(Illustration by Gaich Muramatsu)
On Sat, Oct 09, 2010 at 05:22:32PM +0530, srimugunthan dhandapani wrote: > the algorithm used to map a file's data to the storage servers). I > couldn't obtain the information about coda's data distribution > algorithm from the coda papers. It will be helpful if somebody can It is discussed in several of the papers, but the most concise description is probably in 'The Evolution of Coda', which for some reason doesn't seem to be listed on the page of Coda papers. http://www.google.com/search?q=the+evolution+of+coda > give some helpful pointers about which files in the source code that i > have to look into for understanding how data distribution is done in > coda. Pointing at the actual source files is actually somewhat hard because it is a somewhat fundamental concept in the design of the client. A high level overview is, files on the server are stored in/associated with logical volumes and when these volumes are created the administrator decides which servers will be used as replicas for that particular volume. When new file data is written to the servers it will be sent to the set of volume replicas that is reachable (the Available Volume Storage Group, or AVSG). When a file is read the attributes and version information is retrieved from all available volume replicas, if any replica is out of data resolution is used to propagate the new data to the stale replica. Once all replicas are considered to be in sync the file contents is retrieved from any one of the replicas, typically the one stored on a server that historically responded quickest to requests. JanReceived on 2010-10-13 00:58:05