Hello again, I just found out about a service from the guys who made CoralCDN: OASIS. >From their description: "OASIS (Overlay-based Anycast Service InfraStructure) is a shared locality-aware server selection infrastructure."
It looks pretty complex but it has the advantage of working properly :-) I haven't read all the technial papers, but it might be interesting to put it to the test with pool.ntp.org. http://www.coralcdn.org/oasis/ Here's the announcement: ===== Over the past few months, we've been working on a general anycast system to replace CoralCDN's current DNS redirection functionality. But more than that, we wanted to build a service of which multiple third-party systems could take advantage. Do you run multiple servers, yet are unable to accurately map clients to the nearest, unloaded instance of your service in an easy manner? Could you benefit by estimating the location of clients accessing your service? If so, OASIS is for you! http://www.coralcdn.org/oasis/ OASIS (Overlay Anycast Service InfraStructure) is a shared locality-aware server selection infrastructure. OASIS is organized as an infrastructure overlay, providing high availability and scalability. At a high level, OASIS allows a service to register a list of servers, then answers the query, ``Which server should the client contact?'' We currently support server-selection via DNS redirection, HTTP redirection and queries, and a special RPC interface. Selection is primarily optimized for network locality, but also incorporates liveness and load. OASIS can, for instance, be used by CGI scripts to redirect clients to an appropriate web mirror. It can locate servers for IP anycast proxies, or it can select distributed SMTP servers in large email services. Yet to eliminate on-demand probing when clients make anycast requests, OASIS probes clients in the background. One of OASIS's main contributions is a set of techniques that makes it practical to measure the entire Internet in advance. By leveraging the locality of the IP prefixes, OASIS probes only each prefix, not each client. Additionally, OASIS delegates measurements to the third-party service replicas themselves using it for anycast, and thus leveraging the additional vantage points and resources of these third-party applications. In doing so, it amortizes measurement costs (approximately 2-10 GB/week) across multiple services, resulting in an acceptable per-node cost. While OASIS is still in alpha testing, we wanted to extend the invitation to other distributed servers that might benefit from such anycast functionality to "check it out." We already have a bunch of third-party services using OASIS for a variety of distributed system applications (Chunkcast, Na Kika, OCALA, OpenDHT, OverCite, etc.) We'd like to make this list even longer... http://www.coralcdn.org/oasis/servers/#current A longer technical description and evaluation of OASIS can be found in our upcoming NSDI '06 paper: http://www.coralcdn.org/pubs/ http://www.coralcdn.org/docs/oasis-nsdi06.pdf We welcome people to subscribe to the OASIS mailing list for future announcements and discussion: http://www.coralcdn.org/lists/ Thanks, Mike Freedman CoralCDN/OASIS Project Lead ===== Best, GFK's -- Guillaume Filion, ing. jr Logidac Tech., Beaumont, Québec, Canada - http://logidac.com/ PGP Key and more: http://guillaume.filion.org/ _______________________________________________ timekeepers mailing list [email protected] https://fortytwo.ch/mailman/cgi-bin/listinfo/timekeepers
