Openfire keeping the session alive even if client disconnect from chat

Hi, i am building a Chat application using Openfire and Strophe.js

During test, 800 concurrent connections were established and then i closed the browser. After waiting even 30 minutes, Openfire still shows users are connected in Room

xmpp.client.idle = 360000

i checked the error, info and warn log files. All i found is hundreds of this line in  'Info.log'

org.jivesoftware.openfire.http.HttpBindServlet - Root element 'body' does not contain a SID attribute value in parsed request data from

any help would be highly appreciated