应用系统瓶颈排查和分析的思考-Arthas 实战

2020-09-02 628

作者 | 一啦米

【Arthas 官方社区正在举行征文活动，参加即有奖品拿~点击投稿】

背景

业务应用系统接入流程引擎来处理业务应用的流程执行，流程引擎提供多线程高性能异步化来执行流程元素的执行，但是如何设置流程引擎的线程池线程数执行，以及执行线程数和任务数，应用机器资源使用情况之间的关系如何，目前只能通过接入方的人工经验评估，比较粗泛评估，参数的合理性也很难直观的评估，现通过现有的应用系统默认的参数配置进行问题说明。

性能监控

查看 CPU 核数

应用机器的配置是 2 核 CPU 配置：

查看应用机器的负载情况

应用程序的近 15 分钟内的负载严重的超载(平均超出 CPU 执行的 10 倍之多)，应用程序对应的 CPU 和 MEM 的利用率都很高，按照本次单机模拟线上的流量（QPS：10) 不至于出现如此的负载情况吧。

查看应用机器的综合统计

CPU 运行队列中也严重的堵筛(Procs列中指标），应用的 CPU 有效利用率其实并不算太高（US+SY),但是系统出现了严重的 CS(上下文切换)，配合 BI，BO 执行，也间接反馈出一些端倪，具体反馈到应用程序中，还需要进一步分析。

查看应用服务(PID=512)的进程 CPU 执行情况

查看应用机器的磁盘 IO 使用情况

应用系统的线程统计概要

应用系统中居然有如此多的线程(1285),应用系统接入流程 SDK 中的线程池数据设置也不会超过80个线程，为何有如何大的偏差，考虑到应用系统中还存在 RPC，kafka 等相关的技术栈，对于应用系统的线程分布还需要进一步的分析。

应用系统执行 dashboard

GC 回收线程监控统计

应用系统线程执行栈的统计

阻塞线程 ThreadDump 信息

org.apache.log4j.spi.RootLogger is blocking 379 threads.

Pigeon-Server-Request-Processor-46-thread-318
Stack Trace is:
java.lang.Thread.State: RUNNABLE
at java.lang.Throwable.printStackTrace(Throwable.java:665)

locked <0x000000075332fde8> (a java.io.PrintWriter)

java.lang.Throwable.printStackTrace(Throwable.java:721)

at org.apache.log4j.DefaultThrowableRenderer.render(DefaultThrowableRenderer.java:60)
at org.apache.log4j.spi.ThrowableInformation.getThrowableStrRep(ThrowableInformation.java:87)

locked <0x000000074ae96550> (a org.apache.log4j.spi.ThrowableInformation)

org.apache.log4j.spi.LoggingEvent.getThrowableStrRep(LoggingEvent.java:413)

at org.apache.log4j.WriterAppender.subAppend(WriterAppender.java:313)
at org.apache.log4j.WriterAppender.append(WriterAppender.java:162)
at com.dianping.combiz.misc.ExtendedConsoleAppender.append(ExtendedConsoleAppender.java:82)
at org.apache.log4j.AppenderSkeleton.doAppend(AppenderSkeleton.java:251)

eliminated <0x000000075f880030> (a com.dianping.combiz.misc.ExtendedConsoleAppender)

com.dianping.combiz.misc.ExtendedConsoleAppender.doAppend(ExtendedConsoleAppender.java:75)

locked <0x000000075f880030> (a com.dianping.combiz.misc.ExtendedConsoleAppender)

org.apache.log4j.helpers.AppenderAttachableImpl.appendLoopOnAppenders(AppenderAttachableImpl.java:66)

