奇怪的exception：NoRouteToHostException

最近出现这个后：HTTP/1.1 requires host
就频繁的出现：
    [10:44:35.830] java.net.NoRouteToHostException: Write failed: Connection timed out
[10:44:35.830]  at jrockit.net.SocketNativeIO.writeBytesPinned(Native Method)
[10:44:35.830]  at jrockit.net.SocketNativeIO.socketWrite(SocketNativeIO.java:73)
[10:44:35.830]  at java.net.SocketOutputStream.socketWrite0(SocketOutputStream.java)
[10:44:35.830]  at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:92)
[10:44:35.830]  at java.net.SocketOutputStream.write(SocketOutputStream.java:136)
[10:44:35.830]  at com.caucho.vfs.SocketStream.write(SocketStream.java:210)
[10:44:35.830]  at com.caucho.vfs.WriteStream.write(WriteStream.java:309)
[10:44:35.830]  at com.caucho.server.connection.ResponseStream.writeNext(ResponseStream.java:448)
[10:44:35.830]  at com.caucho.server.connection.ToByteResponseStream.write(ToByteResponseStream.java:329)
[10:44:35.830]  at com.caucho.server.connection.ServletOutputStreamImpl.write(ServletOutputStreamImpl.java:68)
[10:44:35.830]  at com.caucho.vfs.Path.writeToStream(Path.java:1073)
[10:44:35.830]  at com.caucho.servlets.FileServlet.service(FileServlet.java:351)
[10:44:35.830]  at com.caucho.server.dispatch.ServletFilterChain.doFilter(ServletFilterChain.java:106)
[10:44:35.830]  at org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:413)
[10:44:35.830]  at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:70)
[10:44:35.830]  at org.apache.struts2.dispatcher.ActionContextCleanUp.doFilter(ActionContextCleanUp.java:99)
[10:44:35.830]  at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:70)
[10:44:35.830]  at org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:738)
[10:44:35.830]  at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:70)
[10:44:35.830]  at com.caucho.server.webapp.WebAppFilterChain.doFilter(WebAppFilterChain.java:173)
[10:44:35.830]  at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:229)
[10:44:35.830]  at com.caucho.server.http.HttpRequest.handleRequest(HttpRequest.java:274)
[10:44:35.830]  at com.caucho.server.port.TcpConnection.run(TcpConnection.java:514)
[10:44:35.830]  at com.caucho.util.ThreadPool.runTasks(ThreadPool.java:520)
[10:44:35.830]  at com.caucho.util.ThreadPool.run(ThreadPool.java:442)
[10:44:35.830]  at java.lang.Thread.run(Thread.java:595)


服务器用resin，java是1.5（64bit）的。
查不出原因，苦脑啊

我知道原因啦，应该是其中一个原因，因为我的resin压力太大，负荷不过，导致出现这个问题，配置了apach帮resin分担压力就没事啦