HashMap在高并发下导致CPU过高

谁借莪１个温暖的怀抱￠ 2022-07-30 14:29 196阅读 0赞

**  先用top命令定位哪些线程占用多：**

top - 18:14:46 up 200 days, 23:26,  2 users,  load average: 95.13, 88.59, 79.51  
Tasks: 1528 total,   1 running, 1525 sleeping,   1 stopped,   1 zombie  
Cpu(s): 98.3%us,  0.1%sy,  0.0%ni,  1.5%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st  
Mem:  264351216k total, 178758300k used, 85592916k free,  1140796k buffers  
Swap: 16777208k total,        0k used, 16777208k free, 101647856k cached

PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND                             
48418 weblogic  20   0 28.9g 5.1g  11m R 97.8  2.0  42:17.14 java

**  然后用jstatck 48418 定位出线程堆栈48418换算成16进制是bd22，即与nid=0xbd22，可以看到是HashMap的问题，在高并发情况下，使用HashMap会导致CPU 过高的问题。**

"\[ACTIVE\] ExecuteThread: '8' for queue: 'weblogic.kernel.Default (self-tuning)'" daemon prio=10 tid=0x00007f472000c000 nid=0xbd22 runnable \[0x00007f479db6d000\]  
   java.lang.Thread.State: RUNNABLE  
        at java.util.HashMap.getEntry(HashMap.java:465)  
        at java.util.HashMap.containsKey(HashMap.java:449)  
        at com.gg.component.common.aop.init.TransactionMethodUtil.getTxMode(TransactionMethodUtil.java:120)  
        at com.gg.component.common.aop.proxy.TxProxy.doProxy(TxProxy.java:56)  
        at com.gg.component.common.aop.ProxyChain.doProxyChain(ProxyChain.java:117)  
        at com.gg.component.common.aop.ProxyManager.intercept(ProxyManager.java:57)  
        at com.gg.sys.client.facade.ClientUserFacade$$EnhancerByCGLIB$$e4f7c867.queryUserDirectlyByOrgId(<generated>)  
        at com.comtop.sproc.core.helper.SprocUserOrganizationHelper.queryUserInfosByOrgId(SprocUserOrganizationHelper.java:124)  
        at com.comtop.lcam.fwms.safety.safetysupervise.controller.SupervisePlanController.updateSupervisionPlanPlanType(SupervisePlanController.java:714)  
        at com.comtop.lcam.fwms.safety.safetysupervise.controller.SupervisePlanController$$FastClassByCGLIB$$5242a8b6.invoke(<generated>)  
        at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)  
        at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:698)  
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)  
        at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:80)  
        at com.comtop.lcam.fwms.monitor.MonitorAspect.aroundAllMethod(MonitorAspect.java:87)  
        at sun.reflect.GeneratedMethodAccessor726.invoke(Unknown Source)  
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)  
        at java.lang.reflect.Method.invoke(Method.java:606)  
        at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:621)  
        at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:610)  
        at org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:65)  
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)  
        at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:80)  
        at com.comtop.sproc.core.exceptionhandler.aop.SprocFacadeExceptionAspect.doAround(SprocFacadeExceptionAspect.java:45)  
        at sun.reflect.GeneratedMethodAccessor555.invoke(Unknown Source)  
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)  
        at java.lang.reflect.Method.invoke(Method.java:606)  
        at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:621)  
        at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:610)  
        at org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:65)  
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:161)  
        at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:91)  
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)  
        at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:631)  
        at com.comtop.lcam.fwms.safety.safetysupervise.controller.SupervisePlanController$$EnhancerByCGLIB$$19a36308.updateSupervisionPlanPlanType(<generated>)  
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)  
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)  
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)  
        at java.lang.reflect.Method.invoke(Method.java:606)  
        at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:219)  
        at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132)  
        at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)  
        at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:745)  
        at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:686)  
        at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80)  
        at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:925)  
        at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:856)  
        at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:936)  
        at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:838)  
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:751)  
        at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:812)  
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:844)  
        at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:280)  
        at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:254)  
        at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:136)  
        at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:341)  
        at weblogic.servlet.internal.TailFilter.doFilter(TailFilter.java:25)  
        at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:79)  
        at com.gg.sys.login.action.SessionFilter.doFilter(SessionFilter.java:219)  
        at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:79)  
        at com.comtop.sproc.system.filter.SprocRequestFilter.doFilter(SprocRequestFilter.java:62)  
        at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:79)  
        at com.gg.component.app.sna.SessionShareFilter.doFilter(SessionShareFilter.java:114)  
        at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:79)  
        at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)  
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)  
        at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:79)  
        at weblogic.servlet.internal.RequestEventsFilter.doFilter(RequestEventsFilter.java:27)  
        at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:79)  
        at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.wrapRun(WebAppServletContext.java:3388)  
        at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3354)  
        at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:321)  
        at weblogic.security.service.SecurityManager.runAs(SecurityManager.java:120)  
        at weblogic.servlet.provider.WlsSubjectHandle.run(WlsSubjectHandle.java:57)  
        at weblogic.servlet.internal.WebAppServletContext.doSecuredExecute(WebAppServletContext.java:2238)  
        at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2154)  
        at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:2132)  
        at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1564)  
        at weblogic.servlet.provider.ContainerSupportProviderImpl$WlsRequestExecutor.run(ContainerSupportProviderImpl.java:254)  
        at weblogic.work.ExecuteThread.execute(ExecuteThread.java:312)  
        at weblogic.work.ExecuteThread.run(ExecuteThread.java:264)

解决方案：

If multiple threads access a  HashMap concurrently and modify the map, it must be synchronized externally

To resolve this issue of corrupt  HashMap caused by asynchronous concurrent access is to do either of the following:

1. Synchronize objects using the  HashMap

2. Implement Concurrent HashMap instead of  HashMap.