Working jmeter javaserver faces jsf - how create an XPath to keep the ViewS

Question

Hi all,
I've searching and I found this http://forums.sun.com/thread.jspa?threadID=664673&messageID=4418665#4418665 ...
I manage to test JSF 1.2 using JMeter but there is a trick, even if you are using the HTTP Proxy:
1) The first HTTP request get a page with a form.
2) The second request perform a JSF action on this form.
Make sure that you are sending the value of javax.faces.ViewState found in the from at the second request, otherwise the View restore may fail.
For this, create a XPath extractor. The XPath query is: //input/@value. Choose a reference name, ViewState per example.
In the second http request, send a javax.faces.ViewState parameter with the value ${ViewState}.
I spent a couple of ours finding this. I am not a JSF1.2 seasoned programmer but I hope it will help saving you time. The answer seems to be rigth, however I don't get the meaning of how do the XPath creation...
I just wanna to know how can I do the creation XPath on Jmeter (to use on jsf) pass by pass... (just like a tutorial) I read the text above but I can't get any the understanding....
The purpose is the same keep and use the javax.faces.ViewState
thanks in advance,

Answer 1

I have an additional question/problem.
Running JBOSS 4.2, JSF 1.2 and JMETER 2.3.2
Scenario 1 (SUCCESS):
I run one thread and one threadgroup, regex/xpath return the "ViewState" value correctly and the test runs perfectly until I stop it.
Scenarion 2 (FAILURE):
I run multiple threads and one threadgroup, regex/xpath eventually return the DEFAULT value instead the "ViewState" value to all but one thread. The more threads the faster they fail. It really seems like there is a threading issue.
In any case only one thread will remain running correctly.