關於解決Tomcat服務器Connection reset by peer 導致的宕機

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

首先貼出了服務器報錯信息，主要是服務器同時處理的請求超過了限制，導致宕機。總結出兩個方向去解決問題。

1. 修改連接超時時間connectionTimeout
2. 修改最大線程數及最大排隊數maxThreads、acceptCount

　　修改的文件均是Tomcat-》conf-》server.xml 

　　

 

　　

其中最后兩個參數意義如下：

maxThreads：tomcat起動的最大線程數，即同時處理的任務個數，默認值為200

acceptCount：當tomcat起動的線程數達到最大時，接受排隊的請求個數，默認值為100

 

這兩個值如何起作用，請看下面三種情況

情況1：接受一個請求，此時tomcat起動的線程數沒有到達maxThreads，tomcat會起動一個線程來處理此請求。

情況2：接受一個請求，此時tomcat起動的線程數已經到達maxThreads，tomcat會把此請求放入等待隊列，等待空閑線程。

情況3：接受一個請求，此時tomcat起動的線程數已經到達maxThreads，等待隊列中的請求個數也達到了acceptCount，此時tomcat會直接拒絕此次請求，返回connection refused

maxThreads如何配置

一般的服務器操作都包括量方面：1計算（主要消耗cpu），2等待（io、數據庫等）

第一種極端情況，如果我們的操作是純粹的計算，那么系統響應時間的主要限制就是cpu的運算能力，此時maxThreads應該盡量設的小，降低同一時間內爭搶cpu的線程個數，可以提高計算效率，提高系統的整體處理能力。

第二種極端情況，如果我們的操作純粹是IO或者數據庫，那么響應時間的主要限制就變為等待外部資源，此時maxThreads應該盡量設的大，這樣才能提高同時處理請求的個數，從而提高系統整體的處理能力。此情況下因為tomcat同時處理的請求量會比較大，所以需要關注一下tomcat的虛擬機內存設置和linux的open file限制。