[chord] Trace to the lookup process

[Emil Sit]

On Wed, 03 January 2007 at 10:11 (+0900), Hai Dao Le wrote:
> Please let me know how to trace to the lookup process (in recursive
> mode). I guess when a node wants to do a lookup, it first uses
> recroute<T>::dorecroute. If the key is not found, the node then forwards
> to another by recroute<T>::dorecroute_sendroute. Based on that guess, I
> put a code to show the trace but I don't have the expected results. (it
> doesn't show all of the transit nodes as listed in the final result).

Can you be a bit more specific about what you want to see?

If you just want to print out the path after every lookup,
as seen on the node that started the lookup, you can just modify
vnode_impl::find_successor_cb to print out the search_path.

If you want to track the query as it proceeds, each request will
naturally be on a different vnode/lsd/physical-machine and you'll need
to coalesce the logs yourself.  Each recursive routing request has
a unique id that you can use to track a single request.  However,
the requesting machine does not see anything until the lookup
is complete.

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