Subscriber without any publishers - lots of new sockets

[chadrockey]

Original author: mate.wol...@gmail.com (May 10, 2012 14:44:02)

What steps will reproduce the problem?

1. In org.apache.xmlrpc.webserver.Webserver, run() method: place some output after serverSocket.accept()
2. Start a rosjava-RosCore, and register a subscriber on a non-published topic. (rostopic echo /foo)
3. You should see lots of sockets being created, with increasing port numbers.

What is the expected output? What do you see instead?
This behaviour seems a little radical. I'm not sure whether it's really a bug, however it doesn't seem to be resource-friendly.

What version of the product are you using? On what operating system?
rosjava is running under Windows 7, the rostopic echo call comes from an Ubuntu Oneiric with ROS electric installed.

Original issue: http://code.google.com/p/rosjava/issues/detail?id=111

[chadrockey]

From damonkoh...@google.com on May 10, 2012 14:53:15
Could you clarify step 1? I'm not sure I understand what is creating the sockets?

[chadrockey]

From mate.wol...@gmail.com on May 10, 2012 15:13:29
There is a line "Socket socket = serverSocket.accept()" in the WebServer.run() method. I've got some debug output after this line to see how often the web server has to handle a new connection. This happens quite often in the case mentioned above (about 10 times per sec), raising the question whether it's normal behavior or not.

[chadrockey]

From damonkoh...@google.com on May 10, 2012 15:18:34
I suspect this is something that rostopic is doing. I'll look into it.

[chadrockey]

From mate.wol...@gmail.com on May 10, 2012 15:21:12
Ok, thanks, however: I didn't find this maybe-bug using rostopic, but by using regular self-implemented nodes (mainly rosjava nodes) - I used rostopic echo really just for reproducing this behavior.