记一次OOM内存溢出问题修复java.lang.OutOfMemoryError: Java heap space

• OutOfMemoryError
• • 1.使用article找到问题线程
  • 2.分析线程运行链路，找出问题代码位置
  • 3.使用堆文件确认问题

OutOfMemoryError

一大早过来上班项目启动后随意刷几个接口后服务就像卡主一样接口调不通了，然后就报错。
这里的思路是OOM一般都是由某个线程执行代码时创建对象过多导致占用大量的内存导致的，那好，那么我们就先找到这个造成问题的线程，再根据这个线程执行代码就可以找到问题点了，三步就能搞定。

org.springframework.web.util.NestedServletException: Handler dispatch failed; nested exception is java.lang.OutOfMemoryError: Java heap spaceat org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:982) ~[spring-webmvc-4.3.13.RELEASE.jar:4.3.13.RELEASE]at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901) ~[spring-webmvc-4.3.13.RELEASE.jar:4.3.13.RELEASE]at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970) [spring-webmvc-4.3.13.RELEASE.jar:4.3.13.RELEASE]at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861) [spring-webmvc-4.3.13.RELEASE.jar:4.3.13.RELEASE]at javax.servlet.http.HttpServlet.service(HttpServlet.java:635) [tomcat-embed-core-8.5.23.jar:8.5.23]at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846) [spring-webmvc-4.3.13.RELEASE.jar:4.3.13.RELEASE]at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) [tomcat-embed-core-8.5.23.jar:8.5.23]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) [tomcat-embed-core-8.5.23.jar:8.5.23]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.23.jar:8.5.23]at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) [tomcat-embed-websocket-8.5.23.jar:8.5.23]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.23.jar:8.5.23]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.23.jar:8.5.23]at com.alibaba.druid.support.http.WebStatFilter.doFilter(WebStatFilter.java:123) [druid-1.1.9.jar:1.1.9]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.23.jar:8.5.23]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.23.jar:8.5.23]at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) [spring-web-4.3.13.RELEASE.jar:4.3.13.RELEASE]at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.13.RELEASE.jar:4.3.13.RELEASE]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.23.jar:8.5.23]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.23.jar:8.5.23]at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:108) [spring-web-4.3.13.RELEASE.jar:4.3.13.RELEASE]at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.13.RELEASE.jar:4.3.13.RELEASE]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.23.jar:8.5.23]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.23.jar:8.5.23]at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81) [spring-web-4.3.13.RELEASE.jar:4.3.13.RELEASE]at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.13.RELEASE.jar:4.3.13.RELEASE]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.23.jar:8.5.23]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.23.jar:8.5.23]at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197) [spring-web-4.3.13.RELEASE.jar:4.3.13.RELEASE]at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.13.RELEASE.jar:4.3.13.RELEASE]at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-8.5.23.jar:8.5.23]at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-8.5.23.jar:8.5.23]at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199) [tomcat-embed-core-8.5.23.jar:8.5.23]at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-8.5.23.jar:8.5.23]at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:478) [tomcat-embed-core-8.5.23.jar:8.5.23]at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.23.jar:8.5.23]at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81) [tomcat-embed-core-8.5.23.jar:8.5.23]at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.23.jar:8.5.23]at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) [tomcat-embed-core-8.5.23.jar:8.5.23]at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803) [tomcat-embed-core-8.5.23.jar:8.5.23]at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.23.jar:8.5.23]at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868) [tomcat-embed-core-8.5.23.jar:8.5.23]at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1459) [tomcat-embed-core-8.5.23.jar:8.5.23]at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.23.jar:8.5.23]at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_181]at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_181]at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.23.jar:8.5.23]at java.lang.Thread.run(Thread.java:748) [na:1.8.0_181]
Caused by: java.lang.OutOfMemoryError: Java heap space

1.使用article找到问题线程

安装流程这里不做描述，请参考官网https://arthas.aliyun.com
启动article并监听我们的项目进程
使用thread命令就可以看到项目中所有的线程运行情况，我这里使用的是thread --state RUNNABLE，查看所有的运行中线程。果然找到有一个线程的运行情况有异常，cup运行状态101.55%

2.分析线程运行链路，找出问题代码位置

使用thread 374查看现场id为374的线程调用链路，我们发现代码执行到com.xt.util.DateUtils.timeList就结束了，结果发现有可能死循环的代码，修复代码后问题解决。

3.使用堆文件确认问题

一般情况做到上面就已经可以了，但是有时代码比较复杂，问题比较隐秘，不好直接从代码中找出问题。我们可以通过堆文件来分析，dump java heap, 类似 jmap 命令的 heap dump 功能。拿到hprof文件后使用jdk自带的分析工具jvisualvm.exe，这里我们看到堆中有大量的locaTime对象，与代码BUG吻合了。