * Endgame 
      * First piece
    * Neighborhood health / peer discovery (DHT, PEX)
    * Azureus extra control messages, comments, DHT, and added value
    * Record and ban client with protocol violations or bad hashes
    * Others ? ?
  - Efficiency ranking of clients
  - Best generic algorithms

Application graphs
 * Tribler [http://bsc.fawo.nl/graphs/tribler.png png] [http://bsc.fawo.nl/graphs/tribler.svg svg] [http://bsc.fawo.nl/graphs/tribler.eps Postscript]
 * Mainline bittorrent [http://bsc.fawo.nl/graphs/mainline.png png] [http://bsc.fawo.nl/graphs/mainline.svg svg] [http://bsc.fawo.nl/graphs/mainline.eps Postscript]
 * Azureus [http://bsc.fawo.nl/graphs/azureus.png png] [http://bsc.fawo.nl/graphs/azureus.svg svg] [http://bsc.fawo.nl/graphs/azureus.eps Postscript]
 * Azureus without DHT [http://bsc.fawo.nl/graphs/azureus_nodht.png png] [http://bsc.fawo.nl/graphs/azureus_nodht.svg svg] [http://bsc.fawo.nl/graphs/azureus_nodht.eps Postscript]

Property graphs
 * Unique unchokes, unchokes and chokes [http://bsc.fawo.nl/graphs/chokes_unchokes_unique_unchokes.png png] [http://bsc.fawo.nl/graphs/chokes_unchokes_unique_unchokes.svg svg] [http://bsc.fawo.nl/graphs/chokes_unchokes_unique_unchokes.eps Postscript]
 * Unique unchokes [http://bsc.fawo.nl/graphs/unique_unchokes.png png] [http://bsc.fawo.nl/graphs/unique_unchokes.svg svg] [http://bsc.fawo.nl/graphs/unique_unchokes.eps Postscript]
 * Unchokes [http://bsc.fawo.nl/graphs/unchokes.png png] [http://bsc.fawo.nl/graphs/unchokes.svg svg] [http://bsc.fawo.nl/graphs/unchokes.eps Postscript]
 * Chokes [http://bsc.fawo.nl/graphs/chokes.png png] [http://bsc.fawo.nl/graphs/chokes.svg svg] [http://bsc.fawo.nl/graphs/chokes.eps Postscript]
 * Download progress [http://bsc.fawo.nl/graphs/progress.png png] [http://bsc.fawo.nl/graphs/progress.svg svg] [http://bsc.fawo.nl/graphs/progress.eps Postscript]
 * Peers found via the tracker, buddycast or DHT [http://bsc.fawo.nl/graphs/peers_trackerpeers_dhtpeers.png png] [http://bsc.fawo.nl/graphs/peers_trackerpeers_dhtpeers.svg svg] [http://bsc.fawo.nl/graphs/peers_trackerpeers_dhtpeers.eps Postscript]
 * Total peers found [http://bsc.fawo.nl/graphs/peers.png png] [http://bsc.fawo.nl/graphs/peers.svg svg] [http://bsc.fawo.nl/graphs/peers.eps Postscript]
 * Peers found via Buddycast/DHT [http://bsc.fawo.nl/graphs/dhtpeers.png png] [http://bsc.fawo.nl/graphs/dhtpeers.svg svg] [http://bsc.fawo.nl/graphs/dhtpeers.eps Postscript]
 * Peers found via a tracker [http://bsc.fawo.nl/graphs/trackerpeers.png png] [http://bsc.fawo.nl/graphs/trackerpeers.svg svg] [http://bsc.fawo.nl/graphs/trackerpeers.eps Postscript]
'''x-axis in seconds'''