at org.apache.log4j.Category.callAppenders(Category.java:206)
- locked <0x000000075ed2bd58> (a org.apache.log4j.spi.RootLogger)
at org.apache.log4j.Category.forcedLog(Category.java:391)
at org.apache.log4j.Category.log(Category.java:856)
at org.slf4j.impl.Log4jLoggerAdapter.error(Log4jLoggerAdapter.java:576)
at com.meituan.mafka.client.producer.DefaultProducerProcessor.doSend(DefaultProducerProcessor.java:832)
at com.meituan.mafka.client.producer.DefaultProducerProcessor.sendMessage(DefaultProducerProcessor.java:603)
at com.meituan.mafka.client.producer.DefaultProducerProcessor.sendMessage(DefaultProducerProcessor.java:584)
at com.meituan.mafka.client.producer.DefaultProducerProcessor.sendMessage(DefaultProducerProcessor.java:567)
at com.meituan.mafka.client.producer.DefaultProducerProcessor.sendMessage(DefaultProducerProcessor.java:562)
at com.dianping.poi.flowcenter.mq.WorkflowEventMQProducer.sendSyncMessage(WorkflowEventMQProducer.java:98)
at com.dianping.poi.flowcenter.WorkflowEngine.createFlowInstance(WorkflowEngine.java:642)
at com.dianping.poi.flowcenter.WorkflowEngine.startWorkflow0(WorkflowEngine.java:560)
at com.dianping.poi.flowcenter.WorkflowEngine.startWorkflow(WorkflowEngine.java:504)
at com.dianping.poi.mainflow.clearengine.engine.create.impl.CreateWorkflowServiceImpl.createWorkflow(CreateWorkflowServiceImpl.java:66)
at com.dianping.poi.mainflow.core.business.WorkflowBusiness.createWorkflow(WorkflowBusiness.java:277)
at com.dianping.poi.mainflow.core.business.WorkflowBusiness.createWorkflow(WorkflowBusiness.java:183)
at com.dianping.poi.mainflow.core.business.WorkflowBusiness.createWorkflow(WorkflowBusiness.java:176)
at com.dianping.poi.mainflow.core.business.WorkflowBusiness$$FastClassBySpringCGLIB$$f3bb47a4.invoke()
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:736)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:671)
at com.dianping.poi.mainflow.core.business.WorkflowBusiness$$EnhancerBySpringCGLIB$$e721a2aa.createWorkflow()
at com.dianping.poi.mainflow.update.biz.business.MainUpdateFlowBusiness.update(MainUpdateFlowBusiness.java:220)
at com.dianping.poi.mainflow.update.biz.business.MainUpdateFlowBusiness.update(MainUpdateFlowBusiness.java:179)
at com.dianping.poi.mainflow.feedback.biz.serviceImpl.FeedbackForPoiServiceImpl.dpFeedbackBase(FeedbackForPoiServiceImpl.java:1233)
at com.dianping.poi.mainflow.feedback.biz.serviceImpl.FeedbackForPoiServiceImpl.dpTerminalFeedback(FeedbackForPoiServiceImpl.java:486)
at sun.reflect.GeneratedMethodAccessor144.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at com.dianping.pigeon.remoting.provider.service.method.ServiceMethod.invoke(ServiceMethod.java:193)
at com.dianping.pigeon.remoting.provider.process.filter.BusinessProcessFilter.invoke(BusinessProcessFilter.java:79)
at com.dianping.pigeon.remoting.provider.process.filter.BusinessProcessFilter.invoke(BusinessProcessFilter.java:34)
at com.dianping.pigeon.remoting.provider.process.ProviderProcessHandlerFactory$1.handle(ProviderProcessHandlerFactory.java:99)
at com.dianping.pigeon.remoting.provider.process.filter.GatewayProcessFilter.invoke(GatewayProcessFilter.java:242)
at com.dianping.pigeon.remoting.provider.process.filter.GatewayProcessFilter.invoke(GatewayProcessFilter.java:51)
at com.dianping.pigeon.remoting.provider.process.ProviderProcessHandlerFactory$1.handle(ProviderProcessHandlerFactory.java:99)
at com.dianping.pigeon.remoting.provider.process.filter.SecurityFilter.invoke(SecurityFilter.java:31)
at com.dianping.pigeon.remoting.provider.process.filter.SecurityFilter.invoke(SecurityFilter.java:15)
