How to get subscriber info via OPCUA Server

[sangjiexun]

Dear developer, how can I get the subscriber (OPCUA Client) information from OPCUA Server, such as remote device's ip ,address and computer-name, etc.

[kevinherron]

If you're using the server SDK then the Session object has a getClientAddress method on it: https://github.com/eclipse/milo/blob/f5799292024a9fb8c9a025e0664c49d67c1110bf/opc-ua-sdk/sdk-server/src/main/java/org/eclipse/milo/opcua/sdk/server/Session.java#L251-L260

[sangjiexun]

If you're using the server SDK then the Session object has a getClientAddress method on it:

https://github.com/eclipse/milo/blob/f5799292024a9fb8c9a025e0664c49d67c1110bf/opc-ua-sdk/sdk-server/src/main/java/org/eclipse/milo/opcua/sdk/server/Session.java#L251-L260

THANKS!!!

[parvit]

@kevinherron Hi, using the getClientAddress method during a onSessionCreated callback returns a null value. How is it possible to detect on the server when a client has activated the connection and get the correct remote address? Thanks

[kevinherron]

It isn't set until the session is activated.

I think SessionListener in the server was meant to be used internally, by the diagnostics implementation. I'm not sure what use it would be to you as an implementor.

[parvit]

The use case for this is to track the connection and disconnection of clients, the behavior of the library here is strange because when the onSessionClosed callback is invoked, the session object does have the address set.

We work around with a scheduled runner on the server to check the list of sessions, but it would have been nicer to have the callbacks report the correct data. Thanks anyway for the support.

[kevinherron]

It's not that strange, a Session that has been closed was probably activated at some point.

Certain information is set or only available when the Session is activated: https://github.com/eclipse/milo/blob/3419235853491ac89f3391bffd337c8200522522/opc-ua-sdk/sdk-server/src/main/java/org/eclipse/milo/opcua/sdk/server/SessionManager.java#L539-L542

[kevinherron]

That said, I think that the address could be set earlier, however whatever you're trying to do tracking Sessions/Clients might be faulty, because you are probably only interested in activated Sessions, and there is no callback for that.