session object is null, but not always.

[angad-rajput-qp]

I am using resin as a web server and hazelcast-wm 4.0 and hazelcast 4.0
I receive a NullPointerException on the session object. The error does not reappear after we refresh.
The session object is randomly null for the first time.

Code in a JSP:

user = (User) session.getAttribute("user");

Error:

java.lang.NullPointerException
                                                       	at _jsp._jsp._user._socialNetworksites__jsp._jspService(_socialNetworksites__jsp.java:1444)
                                                       	at _jsp._jsp._user._socialNetworksites__jsp._jspService(_socialNetworksites__jsp.java:1393)
                                                       	at com.caucho.jsp.JavaPage.service(JavaPage.java:64)
                                                       	at com.caucho.jsp.Page.pageservice(Page.java:548)
                                                       	at com.caucho.server.dispatch.PageFilterChain.doFilter(PageFilterChain.java:194)
                                                       	at com.hazelcast.web.WebFilter.doFilter(WebFilter.java:305)
                                                       	at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:89)
                                                       	at com.caucho.server.httpcache.ProxyCacheFilterChain.doFilter(ProxyCacheFilterChain.java:161)
                                                       	at com.caucho.server.webapp.DispatchFilterChain.doFilter(DispatchFilterChain.java:131)
                                                       	at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:314)
                                                       	at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:440)
                                                       	at com.caucho.server.webapp.RequestDispatcherImpl.include(RequestDispatcherImpl.java:359)
                                                       	at com.hazelcast.web.WebFilter$HazelcastRequestWrapper$1.include(WebFilter.java:370)
                                                       	at com.hazelcast.web.WebFilter$HazelcastRequestWrapper$1.include(WebFilter.java:370)
                                                       	at com.hazelcast.web.WebFilter$HazelcastRequestWrapper$1.include(WebFilter.java:370)
                                                       	at com.caucho.jsp.PageContextImpl.include(PageContextImpl.java:1091)
                                                       	at _jsp._jsp._user._qp_22dlogin__jsp._jspService(_qp_22dlogin__jsp.java:1609)
                                                       	at _jsp._jsp._user._qp_22dlogin__jsp._jspService(_qp_22dlogin__jsp.java:1394)

the session is null in the above case.

--EDIT--

I tried fetching "request.getSession(true)" and it gave me null randomly.