Kbase P39012: Which UDP port does a broker use to communicate with Name Server?
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
15/10/2008 |
|
Status: Verified
GOAL:
Which UDP port does a broker use to communicate with Name Server?
GOAL:
Is there a way to configure a broker to use a different UDP port when communicating with Name Server?
GOAL:
What UDP port are involved in the communication between the broker and the name server?
FACT(s) (Environment):
Progress 9.x
WebSpeed 3.x
OpenEdge 10.0A
FIX:
There is keep-alive mechanism between the broker and the NameServer. The NameServer expects to get a keep-alive message from the broker every so often; otherwise, it will assume that the broker has died. The keepalive mechanism is implemented using UDP sockets on the broker and the server.
The NameServer always listens on the UDP port defined for it in the ubroker.properties file, default is 5162.
When the broker starts, it picks a "random" UDP port, for listening for responses from the NameServer. When it sends the registration message to the nameserver, it sends the message to the nameserver's well-known port. This message contains the port number of the broker's UDP listening port. The NameServer reads this port number from the message, and when the broker requests an acknowledgement, sends the acknowledge message back to the broker on the broker's UDP port.
The port that the broker picks is "random" in the sense that Progress does not control the selection of the port. Progress lets the JVM find an available port when it creates the new UDP socket.