Add rmw count clients, services#334
Add rmw count clients, services#334methylDragon merged 3 commits intoros2:rollingfrom leeminju531:rolling
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Signed-off-by: leeminju531 <dlalswn531@naver.com>
Signed-off-by: leeminju531 <dlalswn531@naver.com>
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| * This function returns the numbers of servers of a given service in the ROS graph, | ||
| * as discovered so far by the given node. |
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Do we actually support multiple servers on single service name? i believe that we can create the services on the same name, but how it works is really dependent on implementation. If this is supported, i would expect that it can also support load balancing.
IMO, multiple service servers on single topic is not officially supported. in that case, I am not sure what this is for.
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The ROS2 design says
DDS currently does not have a ratified or implemented standard for request-response style RPC which could be used to implement the concept of services in ROS. There is currently an RPC specification being considered for ratification in the OMG DDS working group, and several of the DDS vendors have a draft implementation of the RPC API.
I think It's seem like none of the specification in this situation. I don't know if some supports like load balancing will be added in the future, As long as most vendors allow multiple servers on the same name, it seems like a necessary function even now.
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Do we actually support multiple servers on single service name? i believe that we can create the services on the same name, but how it works is really dependent on implementation. If this is supported, i would expect that it can also support load balancing.
It's not supported, but you can still create more than one.
I think that the default behavior is that all servers reply, no load balancing.
I'm not completely sure though, and I'm not sure if something breaks in that case.
Being able to get the number of service servers still seems okay.
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It's not supported, but you can still create more than one.
I think that the default behavior is that all servers reply, no load balancing.
it seems that it depends on implementation, i just checked with Fast-DDS, it sometimes both servers reply, sometimes only one server replies. for doing this, i guess we need to consider more details, like how we can match the service type, how we can choose the server, how to load balance and so on. this could be new feature.
Being able to get the number of service servers still seems okay.
yeah, at least we can create multiple servers on the same service path.
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Posting this in here for reference too: ros2/rmw_implementation#208 |
this PR is for service counts using it's name like topic.
Related to ros2/ros2cli#771
Signed-off-by: leeminju531 dlalswn531@naver.com