On 28 Jun (13:27:03), Michael Rogers wrote:
Hi,
Better late than never I guess :S...
The Briar team is working on a new app that uses Tor hidden services, and we're trying to work out when the server publishing a hidden service should consider the service to be reachable by clients.
We've tried counting HS descriptor uploads via control port events, but we found that when republishing a hidden service that has been published before, the number of descriptor uploads seems to vary.
When republishing a hidden service, is it guaranteed that at least one copy of the descriptor will be uploaded? Or are there circumstances where Tor might decide that enough copies were previously uploaded, and still contain up-to-date information about introduction points etc, so no new copies need to be uploaded?
Descriptor upload can be quite chaotic and unpredictable. Reason is that there are various cases that can make a service regenerate the descriptors and thus republish them.
But, in all these cases, the descriptor will change as in for the "version" but might not change the intro points information for instance. Such case would be that the HSDir hashring changed and the service noticed so it would immediately upload the existing descriptor(s).
Sometimes, 1 introduction points disappears and so a new one is picked up and a re-upload is done.
And on and on, there are really various cases that can change it.
Not sure I'm fully answering the question but if not, let me know.
Cheers! David