[Flex/BlazeDS] Detected duplicate HTTP-based FlexSessions

[wiradikusuma]

Hi, I don't know if it's Spring dm Server problem or not, but I never experienced this problem using plain Tomcat.

I'm developing a Service-shared WAR with Flex in the front-end using BlazeDS. Sometimes, when I hit server from Flex (using RemoteObject), I got this exception:

[2009-02-01 12:48:20.983] server-tomcat-thread-46   System.out I [BlazeDS]FlexSession created with id '1E39E7DF22326887732332C01C2E3982.jvm1' for an Http-based client connection.
[2009-02-01 12:48:20.984] server-tomcat-thread-46   System.out I [BlazeDS]Serializing AMF/HTTP response
[2009-02-01 12:48:20.984] server-tomcat-thread-46   System.out I Version: 3
[2009-02-01 12:48:20.984] server-tomcat-thread-46   System.out I   (Header #0 name=AppendToGatewayUrl, mustUnderstand=true)
[2009-02-01 12:48:20.984] server-tomcat-thread-46   System.out I     ";jsessionid=1E39E7DF22326887732332C01C2E3982.jvm1"
[2009-02-01 12:48:20.985] server-tomcat-thread-46   System.out I   (Message #0 targetURI=/14/onStatus, responseURI=)
[2009-02-01 12:48:20.985] server-tomcat-thread-46   System.out I     (Typed Object #0 'flex.messaging.messages.ErrorMessage')
[2009-02-01 12:48:20.985] server-tomcat-thread-46   System.out I       rootCause = null
[2009-02-01 12:48:20.985] server-tomcat-thread-46   System.out I       destination = "carrierService"
[2009-02-01 12:48:20.985] server-tomcat-thread-46   System.out I       headers = (Object #1)
[2009-02-01 12:48:20.985] server-tomcat-thread-46   System.out I       correlationId = "9F686922-182F-80BE-7EB8-30615C369056"
[2009-02-01 12:48:20.985] server-tomcat-thread-46   System.out I       faultString = "Detected duplicate HTTP-based FlexSessions, generally due to the remote host disabling session cookies. Session cookies must be enabled to manage the client connection correctly."
[2009-02-01 12:48:20.986] server-tomcat-thread-46   System.out I       messageId = "251DB2C0-F80C-2E59-EE84-57EF88CDD8F4"
[2009-02-01 12:48:20.986] server-tomcat-thread-46   System.out I       faultCode = "Server.Processing.DuplicateSessionDetected"
[2009-02-01 12:48:20.986] server-tomcat-thread-46   System.out I       timeToLive = 0.0
[2009-02-01 12:48:20.986] server-tomcat-thread-46   System.out I       extendedData = null
[2009-02-01 12:48:20.986] server-tomcat-thread-46   System.out I       faultDetail = null
[2009-02-01 12:48:20.986] server-tomcat-thread-46   System.out I       clientId = "25132B8E-440F-9526-C683-18AE88355C08"
[2009-02-01 12:48:20.986] server-tomcat-thread-46   System.out I       timestamp = 1.233467300984E12
[2009-02-01 12:48:20.987] server-tomcat-thread-46   System.out I       body = null
[2009-02-01 12:48:20.987] server-tomcat-thread-46   System.out I

The problem appears intermittently, but usually in successive invocation after a long pause (e.g. I'm clicking "Save" button, successfully processed, take a nap, click the button again, exception thrown).

[wiradikusuma]

65 views and nobody have a solution?

I'm still experiencing the problem. In Flex, we usually put initialization method in "creationComplete" event. In my case, I call several remote methods to fill some combo-boxes. The problem is, only the first call succeed, the others will throw that "duplicate FlexSessions" stuff.

I googled and found http://bugs.adobe.com/jira/browse/BLZ-268 (Adobe JIRA), but they said the problem only applies to cluster (which is not in my case).

[lance]

Just ran into this last night too and have been searching high and low for a solution.

In my setup I am running 2 JBoss servers with mod_jk to loadbalance them. One server runs fine and will churn through 5000 requests without a hiccup but the other virtually identical system will die after a few hundred.

The error that is produced is identical to what you are seeing. The problem definitely isn't related to session stickiness because if I turn off my good server and leave only the problematic one the problem still persists. When I turn off the problematic server the good server will run along for a very long time and almost never produces the problem.

Right now I am just testing the setup out using JMeter to produce the load.

Both servers are:
Ubuntu 8.04 server 32-bit
JDK 1.6.0_12
JBoss 4.2.3 (can't use 5.0.1 because of issues with Spring).
Spring Framework 2.5.6
BlazeDS 3.3.0.5126 (using a nightly build to resolve an issue with IE6 and HTTPS)

[Glyn Normington]

Since this issue is not specific to dm Server, I wonder if there might be a more appropriate forum which would increase the chances of getting an answer?