关于解决Tomcat服务器Connection reset by peer 导致的宕机

org.apache.catalina.connector.ClientAbortException: java.io.IOException: Connection reset by peer
    at org.apache.catalina.connector.OutputBuffer.realWriteBytes(OutputBuffer.java:407)
    at org.apache.tomcat.util.buf.ByteChunk.flushBuffer(ByteChunk.java:480)
    at org.apache.tomcat.util.buf.ByteChunk.append(ByteChunk.java:366)
    at org.apache.catalina.connector.OutputBuffer.writeBytes(OutputBuffer.java:432)
    at org.apache.catalina.connector.OutputBuffer.write(OutputBuffer.java:420)
    at org.apache.catalina.connector.CoyoteOutputStream.write(CoyoteOutputStream.java:91)
    at com.dtxxsoft.spm.sys.controller.SpmUploadFileController.download(SpmUploadFileController.java:299)
    at sun.reflect.GeneratedMethodAccessor1477.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.chinasofti.ro.bizframework.core.utils.ActionInvokerUtil.invoke(ActionInvokerUtil.java:207)
    at com.chinasofti.ro.bizframework.core.mvc.ActionInvoker.invoke(ActionInvoker.java:181)
    at com.chinasofti.ro.bizframework.core.mvc.ActionFilter.doFilter(ActionFilter.java:179)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at com.chinasofti.ro.bizframework.core.web.filter.DisableUrlSessionFilter.doFilter(DisableUrlSessionFilter.java:59)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at com.chinasofti.ro.bizframework.core.web.filter.LocaleFilter.doFilterInternal(LocaleFilter.java:65)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:96)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at com.dtxxsoft.spm.sys.filter.SSOFilter.doFilter(SSOFilter.java:162)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at com.chinasofti.ro.bizframework.core.web.filter.InitialFilter.doFilter(InitialFilter.java:70)
    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:505)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
    at com.googlecode.psiprobe.Tomcat70AgentValve.invoke(Tomcat70AgentValve.java:38)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:436)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1078)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1749)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1708)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Thread.java:748)
Caused by: java.io.IOException: Connection reset by peer
    at sun.nio.ch.FileDispatcherImpl.write0(Native Method)
    at sun.nio.ch.SocketDispatcher.write(SocketDispatcher.java:47)
    at sun.nio.ch.IOUtil.writeFromNativeBuffer(IOUtil.java:93)
    at sun.nio.ch.IOUtil.write(IOUtil.java:65)
    at sun.nio.ch.SocketChannelImpl.write(SocketChannelImpl.java:471)
    at org.apache.tomcat.util.net.NioChannel.write(NioChannel.java:125)
    at org.apache.tomcat.util.net.NioBlockingSelector.write(NioBlockingSelector.java:101)
    at org.apache.tomcat.util.net.NioSelectorPool.write(NioSelectorPool.java:174)
    at org.apache.coyote.http11.InternalNioOutputBuffer.writeToSocket(InternalNioOutputBuffer.java:163)
    at org.apache.coyote.http11.InternalNioOutputBuffer.flushBuffer(InternalNioOutputBuffer.java:242)
    at org.apache.coyote.http11.InternalNioOutputBuffer.addToBB(InternalNioOutputBuffer.java:213)
    at org.apache.coyote.http11.InternalNioOutputBuffer.access$000(InternalNioOutputBuffer.java:41)
    at org.apache.coyote.http11.InternalNioOutputBuffer$SocketOutputBuffer.doWrite(InternalNioOutputBuffer.java:268)
    at org.apache.coyote.http11.filters.ChunkedOutputFilter.doWrite(ChunkedOutputFilter.java:119)
    at org.apache.coyote.http11.AbstractOutputBuffer.doWrite(AbstractOutputBuffer.java:192)
    at org.apache.coyote.Response.doWrite(Response.java:499)
    at org.apache.catalina.connector.OutputBuffer.realWriteBytes(OutputBuffer.java:402)
    ... 48 more

首先贴出了服务器报错信息，主要是服务器同时处理的请求超过了限制，导致宕机。总结出两个方向去解决问题。

1. 修改连接超时时间connectionTimeout
2. 修改最大线程数及最大排队数maxThreads、acceptCount

　　修改的文件均是Tomcat-》conf-》server.xml

　　

　　

其中最后两个参数意义如下：

maxThreads：tomcat起动的最大线程数，即同时处理的任务个数，默认值为200

acceptCount：当tomcat起动的线程数达到最大时，接受排队的请求个数，默认值为100

这两个值如何起作用，请看下面三种情况

情况1：接受一个请求，此时tomcat起动的线程数没有到达maxThreads，tomcat会起动一个线程来处理此请求。

情况2：接受一个请求，此时tomcat起动的线程数已经到达maxThreads，tomcat会把此请求放入等待队列，等待空闲线程。

情况3：接受一个请求，此时tomcat起动的线程数已经到达maxThreads，等待队列中的请求个数也达到了acceptCount，此时tomcat会直接拒绝此次请求，返回connection refused

maxThreads如何配置

一般的服务器操作都包括量方面：1计算（主要消耗cpu），2等待（io、数据库等）

第一种极端情况，如果我们的操作是纯粹的计算，那么系统响应时间的主要限制就是cpu的运算能力，此时maxThreads应该尽量设的小，降低同一时间内争抢cpu的线程个数，可以提高计算效率，提高系统的整体处理能力。

第二种极端情况，如果我们的操作纯粹是IO或者数据库，那么响应时间的主要限制就变为等待外部资源，此时maxThreads应该尽量设的大，这样才能提高同时处理请求的个数，从而提高系统整体的处理能力。此情况下因为tomcat同时处理的请求量会比较大，所以需要关注一下tomcat的虚拟机内存设置和linux的open file限制。