Android Question websockets timeout

[wl]

Hi,

I noticed websockets can detected whether the connection was closed.
It *seems* this happens after a timeout period of around 30 seconds after the last messages that was tried being sent ?

So If I send a keep-alive message each 10 minutes and would disconnect immediately after such a keep-alive message, it would take another 10,5 minutes for the Closed method to be called ?

Is this correct ?

Thank you

 

[Erel]

It will probably disconnect sooner (whenever the underlying socket detect the new state).

You can however send a "ping" message every few seconds. Sending a single byte will not have any bad effect on the performance. See the push framework for example: https://www.b4x.com/android/forum/threads/custom-websocket-based-push-framework.40272/#content

 

[LucaMs]

Is there a way to set the websocket timeout?

I'm reading this answer (now, but I'm still searching)


P.S.
http://download.eclipse.org/jetty/9.../WebSocketClient.html#setMaxIdleTimeout-long-

?

 

[Erel]

See this thread: https://www.b4x.com/android/forum/threads/b4j-webapp-connection-timeout-issue.43811/#content

 

[LucaMs]

Thank you, Erel

 

[LucaMs]

I have tried in this way, in the "websocket (B4J) class":

Private Sub WebSocket_Connected (WebSocket1 As WebSocket)
    ws = WebSocket1
    ws.Session.MaxInactiveInterval = 10 ' seconds
End Sub

So, I expect that the event WebSocket_Disconnected would be triggered after 10 seconds of client inactivity but it wasn't, the connection remains active.

That should be the ideal solution. Otherwise, I thought about using a flag in the "websocket (B4J) class" and test it every X period using a timer, but I have to set this flag for each transaction made by the client and this is a bore (and I might forget to set it).


P.S. and I have to search if many timers (one of each connection) degrade server performance.

 

[LucaMs]

I have tried in this way, in the "websocket (B4J) class":

Private Sub WebSocket_Connected (WebSocket1 As WebSocket)
    ws = WebSocket1
    ws.Session.MaxInactiveInterval = 10 ' seconds
End Sub

View attachment 43738
So, I expect that the event WebSocket_Disconnected would be triggered after 10 seconds of client inactivity but it wasn't, the connection remains active.

That should be the ideal solution. Otherwise, I thought about using a flag in the "websocket (B4J) class" and test it every X period using a timer, but I have to set this flag for each transaction made by the client and this is a bore (and I might forget to set it).


P.S. and I have to search if many timers (one of each connection) degrade server performance.

This is because "probably" ( ) I have confused "session" with "connection" ("... the SESSION will be invalidated...").
Indeed, in that my test the session is no longer valid after 10 seconds.

So, I suppose there is not a way, by setting something, to disconnect a websocket automatically after x minutes of inactivity, right? Should I use timers as I wrote in the previous post?

 

[Erel]

Yes, you should use a timer.

 

[LucaMs]

Yes, you should use a timer.

 

[LucaMs]

Probably (very probably ) I'm wrong but...

I don't know how exactly B4J "creates" a websocket class (internally) but this class provides a websocket and two websocket events, WebSocket_Connected and WebSocket_Disconnected, which correspond to Jetty websocket events.

This document says that there is another event available, On Message; if this event was also available in the "B4J Websocket Class", I could set the flag I mentioned in #6 within the routine that handles this event, avoiding the problems I have mentioned there.

This post is "just to say", because, if it is possible, if you can add this event, I will have to wait for the new version of B4J


Thank you anyway for your previous answers, Erel