at com.dianping.pigeon.remoting.provider.process.ProviderProcessHandlerFactory$1.handle(ProviderProcessHandlerFactory.java:99)
at com.dianping.pigeon.remoting.provider.process.filter.GenericProcessFilter.invoke(GenericProcessFilter.java:41)
at com.dianping.pigeon.remoting.provider.process.filter.GenericProcessFilter.invoke(GenericProcessFilter.java:24)
at com.dianping.pigeon.remoting.provider.process.ProviderProcessHandlerFactory$1.handle(ProviderProcessHandlerFactory.java:99)
at com.dianping.pigeon.remoting.provider.process.filter.ExceptionProcessFilter.invoke(ExceptionProcessFilter.java:44)
at com.dianping.pigeon.remoting.provider.process.filter.ExceptionProcessFilter.invoke(ExceptionProcessFilter.java:27)
at com.dianping.pigeon.remoting.provider.process.ProviderProcessHandlerFactory$1.handle(ProviderProcessHandlerFactory.java:99)
at com.dianping.pigeon.remoting.provider.process.filter.ContextTransferProcessFilter.invoke(ContextTransferProcessFilter.java:43)
at com.dianping.pigeon.remoting.provider.process.filter.ContextTransferProcessFilter.invoke(ContextTransferProcessFilter.java:28)
at com.dianping.pigeon.remoting.provider.process.ProviderProcessHandlerFactory$1.handle(ProviderProcessHandlerFactory.java:99)
at com.dianping.pigeon.remoting.provider.process.filter.WriteResponseProcessFilter.invoke(WriteResponseProcessFilter.java:36)
at com.dianping.pigeon.remoting.provider.process.filter.WriteResponseProcessFilter.invoke(WriteResponseProcessFilter.java:26)
at com.dianping.pigeon.remoting.provider.process.ProviderProcessHandlerFactory$1.handle(ProviderProcessHandlerFactory.java:99)
at com.dianping.pigeon.remoting.provider.process.filter.TrafficRecordFilter.invoke(TrafficRecordFilter.java:34)
at com.dianping.pigeon.remoting.provider.process.filter.TrafficRecordFilter.invoke(TrafficRecordFilter.java:14)
at com.dianping.pigeon.remoting.provider.process.ProviderProcessHandlerFactory$1.handle(ProviderProcessHandlerFactory.java:99)
at com.dianping.pigeon.remoting.provider.process.filter.InnerTracerFilter.invoke(InnerTracerFilter.java:29)
at com.dianping.pigeon.remoting.provider.process.filter.InnerTracerFilter.invoke(InnerTracerFilter.java:15)
at com.dianping.pigeon.remoting.provider.process.ProviderProcessHandlerFactory$1.handle(ProviderProcessHandlerFactory.java:99)
at com.dianping.pigeon.remoting.provider.process.filter.MonitorProcessFilter.invoke(MonitorProcessFilter.java:101)
at com.dianping.pigeon.remoting.provider.process.filter.MonitorProcessFilter.invoke(MonitorProcessFilter.java:35)
at com.dianping.pigeon.remoting.provider.process.ProviderProcessHandlerFactory$1.handle(ProviderProcessHandlerFactory.java:99)
at com.dianping.pigeon.remoting.provider.process.filter.TracerFilter.invoke(TracerFilter.java:37)
at com.dianping.pigeon.remoting.provider.process.filter.TracerFilter.invoke(TracerFilter.java:15)
at com.dianping.pigeon.remoting.provider.process.ProviderProcessHandlerFactory$1.handle(ProviderProcessHandlerFactory.java:99)
at com.dianping.pigeon.remoting.provider.process.filter.ProviderContextFilter.invoke(ProviderContextFilter.java:28)
at com.dianping.pigeon.remoting.provider.process.filter.ProviderContextFilter.invoke(ProviderContextFilter.java:18)
at com.dianping.pigeon.remoting.provider.process.ProviderProcessHandlerFactory$1.handle(ProviderProcessHandlerFactory.java:99)
at com.dianping.pigeon.remoting.provider.process.threadpool.RequestThreadPoolProcessor$2.call(RequestThreadPoolProcessor.java:254)
at com.dianping.pigeon.remoting.provider.process.threadpool.RequestThreadPoolProcessor$2.call(RequestThreadPoolProcessor.java:243)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Locked ownable synchronizers:

