[Vaadin7 Push] AssertionError : disconnect(AtmospherePushConnection.java:20

Michele2 · September 2, 2013, 1:18pm

Hi all,

I’m getting a strange error and i can’t figure it out.
I have a simple test case (attached below) using Vaadin 7.1.3 and Apache Tomcat 7.0.42 (I’ve also tryed jetty 8)

Here’s the stack trace:

set 02, 2013 3:03:00 PM org.atmosphere.websocket.DefaultWebSocketProcessor dispatch
WARNING: Failed invoking AtmosphereFramework.doCometSupport()
java.lang.AssertionError
	at com.vaadin.server.communication.AtmospherePushConnection.disconnect(AtmospherePushConnection.java:204)
	at com.vaadin.ui.UI.setPushConnection(UI.java:1399)
	at com.vaadin.server.communication.PushHandler$1.run(PushHandler.java:119)
	at com.vaadin.server.communication.PushHandler.callWithUi(PushHandler.java:289)
	at com.vaadin.server.communication.PushHandler.onRequest(PushHandler.java:306)
	at org.atmosphere.cpr.AsynchronousProcessor.action(AsynchronousProcessor.java:259)
	at org.atmosphere.cpr.AsynchronousProcessor.suspended(AsynchronousProcessor.java:166)
	at org.atmosphere.container.TomcatWebSocketUtil.doService(TomcatWebSocketUtil.java:137)
	at org.atmosphere.container.Tomcat7AsyncSupportWithWebSocket.service(Tomcat7AsyncSupportWithWebSocket.java:59)
	at org.atmosphere.cpr.AtmosphereFramework.doCometSupport(AtmosphereFramework.java:1448)
	at org.atmosphere.websocket.DefaultWebSocketProcessor.dispatch(DefaultWebSocketProcessor.java:219)
	at org.atmosphere.websocket.DefaultWebSocketProcessor.open(DefaultWebSocketProcessor.java:133)
	at org.atmosphere.container.TomcatWebSocketHandler.onOpen(TomcatWebSocketHandler.java:67)
	at org.apache.catalina.websocket.StreamInbound.onUpgradeComplete(StreamInbound.java:247)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:722)

set 02, 2013 3:03:00 PM org.atmosphere.websocket.protocol.SimpleHttpProtocol onError
WARNING: java.lang.AssertionError Status 500 Message Server Error

How to reproduce:
1- Launche the application
2- Click a button (no matter what) to make a push request
3- Refresh the page (F5)

Like i said before i can’t figure out the problem, and i’m quite surprised not finding others reporting this. To me it seem a sync problem where the Ui still store a reference of an already closed pushConnection.

What could it be?
13159.zip (13.3 KB)

Michele2 · September 2, 2013, 2:04pm

Maybe i’ve found something, as i conjecture before, it’s a race condition:

The problem is that when you hit refresh (F5) there are 2 concurrent process:

The creation of a new WebSocket
The closure of the old one

If the closure is completely handled before the new one, all work smoothly. But if the new connection is handled after the end of the closing, the assertion will triggers:

in fact the connection closure will trigger :

DefaultBroadcaster.removeAtmosphereResource() { //... removed = resources.remove(r); //... }that will silently fail if the connection is already closed
But, the new connection will trigger:

[code]
UI.setPushConnection(PushConnection pushConnection) {
//…
if (this.pushConnection != null) {
this.pushConnection.disconnect();
}

this.pushConnection = pushConnection;
//...

}
[/code]and disconnect will trigger the assertion if already closed.

So: if this is the only problem (there might be more…) a solution would be to check if the connection isConnected() before try to disconnect()

Can someone confirm this?
Should i open a ticket?

ps. is it normal that the connection is periodically closed and reopened, should not a webSocket stay opened ?

