What is an Unexpected End of Part error in ColdFusion?

Question

We are using Adobe ColdFusion 9 and are receiving the following error sporadically. I can not find any information on it. Does anyone have any ideas?

java.io.IOException: unexpected end of part
    at com.oreilly.servlet.multipart.PartInputStream.fill(PartInputStream.java:96)
    at com.oreilly.servlet.multipart.PartInputStream.read(PartInputStream.java:191)
    at com.oreilly.servlet.multipart.PartInputStream.read(PartInputStream.java:152)
    at com.oreilly.servlet.multipart.FilePart.write(FilePart.java:257)
    at com.oreilly.servlet.multipart.FilePart.writeTo(FilePart.java:215)
    at coldfusion.filter.FormScope.fillForm(FormScope.java:252)
    at coldfusion.filter.FusionContext.SymTab_initForRequest(FusionContext.java:376)
    at coldfusion.filter.GlobalsFilter.invoke(GlobalsFilter.java:33)
    at coldfusion.filter.DatasourceFilter.invoke(DatasourceFilter.java:22)
    at coldfusion.filter.CachingFilter.invoke(CachingFilter.java:53)
    at coldfusion.filter.RequestThrottleFilter.invoke(RequestThrottleFilter.java:126)
    at coldfusion.CfmServlet.service(CfmServlet.java:200)
    at coldfusion.bootstrap.BootstrapServlet.service(BootstrapServlet.java:89)
    at jrun.servlet.FilterChain.doFilter(FilterChain.java:86)
    at coldfusion.monitor.event.MonitoringServletFilter.doFilter(MonitoringServletFilter.java:42)
    at coldfusion.bootstrap.BootstrapFilter.doFilter(BootstrapFilter.java:46)
    at jrun.servlet.FilterChain.doFilter(FilterChain.java:94)
    at jrun.servlet.FilterChain.service(FilterChain.java:101)
    at jrun.servlet.ServletInvoker.invoke(ServletInvoker.java:106)
    at jrun.servlet.JRunInvokerChain.invokeNext(JRunInvokerChain.java:42)
    at jrun.servlet.JRunRequestDispatcher.invoke(JRunRequestDispatcher.java:286)
    at jrun.servlet.ServletEngineService.dispatch(ServletEngineService.java:543)
    at jrun.servlet.jrpp.JRunProxyService.invokeRunnable(JRunProxyService.java:203)
    at jrunx.scheduler.ThreadPool$DownstreamMetrics.invokeRunnable(ThreadPool.java:320)
    at jrunx.scheduler.ThreadPool$ThreadThrottle.invokeRunnable(ThreadPool.java:428)
    at jrunx.scheduler.ThreadPool$UpstreamMetrics.invokeRunnable(ThreadPool.java:266)
    at jrunx.scheduler.WorkerThread.run(WorkerThread.java:66)

09/22 11:41:43 error (JRun Service: ProxyService [jrun.servlet.jrpp.JRunProxyService@adc9df]) JRunPRoxyServer.invokeRunnable: 
java.lang.IllegalStateException
    at jrun.servlet.JRunResponse.getWriter(JRunResponse.java:205)
    at jrun.servlet.JRunResponse.sendError(JRunResponse.java:597)
    at jrun.servlet.JRunRequestDispatcher.invoke(JRunRequestDispatcher.java:328)
    at jrun.servlet.ServletEngineService.dispatch(ServletEngineService.java:543)
    at jrun.servlet.jrpp.JRunProxyService.invokeRunnable(JRunProxyService.java:203)
    at jrunx.scheduler.ThreadPool$DownstreamMetrics.invokeRunnable(ThreadPool.java:320)
    at jrunx.scheduler.ThreadPool$ThreadThrottle.invokeRunnable(ThreadPool.java:428)
    at jrunx.scheduler.ThreadPool$UpstreamMetrics.invokeRunnable(ThreadPool.java:266)
    at jrunx.scheduler.WorkerThread.run(WorkerThread.java:66)

java.lang.IllegalStateException
    at jrun.servlet.JRunResponse.getWriter(JRunResponse.java:205)
    at jrun.servlet.JRunResponse.sendError(JRunResponse.java:597)
    at jrun.servlet.JRunRequestDispatcher.invoke(JRunRequestDispatcher.java:328)
    at jrun.servlet.ServletEngineService.dispatch(ServletEngineService.java:543)
    at jrun.servlet.jrpp.JRunProxyService.invokeRunnable(JRunProxyService.java:203)
    at jrunx.scheduler.ThreadPool$DownstreamMetrics.invokeRunnable(ThreadPool.java:320)
    at jrunx.scheduler.ThreadPool$ThreadThrottle.invokeRunnable(ThreadPool.java:428)
    at jrunx.scheduler.ThreadPool$UpstreamMetrics.invokeRunnable(ThreadPool.java:266)
    at jrunx.scheduler.WorkerThread.run(WorkerThread.java:66)

Answer 1

I believe this is just a malformed multipart POST. It could happen for any number of reasons, the client crashing during the POST, the connection being dropped, etc.

Does this app do any (a lot?) of multipart form posts, like HTTP uploads?

I think it is benign, and you can probably ignore it. If you are getting a lot of them, as a percentage of total traffic, I suppose it could indicate some network/connection issues in your infrastructure.