Codeen
Encyclopedia
CoDeeN is a proxy server
system created at Princeton University
in 2003 and deployed for general use on PlanetLab
.
It operates as per the following:
What this means for normal users is that if you 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. Especially for non-cacheable content, you may as well go to the origin host. 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 (2006-2009) was a take-off of this, in that files are not saved in the cache
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, url's are prefixed with http://coblitz.codeen.org/.
Proxy server
In computer networks, a proxy server is a server that acts as an intermediary for requests from clients seeking resources from other servers. A client connects to the proxy server, requesting some service, such as a file, connection, web page, or other resource available from a different server...
system created at Princeton University
Princeton University
Princeton University is a private research university located in Princeton, New Jersey, United States. The school is one of the eight universities of the Ivy League, and is one of the nine Colonial Colleges founded before the American Revolution....
in 2003 and deployed for general use on PlanetLab
PlanetLab
PlanetLab is 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 as of June 2010 was composed of 1090 nodes at 507 sites worldwide...
.
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 you 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. Especially for non-cacheable content, you may as well go to the origin host. 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 (2006-2009) was a take-off of this, in that files are not saved in the cache
Cache
In computer engineering, a cache is a component that transparently stores data so that future requests for that data can be served faster. The data that is stored within a cache might be values that have been computed earlier or duplicates of original values that are stored elsewhere...
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, url's are prefixed with http://coblitz.codeen.org/.