Reuben1 · September 12, 2013, 4:32pm

I have a similar problem on Vaadin 7.1.5 and Tomcat 7.
Did you manage to work around this?
To make things worse, I am evaluating JRebel for this environment and this exception is now a blocker (without JRebel it was just a log line)

Thanks

Johannes13 · September 12, 2013, 4:47pm

Hi,

This might have the same root cause as tickets
#12226
and
#12522
. A fix is pending a review.

Reuben1 · October 3, 2013, 1:53pm

I tested again on 7.1.6 and my problem is still there.
This is my stack trace (from 7.1.5):


Oct 02, 2013 3:58:14 PM org.atmosphere.cpr.AtmosphereFramework addAtmosphereHandler
INFO: Installed AtmosphereHandler com.vaadin.server.communication.PushHandler mapped to context-path: /*
Oct 02, 2013 3:58:15 PM org.atmosphere.cpr.DefaultBroadcaster <init>
INFO: /* support Out Of Order Broadcast: false
Oct 02, 2013 3:58:15 PM org.atmosphere.cpr.AtmosphereFramework autoDetectWebSocketHandler
INFO: Auto detecting WebSocketHandler in /WEB-INF/classes/
Oct 02, 2013 3:58:17 PM org.atmosphere.cpr.AtmosphereFramework initWebSocket
INFO: Installed WebSocketProtocol org.atmosphere.websocket.protocol.SimpleHttpProtocol 
Oct 02, 2013 3:58:17 PM org.atmosphere.cpr.AtmosphereFramework autoDetectContainer
INFO: Atmosphere is using async support: org.atmosphere.container.Tomcat7AsyncSupportWithWebSocket running under container: Apache Tomcat/7.0.42
Oct 02, 2013 3:58:17 PM org.atmosphere.cpr.AtmosphereFramework configureAtmosphereInterceptor
INFO: Installed Default AtmosphereInterceptor [Android Interceptor Support, SSE Interceptor Support, JSONP Interceptor Support, Atmosphere JavaScript Protocol, Browser disconnection detection]
. Set org.atmosphere.cpr.AtmosphereInterceptor.disableDefaults in your xml to disable them.
Oct 02, 2013 3:58:17 PM org.atmosphere.cpr.AtmosphereFramework init
WARNING: No BroadcasterCache configured. Broadcasted message between client reconnection will be LOST. It is recommended to configure the org.atmosphere.cache.UUIDBroadcasterCache
Oct 02, 2013 3:58:17 PM org.atmosphere.cpr.AtmosphereFramework init
INFO: Shared ExecutorService supported: true
Oct 02, 2013 3:58:17 PM org.atmosphere.cpr.AtmosphereFramework init
INFO: HttpSession supported: true
Oct 02, 2013 3:58:17 PM org.atmosphere.cpr.AtmosphereFramework init
INFO: Using BroadcasterFactory: org.atmosphere.cpr.DefaultBroadcasterFactory
Oct 02, 2013 3:58:17 PM org.atmosphere.cpr.AtmosphereFramework init
INFO: Using WebSocketProcessor: org.atmosphere.websocket.DefaultWebSocketProcessor
Oct 02, 2013 3:58:17 PM org.atmosphere.cpr.AtmosphereFramework init
INFO: Using Broadcaster: org.atmosphere.cpr.DefaultBroadcaster
Oct 02, 2013 3:58:17 PM org.atmosphere.cpr.AtmosphereFramework init
INFO: Atmosphere Framework 1.0.14.vaadin4 started.
Oct 02, 2013 3:58:17 PM org.atmosphere.cpr.AtmosphereFramework interceptor
INFO: Installed AtmosphereInterceptor  Track Message Size Interceptor using |. 
Oct 02, 2013 3:58:18 PM org.atmosphere.websocket.DefaultWebSocketProcessor dispatch
WARNING: Failed invoking AtmosphereFramework.doCometSupport()
java.lang.NoSuchMethodError: org.json.JSONObject.put(Ljava/lang/String;Ljava/util/Collection;)Lorg/json/JSONObject;
	at com.vaadin.server.VaadinService.createCriticalNotificationJSON(VaadinService.java:1555)
	at com.vaadin.server.communication.PushHandler.callWithUi(PushHandler.java:256)
	at com.vaadin.server.communication.PushHandler.onRequest(PushHandler.java:306)
	at org.atmosphere.cpr.AsynchronousProcessor.action(AsynchronousProcessor.java:259)
	at org.atmosphere.cpr.AsynchronousProcessor.suspended(AsynchronousProcessor.java:166)
	at org.atmosphere.container.TomcatWebSocketUtil.doService(TomcatWebSocketUtil.java:137)
	at org.atmosphere.container.Tomcat7AsyncSupportWithWebSocket.service(Tomcat7AsyncSupportWithWebSocket.java:59)
	at org.atmosphere.cpr.AtmosphereFramework.doCometSupport(AtmosphereFramework.java:1448)
	at org.atmosphere.websocket.DefaultWebSocketProcessor.dispatch(DefaultWebSocketProcessor.java:219)
	at org.atmosphere.websocket.DefaultWebSocketProcessor.open(DefaultWebSocketProcessor.java:133)
	at org.atmosphere.container.TomcatWebSocketHandler.onOpen(TomcatWebSocketHandler.java:67)
	at org.apache.catalina.websocket.StreamInbound.onUpgradeComplete(StreamInbound.java:247)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:724)

