測試代碼

import java.math.BigDecimal; import java.util.ArrayList; import java.util.Date; import java.util.List; import java.util.concurrent.ScheduledThreadPoolExecutor; import java.util.concurrent.ThreadPoolExecutor; import java.util.concurrent.TimeUnit;/*** 從數(shù)據(jù)庫中讀取信用數(shù)據(jù)，套用模型，并把結(jié)果進(jìn)行記錄和傳輸*/public class T15_FullGC_Problem01 {private static class CardInfo {BigDecimal price = new BigDecimal(0.0);String name = "張三";int age = 5;Date birthdate = new Date();public void m() {}}private static ScheduledThreadPoolExecutor executor = new ScheduledThreadPoolExecutor(50,new ThreadPoolExecutor.DiscardOldestPolicy());public static void main(String[] args) throws Exception {executor.setMaximumPoolSize(50);for (;;){modelFit();Thread.sleep(100);}}private static void modelFit(){List<CardInfo> taskList = getAllCardInfo();taskList.forEach(info -> {// do somethingexecutor.scheduleWithFixedDelay(() -> {//do sth with infoinfo.m();}, 2, 3, TimeUnit.SECONDS);});}private static List<CardInfo> getAllCardInfo(){List<CardInfo> taskList = new ArrayList<>();for (int i = 0; i < 100; i++) {CardInfo ci = new CardInfo();taskList.add(ci);}return taskList;} }

java -Xms200M -Xmx200M com.mashibing.jvm.gc.T15_FullGC_Problem01

top命令觀察到問題：內(nèi)存不斷增長 CPU占用率居高不下

jps定位具體java進(jìn)程

jinfo pid

jstat -gc 動態(tài)觀察gc情況 / 閱讀GC日志發(fā)現(xiàn)頻繁GC / arthas觀察 / jconsole jstat -gc 4655 500 : 每個500個毫秒打印GC的情況

jmap - histo 4655 | head -20，查找有多少對象產(chǎn)生

jmap -dump:format=b,file=xxx pid / jmap -histo

java -Xms20M -Xmx20M -XX:+UseParallelGC -XX:+HeapDumpOnOutOfMemoryError com.mashibing.jvm.gc.T15_FullGC_Problem01

使用MAT / jhat進(jìn)行dump文件分析 https://www.cnblogs.com/baihuitestsoftware/articles/6406271.html

找到代碼的問題

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