I was running the petclinic example that was created with spring roo, also I test booking-mvc example that comes whit spring webflow 2.0.9 and the same happens, this is when I reload the main page many times.

If I remove the lines from both examples there is no error.

< spring:theme code="styleSheet" var="theme_css"/>
            <spring:url value="/${theme_css}" var="theme_css_url"/>


            <spring:url value="/resources/dojo/dojo.js" var="dojo_url"/>
            <spring:url value="/resources/dijit/themes/tundra/tundra.css" var="tundra_url"/>
            <spring:url value="/resources/spring/Spring.js" var="spring_url"/>
            <spring:url value="/resources/spring/Spring-Dojo.js" var="spring_dojo_url"/>
            <spring:url value="/static/images/favicon.ico" var="favicon" />
            <link rel="stylesheet" type="text/css" media="screen" href="${theme_css_url}"><!-- //required for FF3 and Opera --></link>
            <link rel="stylesheet" type="text/css" href="${tundra_url}"><!-- //required for FF3 and Opera --></link>
            <link rel="SHORTCUT ICON" href="${favicon}" />


            <script src="${dojo_url}" type="text/javascript" ><!-- //required for FF3 and Opera --></script>
            <script src="${spring_url}" type="text/javascript"><!-- //required for FF3 and Opera --></script>
            <script src="${spring_dojo_url}" type="text/javascript"><!-- //required for FF3 and Opera --></script>
            <script language="JavaScript" type="text/javascript">dojo.require("dojo.parser");</script>

So I can deduce that this is something related with this servlet

   <servlet>
        <servlet-name>Resource Servlet</servlet-name>
        <servlet-class>org.springframework.js.resource.ResourceServlet</servlet-class>
    </servlet>


    <!--
                Map all /resources requests to the Resource Servlet for handling
        -->
    <servlet-mapping>
        <servlet-name>Resource Servlet</servlet-name>
        <url-pattern>/resources/*</url-pattern>
    </servlet-mapping>

Running the example injetty 6.1.10, tomcat 1.6, in fedora 12 with java 1.6.20, make errors. but in aix and websphere no errors, and tomcat 1.6 and windows no errors, I think that this is something related with linux.

STACKTRACE
    2010-05-21 12:53:07.733::WARN:  Nested in org.springframework.web.util.NestedServletException: Request processing failed; nested exception is org.apache.tiles.impl.CannotRenderException: ServletException including path '/WEB-INF/layouts/default.jspx'.:
        org.apache.tiles.impl.CannotRenderException: ServletException including path '/WEB-INF/layouts/default.jspx'.
         at org.apache.tiles.impl.BasicTilesContainer.render(BasicTilesContainer.java:691)
         at org.apache.tiles.impl.BasicTilesContainer.render(BasicTilesContainer.java:643)
         at org.apache.tiles.impl.BasicTilesContainer.render(BasicTilesContainer.java:626)
         at org.apache.tiles.impl.BasicTilesContainer.render(BasicTilesContainer.java:322)
         at org.springframework.web.servlet.view.tiles2.TilesView.renderMergedOutputModel(TilesView.java:100)
         at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:250)
         at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1060)
         at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:798)
         at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:716)
         at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:647)
         at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:552)
         at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
         at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
         at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487)
         at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:362)
         at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
         at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)
         at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:726)
         at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:405)
         at org.mortbay.jetty.servlet.Dispatcher.forward(Dispatcher.java:285)
         at org.mortbay.jetty.servlet.Dispatcher.error(Dispatcher.java:135)
         at org.mortbay.jetty.servlet.ErrorPageErrorHandler.handle(ErrorPageErrorHandler.java:121)
         at org.mortbay.jetty.Response.sendError(Response.java:274)
         at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:429)
         at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
         at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)
         at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:726)
         at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:405)
         at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:206)
         at org.mortbay.jetty.handler.HandlerCollection.handle(HandlerCollection.java:114)
         at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
         at org.mortbay.jetty.Server.handle(Server.java:324)
         at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:505)
         at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:829)
         at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:514)
         at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:211)
         at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:380)
         at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:395)
         at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:488)
        Caused by: org.apache.tiles.util.TilesIOException: ServletException including path '/WEB-INF/layouts/default.jspx'.
         at org.apache.tiles.servlet.context.ServletUtil.wrapServletException(ServletUtil.java:232)
         at org.apache.tiles.servlet.context.ServletTilesRequestContext.forward(ServletTilesRequestContext.java:243)
         at org.apache.tiles.servlet.context.ServletTilesRequestContext.dispatch(ServletTilesRequestContext.java:222)
         at org.apache.tiles.renderer.impl.TemplateAttributeRenderer.write(TemplateAttributeRenderer.java:44)
         at org.apache.tiles.renderer.impl.AbstractBaseAttributeRenderer.render(AbstractBaseAttributeRenderer.java:103)
         at org.apache.tiles.impl.BasicTilesContainer.render(BasicTilesContainer.java:669)
         at org.apache.tiles.impl.BasicTilesContainer.render(BasicTilesContainer.java:689)
         ... 38 more
        Caused by: java.io.FileNotFoundException: /home/tsalazar/Workspace/test/roo_clinic/src/main/webapp/WEB-INF/web.xml (Too many open files)
         at java.io.FileInputStream.open(Native Method)
         at java.io.FileInputStream.<init>(FileInputStream.java:106)
         at java.io.FileInputStream.<init>(FileInputStream.java:66)
         at sun.net.www.protocol.file.FileURLConnection.connect(FileURLConnection.java:70)
         at sun.net.www.protocol.file.FileURLConnection.getInputStream(FileURLConnection.java:161)
         at java.net.URL.openStream(URL.java:1010)
         at org.apache.jasper.compiler.JspConfig.processWebDotXml(JspConfig.java:114)
         at org.apache.jasper.compiler.JspConfig.init(JspConfig.java:295)
         at org.apache.jasper.compiler.JspConfig.findJspProperty(JspConfig.java:360)
         at org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:141)
         at org.apache.jasper.compiler.Compiler.compile(Compiler.java:409)
         at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:592)
         at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:344)
         at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:470)
         at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:364)
         at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
         at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487)
         at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:362)
         at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
         at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)
         at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:726)
         at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:405)
         at org.mortbay.jetty.servlet.Dispatcher.forward(Dispatcher.java:285)
         at org.mortbay.jetty.servlet.Dispatcher.forward(Dispatcher.java:126)
         at org.apache.tiles.servlet.context.ServletTilesRequestContext.forward(ServletTilesRequestContext.java:241)
         ... 43 more