SEVERE: Servlet.service() for servlet [CfmServlet] in context with path [/] threw exception

[haxtbh]

We have been running CF 11 U5 for a while now with no problems at all. We run CF Enterprise on IIS 8.5 on Server 2k12 64bit.

Recently a few of our clients have been complaining that when they upload files via our various methods of file uploads they get errors back. These errors are browser errors telling them connection has been reset, or page cannot be display etc.

This only seems to happen once the file size goes above 300-400kb. We have no restrictions in IIS as 95% of our other clients have no trouble uploading files up to 200MB.

Nothing has changed to any of the code that runs these uploads. We have a mixture of standard pages with form post which CF then uploads the image to some pages that use jquery file upload plugins which post to CF pages that do the upload.

It doesn't seem that anything is ever uploaded and the user gets the error back pretty quickly within 2-5 seconds of starting the upload. The uploaded files are usual images (jpg) or zip files.

This only seems to affect a limited amount of people as well. When every I try to replicate the issue uploading the same files from my side  I never see the problem and everything works as intended. A lot of our other clients have no issues uploading either.

Looking at the IIS logs they are getting a 400 error. Failed request logs tell me its a bad request.

When looking at the Coldfusion error log I get the following error:

Oct 07, 2015 9:56:53 AM org.apache.catalina.core.StandardWrapperValve invoke

SEVERE: Servlet.service() for servlet [CfmServlet] in context with path [/] threw exception

java.io.IOException: Socket read failed

  at org.apache.coyote.ajp.AjpProcessor.read(AjpProcessor.java:325)

  at org.apache.coyote.ajp.AjpProcessor.readMessage(AjpProcessor.java:447)

  at org.apache.coyote.ajp.AjpProcessor.receive(AjpProcessor.java:343)

  at org.apache.coyote.ajp.AbstractAjpProcessor.refillReadBuffer(AbstractAjpProcessor.java:685)

  at org.apache.coyote.ajp.AbstractAjpProcessor$SocketInputBuffer.doRead(AbstractAjpProcessor.java:1209)

  at org.apache.coyote.Request.doRead(Request.java:430)

  at org.apache.catalina.connector.InputBuffer.realReadBytes(InputBuffer.java:290)

  at org.apache.tomcat.util.buf.ByteChunk.substract(ByteChunk.java:449)

  at org.apache.catalina.connector.InputBuffer.read(InputBuffer.java:315)

  at org.apache.catalina.connector.CoyoteInputStream.read(CoyoteInputStream.java:200)

  at com.oreilly.servlet.multipart.BufferedServletInputStream.fill(BufferedServletInputStream.java:64)

  at com.oreilly.servlet.multipart.BufferedServletInputStream.readLine(BufferedServletInputStream.java:108)

  at com.oreilly.servlet.multipart.LimitedServletInputStream.readLine(LimitedServletInputStream.java:60)

  at com.oreilly.servlet.multipart.PartInputStream.fill(PartInputStream.java:93)

  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:252)

  at com.oreilly.servlet.multipart.FilePart.writeTo(FilePart.java:211)

  at coldfusion.filter.FormScope.fillForm(FormScope.java:338)

  at coldfusion.filter.FusionContext.SymTab_initForRequest(FusionContext.java:512)

  at coldfusion.filter.GlobalsFilter.invoke(GlobalsFilter.java:33)

  at coldfusion.filter.DatasourceFilter.invoke(DatasourceFilter.java:22)

  at coldfusion.filter.CachingFilter.invoke(CachingFilter.java:62)

  at coldfusion.filter.RequestThrottleFilter.invoke(RequestThrottleFilter.java:151)

  at coldfusion.CfmServlet.service(CfmServlet.java:219)

  at coldfusion.bootstrap.BootstrapServlet.service(BootstrapServlet.java:89)

  at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)

  at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)

  at coldfusion.monitor.event.MonitoringServletFilter.doFilter(MonitoringServletFilter.java:42)

  at coldfusion.bootstrap.BootstrapFilter.doFilter(BootstrapFilter.java:46)

  at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)

  at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)

  at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)

  at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)

  at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)

  at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)

  at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)

  at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)

  at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:422)

  at org.apache.coyote.ajp.AjpProcessor.process(AjpProcessor.java:199)

  at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607)

  at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:314)

  at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)

  at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)

  at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)

  at java.lang.Thread.run(Unknown Source)

This error is where I am stumped. What could cause this error for a select few people uploading files?

Any ideas?