java项目内存使用率过高排查_项目内存或者 cpu 占用率过高如何排查

前言:小编总结了之前生产环境cpu 占用率过高等问题,小编功力不够深厚,文章如有不对的地方,还望各位大神指正。

排查原因：客服反馈说系统访问缓慢

一、在排查问题的过程中针对 CPU 的问题，使用以下命令组合来排查问题

模拟过程:

①示例代码：

package com.sunxxx.task;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import org.springframework.scheduling.annotation.EnableScheduling;

import org.springframework.scheduling.annotation.Scheduled;

import org.springframework.stereotype.Component;

@Component

@EnableScheduling

public class JobTask {

Logger logger = LoggerFactory.getLogger(JobTask.class);

@Scheduled(cron = "0 0/2 * * * *")

public void task(){

try {

logger.info(Thread.currentThread().getName()+"开始执行业务代码");

Integer sum = 0;

Thread.sleep(30000);

for (; ; ) {//死循环,模拟出CPU100%

}

// logger.info(Thread.currentThread().getName()+"执行任务结束:"+sum);

} catch (InterruptedException e) {

e.printStackTrace();

}

②将项目打包,打包命令:

mvn clean package -Dmaven.test.skip=true

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打包成功.png

③放到服务器上执行

java -jar xxx.jar

排查过程：

**① **查看问题进程，得到进程 PID：

top -c

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top -c.png

②查看进程里的线程明细，并手动记下 CPU 异常的线程 PID：

top -p PID -H

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top -p PID -H.png

③ 使用 jdk 提供 jstack 命令打印出项目堆栈：

jstack 3464 >3464.log

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jstack.png

项目后台打印出来的日志:

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项目后台日志.png

jatask命令得到的线程快照:

2020-03-21 13:06:17

Full thread dump Java HotSpot(TM) 64-Bit Server VM (25.151-b12 mixed mode):

"DestroyJavaVM" #31 prio=5 os_prio=0 tid=0x00007f8828008800 nid=0xd76 waiting on condition [0x0000000000000000]

java.lang.Thread.State: RUNNABLE

"http-nio-8089-Acceptor-0" #29 daemon prio=5 os_prio=0 tid=0x00007f88281ef000 nid=0xd96 runnable [0x00007f87ce3a9000]

java.lang.Thread.State: RUNNABLE

at sun.nio.ch.ServerSocketChannelImpl.accept0(Native Method)

at sun.nio.ch.ServerSocketChannelImpl.accept(ServerSocketChannelImpl.java:422)

at sun.nio.ch.ServerSocketChannelImpl.accept(ServerSocketChannelImpl.java:250)

- locked <0x00000000fcc0f6e8> (a java.lang.Object)

at org.apache.tomcat.util.net.NioEndpoint.serverSocketAccept(NioEndpoint.java:448)

at org.apache.tomcat.util.net.NioEndpoint.serverSocketAccept(NioEndpoint.java:70)

at org.apache.tomcat.util.net.Acceptor.run(Acceptor.java:95)

at java.lang.Thread.run(Thread.java:748)

"http-nio-8089-ClientPoller-1" #28 daemon prio=5 os_prio=0 tid=0x00007f8829052800 nid=0xd95 runnable [0x00007f87ce4aa000]

java.lang.Thread.State: RUNNABLE

at sun.nio.ch.EPollArrayWrapper.epollWait(Native Method)

at sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:269)

at sun.nio.ch.EPollSelectorImpl.doSelect(EPollSelectorImpl.java:93)

at sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:86)

- locked <0x00000000fcdd1ed0> (a sun.nio.ch.Util$3)

- locked <0x00000000fcdd1ec0> (a java.util.Collections$UnmodifiableSet)

- locked <0x00000000fcdd1da8> (a sun.nio.ch.EPollSelectorImpl)

at sun.nio.ch.SelectorImpl.select(SelectorImpl.java:97)

at org.apache.tomcat.util.net.NioEndpoint$Poller.run(NioEndpoint.java:744)

at java.lang.Thread.run(Thread.java:748)

"http-nio-8089-ClientPoller-0" #27 daemon prio=5 os_prio=0 tid=0x00007f8829598800 nid=0xd94 runnable [0x00007f87ce5ab000]

java.lang.Thread.State: RUNNABLE

at sun.nio.ch.EPollArrayWrapper.epollWait(Native Method)

at sun.nio.ch.EPollArrayWrapper.poll(EPollArrayWrapper.java:269)

at sun.nio.ch.EPollSelectorImpl.doSelect(EPollSelectorImpl.java:93)

at sun.nio.ch.SelectorImpl.lockAndDoSelect(SelectorImpl.java:86)

- locked <0x00000000fcdd0540> (a sun.nio.ch.Util$3)

- locked <0x00000000fcdd0530> (a java.util.Collections$UnmodifiableSet)

- locked <0x00000000fcdd0418> (a sun.nio.ch.EPollSelectorImpl)

at sun.nio.ch.SelectorImpl.select(SelectorImpl.java:97)

at org.apache.tomcat.util.net.NioEndpoint$Poller.run(NioEndpoint.java:744)

at java.lang.Thread.run(Thread.java:748)

"http-nio-8089-exec-10" #26 daemon prio=5 os_prio=0 tid=0x00007f8829594800 nid=0xd93 waiting on condition [0x00007f87ce8ac000]

java.lang.Thread.State: WAITING (parking)

at sun.misc.Unsafe.park(Native Method)

- parking to wait for <0x00000000fcc5daf0> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)

at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)

at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)

at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442)

at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:103)

at org.apache.tomcat.util.threads.TaskQueue.take(TaskQueue.java:31)

at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1074)

at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1134)

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)

"http-nio-8089-exec-9" #25 daemon prio=5 os_prio=0 tid=0x00007f8829592800 nid=0xd92 waiting on condition [0x00007f87ce9ad000]