Hi, I have a rpc type webservice. I works perfectly but I tried to do stress tests so I ran 20 calling my webservice with the same args. After some time, the request created(I logged the request on the client side with an handler), is false. Correct is : ... <env:body> <ns1:getSettings xmlns:ns1='http://mycompany.com'> <String_1 xmlns=''>AAAAA</String_1> <String_2 xmlns=''>BBBBB</String_2> </ns1:getSettings> </env:body> wrong is : ... <env:body> <ns1:getSettings xmlns:ns1='http://mycompany.com'> <String_1 xmlns='' xmlns:xsi='http://www.w3c.org/2001/XMLSchema-instance' xsi:nil='1' /> <String_2 xmlns=''>BBBBB</String_2> </ns1:getSettings> </env:body> or ... <env:body> <ns1:getSettings xmlns:ns1='http://mycompany.com'> <String_1 xmlns=''>AAAAA</String_1> <String_2 xmlns='' xmlns:xsi='http://www.w3c.org/2001/XMLSchema-instance' xsi:nil='1' /> </ns1:getSettings> </env:body> I don't understand why this happens because I execute the axact same code on the client and server side. I found no issue on jira. For me this problem is easily repoducible as soon as I have at least 10 threads calling the ws concurrently. Thanks, Vincent. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3983668#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...