Socket read failedが原因の FileUploadException が発生する

Issue

server.log ログに以下のエラーが発生しています。この問題が発生している原因は何ですか? 調整が必要なタイムアウト値はありますか?

2011-10-27 14:25:43,095 ERROR [org.apache.struts.upload.CommonsMultipartRequestHandler] (ajp-10.20.30.40-1001-8) Failed to parse multipart request
org.apache.commons.fileupload.FileUploadException
    at org.apache.commons.fileupload.FileUploadBase.parseRequest(FileUploadBase.java:369)
    at org.apache.commons.fileupload.FileUploadBase.parseRequest(FileUploadBase.java:302)
    at org.apache.struts.upload.CommonsMultipartRequestHandler.handleRequest(CommonsMultipartRequestHandler.java:193)
    at org.apache.struts.util.RequestUtils.populate(RequestUtils.java:442)
    at org.apache.struts.action.RequestProcessor.processPopulate(RequestProcessor.java:816)
    at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:203)
    at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
    at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
   ......
    at org.apache.coyote.ajp.AjpProcessor.process(AjpProcessor.java:436)
    at org.apache.coyote.ajp.AjpProtocol$AjpConnectionHandler.process(AjpProtocol.java:384)
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:451)
    at java.lang.Thread.run(Thread.java:619)
Caused by:
ClientAbortException:java.io.IOException:Socket read failed
    at org.apache.catalina.connector.InputBuffer.realReadBytes(InputBuffer.java:342)
    at org.apache.tomcat.util.buf.ByteChunk.substract(ByteChunk.java:420)
    at org.apache.catalina.connector.InputBuffer.read(InputBuffer.java:364)
    at org.apache.catalina.connector.CoyoteInputStream.read(CoyoteInputStream.java:193)
    at org.apache.commons.fileupload.MultipartStream$ItemInputStream.makeAvailable(MultipartStream.java:959)
    at org.apache.commons.fileupload.MultipartStream$ItemInputStream.read(MultipartStream.java:887)
    at java.io.InputStream.read(InputStream.java:85)
    at org.apache.commons.fileupload.util.Streams.copy(Streams.java:94)
    ......
    at org.apache.struts.upload.CommonsMultipartRequestHandler.handleRequest(CommonsMultipartRequestHandler.java:193)
    at org.apache.struts.util.RequestUtils.populate(RequestUtils.java:442)
    at org.apache.struts.action.RequestProcessor.processPopulate(RequestProcessor.java:816)
    at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:203)
    at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
    at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    ......
    at java.lang.Thread.run(Thread.java:619)
Caused by: java.io.IOException:Socket read failed
    at org.apache.coyote.ajp.AjpProcessor.read(AjpProcessor.java:1040)
    at org.apache.coyote.ajp.AjpProcessor.readMessage(AjpProcessor.java:1115)
    at org.apache.coyote.ajp.AjpProcessor.receive(AjpProcessor.java:1057)
    at org.apache.coyote.ajp.AjpProcessor.refillReadBuffer(AjpProcessor.java:1095)
    at org.apache.coyote.ajp.AjpProcessor.access$000(AjpProcessor.java:58)
    at org.apache.coyote.ajp.AjpProcessor$SocketInputBuffer.doRead(AjpProcessor.java:1181)
    at org.apache.coyote.Request.doRead(Request.java:428)
    at org.apache.catalina.connector.InputBuffer.realReadBytes(InputBuffer.java:332)
    ...67 more