<0x00000007ab2b6228> (a java.util.concurrent.ThreadPoolExecutor$Worker)

Pigeon 阻塞线程 ThreadDump 信息

priority:5 - threadId:0x00007fa599636000 - nativeId:0x2ec8 - nativeId (decimal):11976 - state:BLOCKED
stackTrace:
java.lang.Thread.State: BLOCKED (on object monitor)
at deps.redis.clients.util.RedisInputStream.ensureFill(RedisInputStream.java:207)
at deps.redis.clients.util.RedisInputStream.readByte(RedisInputStream.java:47)
at deps.redis.clients.jedis.Protocol.process(Protocol.java:204)
at deps.redis.clients.jedis.Protocol.read(Protocol.java:271)
at deps.redis.clients.jedis.Connection.readProtocolWithCheckingBroken(Connection.java:305)
at deps.redis.clients.jedis.Connection.getBinaryBulkReply(Connection.java:236)
at deps.redis.clients.jedis.BinaryJedis.hget(BinaryJedis.java:788)
at deps.redis.clients.jedis.BinaryJedisCluster$13.execute(BinaryJedisCluster.java:202)
at deps.redis.clients.jedis.BinaryJedisCluster$13.execute(BinaryJedisCluster.java:199)
at deps.redis.clients.jedis.JedisClusterCommand.runWithRetries(JedisClusterCommand.java:64)
at deps.redis.clients.jedis.JedisClusterCommand.runBinary(JedisClusterCommand.java:41)
at deps.redis.clients.jedis.BinaryJedisCluster.hget(BinaryJedisCluster.java:199)
at com.dianping.squirrel.client.impl.redis.RedisStoreClientImpl$41.excute(RedisStoreClientImpl.java:1022)
at com.dianping.squirrel.client.impl.AbstractStoreClient$MonitorCommand.run(AbstractStoreClient.java:1066)
at com.dianping.squirrel.client.impl.redis.RedisStoreClientImpl.hget(RedisStoreClientImpl.java:1018)
at com.dianping.poi.mainflow.core.redisdao.TimestampRedisDao.getUpdateTime(TimestampRedisDao.java:18)
at com.dianping.poi.mainflow.common.RefreshableCache.checkUpdate(RefreshableCache.java:99)

locked <0x00000007623197a0> (a com.dianping.poi.mainflow.core.cache.FlowTemplateRuleCache)

com.dianping.poi.mainflow.common.RefreshableCache.getValue(RefreshableCache.java:53)

