Multiple concert_clients subscribing to the same topic, limitations?

[samiamlabs]

Hi,

Was making a simple RViz integration for moving multiple robots with navigations stacks from the "concert" side today.

https://www.youtube.com/watch?v=6HC5ZyNKX0Q

I noticed some seeming limitations in subscribing nodes on different masters during this. I published robot poses (with master name/URI and current pose) to /applications/robot_pose on all clients. One node on the concert side listened to the same topic from all clients. That worked fine so i tried a similar thing the other way around for navigation goals.

I published a single topic /concert/move_base_multi (name and pose) and had one node per client listen to this topic. It appeared like only one node at a time could receive on the topic and which node that was changed over time. I solved the problem by publishing on different topics for each client (/concert/master_name/move_base_multi).

Was just wondering if this is a known limitation of the current rocon_multimaster implementation or if something is wrong on my end.

[stonier]

It should work, unless #127 is getting in the way somehow.

How are you making the connections? i.e. are you flipping the concert aggregated /concert/move_base_multi publisher to each client or flipping a subscriber from each client to the concert, or doing some form of advertising?

[samiamlabs]

Hmm, I don't have any problems with subscribing to multiple masters. Only publishing to multiple subscribers. But I it is possible #127 could still be relevant.

I am using the standard flipping rules in the clients.
https://github.com/samiamlabs/dyno/blob/master/dyno_bringup/launch/concert_client.launch
https://github.com/samiamlabs/dyno/blob/master/dyno_unity/launch/concert.launch
(not sure if the conductor is doing anything useful here...)
So the clients flip the move_base_multi subscribers to the concert. Should I be flipping the publisher on the concert instaid?

Client gateway_info

(with firewall to prevent re-flipping, which seems to work but looks messy)

Concert gateway_info

Have tested up to 4 simulated clients, and it works fine if I use separate topics to send the move base (PoseStamped) messages. If I use a shared topic it only works sometimes. If I keep re-sending messages to the shared topic, all robots they eventually receive them and start moving, but it is very unreliable.