CoDeeN is a
proxy server
In computer networking, a proxy server is a server application that acts as an intermediary between a client requesting a resource and the server providing that resource.
Instead of connecting directly to a server that can fulfill a request ...
system created at
Princeton University
Princeton University is a private university, private research university in Princeton, New Jersey. Founded in 1746 in Elizabeth, New Jersey, Elizabeth as the College of New Jersey, Princeton is the List of Colonial Colleges, fourth-oldest ins ...
in 2003 and deployed for general use on
PlanetLab
PlanetLab was a group of computers available as a testbed for computer networking and distributed systems research. It was established in 2002 by Prof. Larry L. Peterson and Prof. David Culler, and as of June 2010, it was composed of 1090 nodes at ...
.
It operates as per the following:
# Users set their internet caches to a nearby high bandwidth proxy that participates in the system.
# Requests to that proxy are then forwarded to an appropriate member of the system that is in charge of the file (should be caching it) and that has sent recent updates showing that it is still alive. The file is forwarded to the proxy and thence to the client.
What this means for normal users is that if they use this and a server is slow, however the content is cached on the system, then (after the first upload) requests to that file will be fast. It also means that the request will not be satisfied by the original server, equivalent to free bandwidth.
For rare files this system could be slightly slower than downloading the file itself. The system's speed is also subject to the constraint of number of participating proxies.
For the case of large files requested by many peers, it uses a kind of 'multi-cast stream' from one peer to the others, which then distribute out to their respective proxies.
CoBlitz, a CDN technology firm (2006–2009), was a take-off of this, in that files are not saved in the
web cache
A Web cache (or HTTP cache) is a system for optimizing the World Wide Web. It is implemented both client-side and server-side. The caching of multimedias and other files can result in less overall delay when browsing the Web.
Parts of the syste ...
of a single member of the proxy-system, but are instead saved piece-wise across several members, and 'gathered up' when they are requested. This allows for more sharing of disk space among proxies, and for higher fault tolerance. To access this system, URLs were prefixed with http://coblitz.codeen.org/.
CoBlitz - Scalable Large File Transfer via HTTP
/ref> Verivue Inc. acquired CoBlitz in October 2010.
References
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External links
CoDeeN
Servers (computing)
Distributed data storage