at com.dianping.poi.mainflow.common.RefreshableCache.getValue(RefreshableCache.java:43)
at com.dianping.poi.mainflow.core.business.WorkflowBusiness.getTemplateRule(WorkflowBusiness.java:160)
at com.dianping.poi.mainflow.core.business.WorkflowBusiness.setTemplateByWorkflow(WorkflowBusiness.java:134)
at com.dianping.poi.mainflow.core.business.WorkflowBusiness.createWorkflow(WorkflowBusiness.java:253)
at com.dianping.poi.mainflow.core.business.WorkflowBusiness.createWorkflow(WorkflowBusiness.java:183)
at com.dianping.poi.mainflow.core.business.WorkflowBusiness.createWorkflow(WorkflowBusiness.java:176)
at com.dianping.poi.mainflow.core.business.WorkflowBusiness$$FastClassBySpringCGLIB$$f3bb47a4.invoke()
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:736)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:671)
at com.dianping.poi.mainflow.core.business.WorkflowBusiness$$EnhancerBySpringCGLIB$$e721a2aa.createWorkflow()
at com.dianping.poi.mainflow.update.biz.business.MainUpdateFlowBusiness.update(MainUpdateFlowBusiness.java:220)
at com.dianping.poi.mainflow.update.biz.business.MainUpdateFlowBusiness.update(MainUpdateFlowBusiness.java:179)
at com.dianping.poi.mainflow.feedback.biz.serviceImpl.FeedbackForPoiServiceImpl.dpFeedbackBase(FeedbackForPoiServiceImpl.java:1233)
at com.dianping.poi.mainflow.feedback.biz.serviceImpl.FeedbackForPoiServiceImpl.dpTerminalFeedback(FeedbackForPoiServiceImpl.java:486)
at sun.reflect.GeneratedMethodAccessor144.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at com.dianping.pigeon.remoting.provider.service.method.ServiceMethod.invoke(ServiceMethod.java:193)
at com.dianping.pigeon.remoting.provider.process.filter.BusinessProcessFilter.invoke(BusinessProcessFilter.java:79)
at com.dianping.pigeon.remoting.provider.process.filter.BusinessProcessFilter.invoke(BusinessProcessFilter.java:34)
at com.dianping.pigeon.remoting.provider.process.ProviderProcessHandlerFactory$1.handle(ProviderProcessHandlerFactory.java:99)
at com.dianping.pigeon.remoting.provider.process.filter.GatewayProcessFilter.invoke(GatewayProcessFilter.java:242)
at com.dianping.pigeon.remoting.provider.process.filter.GatewayProcessFilter.invoke(GatewayProcessFilter.java:51)
at com.dianping.pigeon.remoting.provider.process.ProviderProcessHandlerFactory$1.handle(ProviderProcessHandlerFactory.java:99)
at com.dianping.pigeon.remoting.provider.process.filter.SecurityFilter.invoke(SecurityFilter.java:31)
at com.dianping.pigeon.remoting.provider.process.filter.SecurityFilter.invoke(SecurityFilter.java:15)
at com.dianping.pigeon.remoting.provider.process.ProviderProcessHandlerFactory$1.handle(ProviderProcessHandlerFactory.java:99)
at com.dianping.pigeon.remoting.provider.process.filter.GenericProcessFilter.invoke(GenericProcessFilter.java:41)
at com.dianping.pigeon.remoting.provider.process.filter.GenericProcessFilter.invoke(GenericProcessFilter.java:24)
at com.dianping.pigeon.remoting.provider.process.ProviderProcessHandlerFactory$1.handle(ProviderProcessHandlerFactory.java:99)
at com.dianping.pigeon.remoting.provider.process.filter.ExceptionProcessFilter.invoke(ExceptionProcessFilter.java:44)
