Un-synchronizing the portlet rendering UP-1424 exposed a new issue with portlets that use JSPs to render. There is a race condition that causes the content from one portlet to appear in multiple, unrelated portlets that also use JSPs on the same page.

The cause is Tomcat un-wrapping the HttpServletRequest past the request attribute scoping wrapper added for each uPortal channel rendering thread. With only one place to store request attributes and multiple threads rendering JSPs at the same time the JSP rendering request attributes get overwritten by each thread starting rendering.