Oct 02, 2013 3:58:18 PM org.atmosphere.websocket.protocol.SimpleHttpProtocol onError
WARNING: java.lang.NoSuchMethodError: org.json.JSONObject.put(Ljava/lang/String;Ljava/util/Collection;)Lorg/json/JSONObject; Status 500 Message Server Error
Oct 02, 2013 3:58:18 PM org.atmosphere.websocket.DefaultWebSocketProcessor dispatch
WARNING: Failed invoking AtmosphereFramework.doCometSupport()
java.lang.NoSuchMethodError: org.json.JSONObject.put(Ljava/lang/String;Ljava/util/Collection;)Lorg/json/JSONObject;
	at com.vaadin.server.VaadinService.createCriticalNotificationJSON(VaadinService.java:1555)
	at com.vaadin.server.communication.PushHandler.callWithUi(PushHandler.java:256)
	at com.vaadin.server.communication.PushHandler.onRequest(PushHandler.java:306)
	at org.atmosphere.cpr.AsynchronousProcessor.action(AsynchronousProcessor.java:259)
	at org.atmosphere.cpr.AsynchronousProcessor.suspended(AsynchronousProcessor.java:166)
	at org.atmosphere.container.TomcatWebSocketUtil.doService(TomcatWebSocketUtil.java:137)
	at org.atmosphere.container.Tomcat7AsyncSupportWithWebSocket.service(Tomcat7AsyncSupportWithWebSocket.java:59)
	at org.atmosphere.cpr.AtmosphereFramework.doCometSupport(AtmosphereFramework.java:1448)
	at org.atmosphere.websocket.DefaultWebSocketProcessor.dispatch(DefaultWebSocketProcessor.java:219)
	at org.atmosphere.websocket.DefaultWebSocketProcessor.open(DefaultWebSocketProcessor.java:133)
	at org.atmosphere.container.TomcatWebSocketHandler.onOpen(TomcatWebSocketHandler.java:67)
	at org.apache.catalina.websocket.StreamInbound.onUpgradeComplete(StreamInbound.java:247)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
	at java.lang.Thread.run(Thread.java:724)

Oct 02, 2013 3:58:18 PM org.atmosphere.websocket.protocol.SimpleHttpProtocol onError
WARNING: java.lang.NoSuchMethodError: org.json.JSONObject.put(Ljava/lang/String;Ljava/util/Collection;)Lorg/json/JSONObject; Status 500 Message Server Error
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Johannes13 · October 3, 2013, 2:42pm

Sounds like you have a version of org.json in the classpath that conflicts with Vaadin’s one.

Reuben1 · October 3, 2013, 8:05pm

Good point, thanks. We’ll update our ‘other’ json.