at com.dianping.pigeon.remoting.provider.process.filter.ExceptionProcessFilter.invoke(ExceptionProcessFilter.java:27)
at com.dianping.pigeon.remoting.provider.process.ProviderProcessHandlerFactory$1.handle(ProviderProcessHandlerFactory.java:99)
at com.dianping.pigeon.remoting.provider.process.filter.ContextTransferProcessFilter.invoke(ContextTransferProcessFilter.java:43)
at com.dianping.pigeon.remoting.provider.process.filter.ContextTransferProcessFilter.invoke(ContextTransferProcessFilter.java:28)
at com.dianping.pigeon.remoting.provider.process.ProviderProcessHandlerFactory$1.handle(ProviderProcessHandlerFactory.java:99)
at com.dianping.pigeon.remoting.provider.process.filter.WriteResponseProcessFilter.invoke(WriteResponseProcessFilter.java:36)
at com.dianping.pigeon.remoting.provider.process.filter.WriteResponseProcessFilter.invoke(WriteResponseProcessFilter.java:26)
at com.dianping.pigeon.remoting.provider.process.ProviderProcessHandlerFactory$1.handle(ProviderProcessHandlerFactory.java:99)
at com.dianping.pigeon.remoting.provider.process.filter.TrafficRecordFilter.invoke(TrafficRecordFilter.java:34)
at com.dianping.pigeon.remoting.provider.process.filter.TrafficRecordFilter.invoke(TrafficRecordFilter.java:14)
at com.dianping.pigeon.remoting.provider.process.ProviderProcessHandlerFactory$1.handle(ProviderProcessHandlerFactory.java:99)
at com.dianping.pigeon.remoting.provider.process.filter.InnerTracerFilter.invoke(InnerTracerFilter.java:29)
at com.dianping.pigeon.remoting.provider.process.filter.InnerTracerFilter.invoke(InnerTracerFilter.java:15)
at com.dianping.pigeon.remoting.provider.process.ProviderProcessHandlerFactory$1.handle(ProviderProcessHandlerFactory.java:99)
at com.dianping.pigeon.remoting.provider.process.filter.MonitorProcessFilter.invoke(MonitorProcessFilter.java:101)
at com.dianping.pigeon.remoting.provider.process.filter.MonitorProcessFilter.invoke(MonitorProcessFilter.java:35)
at com.dianping.pigeon.remoting.provider.process.ProviderProcessHandlerFactory$1.handle(ProviderProcessHandlerFactory.java:99)
at com.dianping.pigeon.remoting.provider.process.filter.TracerFilter.invoke(TracerFilter.java:37)
at com.dianping.pigeon.remoting.provider.process.filter.TracerFilter.invoke(TracerFilter.java:15)
at com.dianping.pigeon.remoting.provider.process.ProviderProcessHandlerFactory$1.handle(ProviderProcessHandlerFactory.java:99)
at com.dianping.pigeon.remoting.provider.process.filter.ProviderContextFilter.invoke(ProviderContextFilter.java:28)
at com.dianping.pigeon.remoting.provider.process.filter.ProviderContextFilter.invoke(ProviderContextFilter.java:18)
at com.dianping.pigeon.remoting.provider.process.ProviderProcessHandlerFactory$1.handle(ProviderProcessHandlerFactory.java:99)
at com.dianping.pigeon.remoting.provider.process.threadpool.RequestThreadPoolProcessor$2.call(RequestThreadPoolProcessor.java:254)
at com.dianping.pigeon.remoting.provider.process.threadpool.RequestThreadPoolProcessor$2.call(RequestThreadPoolProcessor.java:243)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Locked ownable synchronizers:
- <0x0000000735ab3bc0> (a java.util.concurrent.ThreadPoolExecutor$Worker)

