[p2p-hackers] Overlay Weaver: An Overlay Construction Toolkit

shudo at computer.org shudo at computer.org
Mon Jan 16 15:21:10 UTC 2006

I'm pleased to announce the initial release of Overlay Weaver.

  Overlay Weaver: An Overlay Construction Toolkit

It supports overlay algorithm designers in addition to application

For application developers, the toolkit provides a common API for
higher-level services such as distributed hashtable (DHT) and
multicast.  Applications relying on the common API depend no specific
transport protocol, database implementation and routing algorithm.

The toolkit provides multiple routing algorithms, Chord, Kademlia,
Pastry and Tapestry. These algorithms could be implemented only in
hundreds lines of code because of routing layer decomposition. Routing
layer under the higher-level services has been decomposed into
multiple components, routing driver, routing algorithm and messaging
service. The decomposition also facilitates implementation of a new
algorithm. A newly implemented algorithm can be tested, evaluated and
compared on emulator, which can host thousands of virtual nodes It
enables large-scale emulation and fair comparison between algorithms.


- Implemented in Java 5.
  (except part of IPv4 multicast router which is in C.)

- Provides multiple routing algorithms, Chord, Kademlia, Pastry and Tapestry.

- Two routing drivers respectively performing iterative and recursive routing
  work with all routing algorithm (except recursive routing with Kademlia).

- Provides a distributed environment emulator. It has demonstrated
  that it can host 4000 (virtual) nodes on a single 32 bit computer
  with 1 GB memory.

- There are multiple implementations of communication layer,
  with UDP, TCP and emulated messaging layer.
  Note that the UDP implementation does UDP hole punching.

- A visualization tool, Messaging Visualizer provided.
  It shows nodes and communications just in time
  and works both on the emulator and a real network.

There are screenshots and a demonstration provided on the web site.
Please take a look.

We have written a paper but now it's in Japanese. I will prepare an
English paper in few months.

We'd appreciate activities utilizing this toolkit such as application
development, algorithm researches, testbed construction and operation.
We'll support them. Please contact us or subscribe a mailing list.


  Kazuyuki Shudo, Ph.D.		shudo at ni.aist.go.jp, http://www.shudo.net/
  Grid Technology Research Center
  National Institute of Advanced Industrial Science and Technology (AIST)

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