[chord] Query re Nodes Leaving and Successor Lists

[Emil Sit]

On Mon, Jun 28, 2010 at 5:56 PM, Aisling O' Driscoll
<odriscoll.aisling at gmail.com> wrote:
> What happens if 2186 has not realised that its predecessor has failed? So
> 2042 will stabilize with 2186. 2186 will return a predecessor of 2129 and
> 2042 will simply add 2129 as its successor again (after having just removed
> it). This is incorrect and it seems to me that the standard stabilization
> mechanisms won’t work.

Indeed, the Chord implementation tracks information about how fresh
one node's information about another node is.  So when Node 2042 has
more recent information than node 2186 about node 2129, it will ignore
the update from node 2186 as stale and wait.  (We track the time since
last contact, which adds the assumption that everyone has clocks that
run at about the same rate, but aren't necessarily synchronized.)

-- 
Emil Sit / http://www.emilsit.net/