java性能火焰圖的生成實踐

更新時間：2025年07月10日 16:13:13 作者：運維打怪晉級之路

文章介紹async-profiler這一Java性能分析工具,可低開銷生成火焰圖,幫助定位CPU飆升、內(nèi)存泄露等問題,涵蓋準(zhǔn)備程序、生成數(shù)據(jù)及展示三個核心步驟,適合解決線上性能瓶頸

序言

如果你經(jīng)常遇到 Java 線上性能問題束手無策，看著線上服務(wù) CPU 飆升一籌莫展，發(fā)現(xiàn)內(nèi)存不斷泄露滿臉茫然。

別慌，這里有一款低開銷、自帶火焰圖、讓你大呼好用的 Java 性能分析工具 - async-profiler。

1、準(zhǔn)備程序

[root@localhost ~]# git clone git://github.com/jvm-profiling-tools/async-profiler
[root@localhost async-profiler]# yum -y install gcc+ gcc-c++
[root@localhost async-profiler]# make 
[root@localhost ~]# more  Test.java  
public class Test {

    public static void main(String[] args) throws Exception {
        Test test = new Test();
        while (true) {
            test.func1();
            test.func2();
            test.func3();
        }
    }

    public void func1() throws Exception { //調(diào)用第一個方法，需要100ms
        Thread.sleep(100L);
    }

    public void func2() throws Exception { //調(diào)用第二個方法，需要500ms
        Thread.sleep(500L);
    }

    public void func3() throws Exception { //調(diào)用第三個方法，需要1500ms
        Thread.sleep(1500L);
    }

}
[root@localhost ~]# 
[root@localhost ~]#  javac Test.java 
[root@localhost ~]# java Test

生成火焰圖數(shù)據(jù)

root      21765   7152  0 18:29 pts/1    00:00:00 java Test
root      21799  21777  0 18:29 pts/0    00:00:00 grep --color=auto java
[root@localhost ~]# cd async-profiler/
[root@localhost async-profiler]# 
[root@localhost async-profiler]# ./profiler.sh -d 60 -o collapsed -f /tmp/test_01.txt  21765
Profiling for 60 seconds
Done
[root@localhost async-profiler]# cd ..
[root@localhost ~]# ls
anaconda-ks.cfg  a.out  async-profiler  FlameGraph  jdk-8u121-linux-x64.tar.gz  perf.data  process.svg  test.c  Test.class  Test.java
[root@localhost ~]# cd  FlameGraph/
[root@localhost FlameGraph]# perl flamegraph.pl --colors=java /tmp/test_01.txt > test_01.svg
[root@localhost FlameGraph]# ls
aix-perf.pl                example-perf-stacks.txt.gz  README.md                  stackcollapse-instruments.pl      stackcollapse-pmc.pl        test
demos                      example-perf.svg            record-test.sh             stackcollapse-java-exceptions.pl  stackcollapse-recursive.pl  test_01.svg
dev                        files.pl                    stackcollapse-aix.pl       stackcollapse-jstack.pl           stackcollapse-sample.awk    test.sh
difffolded.pl              flamegraph.pl               stackcollapse-bpftrace.pl  stackcollapse-ljp.awk             stackcollapse-stap.pl
docs                       jmaps                       stackcollapse-elfutils.pl  stackcollapse-perf.pl             stackcollapse-vsprof.pl
example-dtrace-stacks.txt  pkgsplit-perf.pl            stackcollapse-gdb.pl       stackcollapse-perf-sched.awk      stackcollapse-vtune.pl
example-dtrace.svg         range-perf.pl               stackcollapse-go.pl        stackcollapse.pl                  stackcollapse-xdebug.php
[root@localhost FlameGraph]# sz test_01.svg