[chord] update operation in Chord

[Emil Sit]

Hello,

On Mon, 24 July 2006 at 16:21 (+0200), Corina Ferdean wrote:
> I'm currently developing a Location Service over Chord, where I need to
> change the value associated to a given key. Does the current
> Chord implementation (in C or C++) provides such update(key, new_value)
> operation? I would appreciate a lot your help.

You can use public key blocks (KEYHASH) which require that each
update be signed and associated with a public key.  This is the
approach used the Semantic Free Referencing design
    http://nms.csail.mit.edu/papers/sfr-nsdi04.html

You can also use unauthenticated blocks (NOAUTH).  This
is the technique used by the OverCite system
http://www.overcite.org/

You can use the dhashclient::insert method to do these updates.

Unfortunately, I don't think there is any really good example code
available for these use cases; the projects I've cited above have
not (to my knowledge) released their source code though you can
contact their respective authors and ask.

-- 
Emil Sit / MIT CSAIL PDOS / http://pdos.csail.mit.edu/chord/