问题说明

通过对应用系统的模拟上线应用运行状态分析，目标找出系统的瓶颈点，以及通过对应用系统的资源使用情况来评估应用系统的相关参数设置是否合理；
如何根据应用系统的运行时的性能监控，动态的评估应用系统潜在的瓶颈点，以及预测此瓶颈点对应用的影响，是否可以动态的调配相关应用参数，来自适用应用系统性能，充分利用应用系统资源(CPU,Memory,IO)等，结合应用系统的任务使用特性(CPU 密集型，IO 密集型，MiX 混合性）以及多个线程池任务执行特性，是否能够动态预测。

Arthas 征文活动火热进行中

Arthas 官方正在举行征文活动，如果你有：

使用 Arthas 排查过的问题
对 Arthas 进行源码解读
对 Arthas 提出建议
不限，其它与 Arthas 有关的内容

欢迎参加征文活动，还有奖品拿哦~点击投稿

“阿里巴巴云原生关注微服务、Serverless、容器、Service Mesh 等技术领域、聚焦云原生流行技术趋势、云原生大规模的落地实践，做最懂云原生开发者的公众号。”

微信关注我们

原文链接：https://yq.aliyun.com/articles/771475

转载内容版权归作者及来源网站所有！

低调大师中文资讯倾力打造互联网数据资讯、行业资源、电子商务、移动互联网、网络营销平台。持续更新报道IT业界、互联网、市场资讯、驱动更新,是最及时权威的产业资讯及硬件资讯报道平台。

java安全编码指南之:Mutability可变性

简介 mutable（可变）和immutable（不可变）对象是我们在java程序编写的过程中经常会使用到的。可变类型对象就是说，对象在创建之后，其内部的数据可能会被修改。所以它的安全性没有保证。而不可变类型对象就是说，对象一旦创建之后，其内部的数据就不能够被修改，我们可以完全相信这个对象。虽然mutable对象安全性不够，但是因为其可以被修改，所以会有效的减少对该对象的拷贝。而immutable对象因为不可改变，所以尝试对该对象的修改都会导致对象的拷贝，从而生成新的对象。我们最常使用的String就是一个immutable对象。那么可变性在java的安全编码中的最佳实践是怎么样的呢？一起来看看吧。可变对象和不可变对象知道了可变对象和不可变对象的不同之处之后，我们看一下怎么才能判断这个对象是可变对象还是不可变对象呢？首先，最简单的一点就是，不可变对象创建之后就不能够被修改，所以不可变对象里面基本上没有setXXX之类的方法，而可变对象提供了setXXX这些可以修改内部变量状态的方法。看一个例子java.util.Date是一个可变对象，而java.time.Loc...

2020-09-03

483

前言在日常生活中，我们时常会接收到一些垃圾短信和邮件，造成这种原因就是因为我们使用自己的手机号码在App上注册了账号，导致手机号泄露，成为了别人发财的工具。一、如何避免接收垃圾短信众所周知，针对短信和邮箱都有相应的屏蔽号码或者是邮箱号的设置，但是并不是很智能。因为我们永远不知道下一秒钟究竟会是哪个大佬来光顾我们。一个一个去设置显得太麻烦，这里给大家介绍两个平台，超级好用。既不用担心泄露手机号码，也不会再接收到垃圾短信和邮件了。 Top 1.云短信神器地址： https://www.materialtools.com/?page=1 它可以代替你的手机号进行注册，并且也会和接收到验证码，你只需要把上面能用的手机号输入到你想注册的app里面，然后发送验证就可以了。不过，它有一个缺陷就是我们用的手机号接收的验证码它会显示在这上面，基本所有用这个神器的人都能看到，就给人一种毫无隐私可言的感觉。不过为了能不接收垃圾短信，也无妨，毕竟问题不大。可以看到这是最近一段时间申请注册的平台名和时间。这里可以看到已经有这么多人使用了，可见这个神器还是挺受欢迎的。有了这款神奇妈妈再也不用担心我...

2020-09-03

713

资源下载

更多资源

优质分享App

近一个月的开发和优化，本站点的第一个app全新上线。该app采用极致压缩，本体才4.36MB。系统里面做了大量数据访问、缓存优化。方便用户在手机上查看文章。后续会推出HarmonyOS的适配版本。

Mario

马里奥是站在游戏界顶峰的超人气多面角色。马里奥靠吃蘑菇成长，特征是大鼻子、头戴帽子、身穿背带裤，还留着胡子。与他的双胞胎兄弟路易基一起，长年担任任天堂的招牌角色。

Nacos

Nacos /nɑ:kəʊs/ 是 Dynamic Naming and Configuration Service 的首字母简称，一个易于构建 AI Agent 应用的动态服务发现、配置管理和AI智能体管理平台。Nacos 致力于帮助您发现、配置和管理微服务及AI智能体应用。Nacos 提供了一组简单易用的特性集，帮助您快速实现动态服务发现、服务配置、服务元数据、流量管理。Nacos 帮助您更敏捷和容易地构建、交付和管理微服务平台。

Spring

Spring框架（Spring Framework）是由Rod Johnson于2002年提出的开源Java企业级应用框架，旨在通过使用JavaBean替代传统EJB实现方式降低企业级编程开发的复杂性。该框架基于简单性、可测试性和松耦合性设计理念，提供核心容器、应用上下文、数据访问集成等模块，支持整合Hibernate、Struts等第三方框架，其适用范围不仅限于服务器端开发，绝大多数Java应用均可从中受益。