Stateful bean was removed or timed out.

超时时间设置为30分钟，但是不到10分钟后再去访问该Stateful bean，就发现该bean已经不存在了，
日志如下：
Caused by: javax.ejb.NoSuchEJBException: Stateful bean BeanId(spms-ear#spms-ejb.jar#MesysRoleActionBean, AB28C028-0125-4000-E000-0364805A011F) was removed or timed out.
at com.ibm.ejs.container.activator.StatefulSessionActivationStrategy.atActivate(StatefulSessionActivationStrategy.java:241)
at com.ibm.ejs.container.activator.Activator.activateBean(Activator.java:599)
at com.ibm.ejs.container.EJSContainer.preInvokeActivate(EJSContainer.java:3919)
at com.ibm.ejs.container.EJSContainer.EjbPreInvoke(EJSContainer.java:3304)
at com.spms.mesys.action.EJSLocal0SFMesysRoleActionBean_14738250.getCodes(EJSLocal0SFMesysRoleActionBean_14738250.java)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:45)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37)
at java.lang.reflect.Method.invoke(Method.java:599)
at org.jboss.seam.util.Reflections.invoke(Reflections.java:22)
at org.jboss.seam.intercept.RootInvocationContext.proceed(RootInvocationContext.java:32)
at org.jboss.seam.intercept.ClientSideInterceptor$1.proceed(ClientSideInterceptor.java:76)
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:56)
at org.jboss.seam.security.SecurityInterceptor.aroundInvoke(SecurityInterceptor.java:163)
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
at org.jboss.seam.ejb.RemoveInterceptor.aroundInvoke(RemoveInterceptor.java:43)
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
at org.jboss.seam.core.SynchronizationInterceptor.aroundInvoke(SynchronizationInterceptor.java:32)
at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
at org.jboss.seam.intercept.RootInterceptor.invoke(RootInterceptor.java:107)
at org.jboss.seam.intercept.ClientSideInterceptor.invoke(ClientSideInterceptor.java:54)
at org.javassist.tmp.java.lang.Object_$$_javassist_seam_21.getCodes(Object_$$_javassist_seam_21.java)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:45)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37)
at java.lang.reflect.Method.invoke(Method.java:599)
at javax.el.BeanELResolver.getValue(BeanELResolver.java:273)
at javax.el.CompositeELResolver.getValue(CompositeELResolver.java:143)
at com.sun.faces.el.FacesCompositeELResolver.getValue(FacesCompositeELResolver.java:73)
at org.jboss.el.parser.AstPropertySuffix.getValue(AstPropertySuffix.java:53)
at org.jboss.el.parser.AstValue.getValue(AstValue.java:67)
at org.jboss.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:186)
at com.sun.facelets.el.TagValueExpression.getValue(TagValueExpression.java:71)
... 62 more