9. 工具包
1. JVM自带工具
1.1. jps
1.2. jstack
1.3. jmap
1.4. jcmd
1.5. jinfo
1.6. jprofiler
1.7. jvisualvm
jcmd jmap jinfo pid // jstack pid // 查看当前jvm有哪些进程，初步排查线程健康状况，如果多数线程处于等待状态，很可能就有问题了 jstat -gc pid // GC回收情况 jps -l
./ch09-tools/image/1680448811163.png
- 把堆内存dump下载./ch09-tools/image/1680448938831.png jps //查看pid jmap -dump:format=b,file=heap.1 pid //不进行垃圾回收直接dump jmap -dump:live,format=b,file=heap.2 pid //进行fgc垃圾回收在进行dump jmap -histo:live pid //进行fgc垃圾回收在进行dump
- 使用java VisualVM(lib目录下jdk8自带)导入dump文件
2. 第三方工具
- Arhtas
- 通过 Arthas Trace 命令将接口性能优化十倍（User Case 投稿）
- 动态追踪技术漫谈
- 利用Arthas精准定位Java应用CPU负载过高问题
- 阿里Java诊断工具 arthas - 排查线上环境内存使用过大、线程cpu使用率高问题
- 【死磕JVM】用Arthas排查JVM内存 真爽！我从小用到大
3. 安装
4. 启动
java -jar arthas-boot.jar
5. 常用命令
- dashboard
- thread -b
- jvm
- heapdum /path/to/hproffile/my.hprof
6. 常用场景
- 查看jvm参数
- 查看阻塞的线程
- 生成堆栈快照文件
- 查看仪表盘
- 查看类加载信息
- 在线更换.class文件
- 项目启动时，查看各个区域所使用的比例，来判断各个参数的配置应该是多少
7. 控制面板
发送请求，发现 『ps_old_gen』 区域的使用容量越来越大，如下面两张图，这说明有很多大对象进入了老年代。
./ch09-tools/image/1680439140349.png 
./ch09-tools/image/1680439220617.png
8. 利用Arthas生成dump文件
9. Arthas的其他命./ch09-tools/image/1680439460507.png
- 运行
- 选取一个应用进行链接 ./ch09-tools/image/1680441120803.png
- 查看仪表盘 ./ch09-tools/image/1680441169809.png
[arthas@41713]$ dashboard
[arthas@47132]$ jvm
RUNTIME
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
MACHINE-NAME 47132@ShawndeMacBook-Pro.local
JVM-START-TIME 2023-04-02 21:28:43
MANAGEMENT-SPEC-VERSION 1.2
SPEC-NAME Java Virtual Machine Specification
SPEC-VENDOR Oracle Corporation
SPEC-VERSION 1.8
VM-NAME OpenJDK 64-Bit Server VM
VM-VENDOR Azul Systems, Inc.
VM-VERSION 25.282-b08
INPUT-ARGUMENTS -Xms100m
-Xmx100m
-verbose:gc
-XX:+PrintGCDetails
-XX:+PrintGCDateStamps
-XX:+HeapDumpOnOutOfMemoryError
-XX:HeapDumpPath=/Users/shawnwang/Downloads/jvm-logs
-XX:ErrorFile=/Users/shawnwang/Downloads/jvm-logs/java_err.log
-Xloggc:/Users/shawnwang/Downloads/jvm-logs/gc.log
CLASS-PATH jvm-test-0.0.1-SNAPSHOT.jar
BOOT-CLASS-PATH /Library/Java/JavaVirtualMachines/zulu-8.jdk/Contents/Home/jre/lib/resources.jar:/Library/Java/JavaVirtualMachines/zulu-8.jdk/Contents/Home/jre/lib/rt.jar:/Library/Java/Jav
aVirtualMachines/zulu-8.jdk/Contents/Home/jre/lib/sunrsasign.jar:/Library/Java/JavaVirtualMachines/zulu-8.jdk/Contents/Home/jre/lib/jsse.jar:/Library/Java/JavaVirtualMachin
es/zulu-8.jdk/Contents/Home/jre/lib/jce.jar:/Library/Java/JavaVirtualMachines/zulu-8.jdk/Contents/Home/jre/lib/charsets.jar:/Library/Java/JavaVirtualMachines/zulu-8.jdk/Con
tents/Home/jre/lib/jfr.jar:/Library/Java/JavaVirtualMachines/zulu-8.jdk/Contents/Home/jre/classes
LIBRARY-PATH /Users/shawnwang/Library/Java/Extensions:/Library/Java/Extensions:/Network/Library/Java/Extensions:/System/Library/Java/Extensions:/usr/lib/java:.
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
CLASS-LOADING
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
LOADED-CLASS-COUNT 8164
TOTAL-LOADED-CLASS-COUNT 8164
UNLOADED-CLASS-COUNT 0
IS-VERBOSE false
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
COMPILATION
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
NAME HotSpot 64-Bit Tiered Compilers
TOTAL-COMPILE-TIME 3537
[time (ms)]
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
GARBAGE-COLLECTORS
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
PS Scavenge name : PS Scavenge
[count/time (ms)] collectionCount : 16
collectionTime : 36
PS MarkSweep name : PS MarkSweep
[count/time (ms)] collectionCount : 2
collectionTime : 61
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
MEMORY-MANAGERS
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
CodeCacheManager Code Cache
Metaspace Manager Metaspace
Compressed Class Space
PS Scavenge PS Eden Space
PS Survivor Space
PS MarkSweep PS Eden Space
PS Survivor Space
PS Old Gen
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
MEMORY
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
HEAP-MEMORY-USAGE init : 109051904(104.0 MiB)
[memory in bytes] used : 33169048(31.6 MiB)
committed : 95420416(91.0 MiB)
max : 96993280(92.5 MiB)
NO-HEAP-MEMORY-USAGE init : 2555904(2.4 MiB)
[memory in bytes] used : 59594664(56.8 MiB)
committed : 63012864(60.1 MiB)
max : -1(-1 B)
PENDING-FINALIZE-COUNT 0
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
OPERATING-SYSTEM
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
OS Mac OS X
ARCH aarch64
PROCESSORS-COUNT 8
LOAD-AVERAGE 2.14892578125
VERSION 13.0.1
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
THREAD
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
COUNT 30
DAEMON-COUNT 26
PEAK-COUNT 30
STARTED-COUNT 35
DEADLOCK-COUNT 0
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
FILE-DESCRIPTOR
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
MAX-FILE-DESCRIPTOR-COUNT 10240
OPEN-FILE-DESCRIPTOR-COUNT 202java -server -Xms100m -Xmx100m -verbose:gc -XX:+PrintGCDetails \
-XX:+PrintGCDateStamps \
-XX:+HeapDumpOnOutOfMemoryError \
-XX:HeapDumpPath=/Users/shawnwang/Downloads/jvm-logs \
-XX:ErrorFile=/Users/shawnwang/Downloads/jvm-logs/java_err.log \
-XX:+UseG1GC -XX:SoftRefLRUPolicyMSPerMB=0 -XX:SurvivorRatio=8 \
-Xloggc:/Users/shawnwang/Downloads/jvm-logs/gc.log \
-jar jvm-test-0.0.1-SNAPSHOT.jar
[arthas@46428]$ jvm
RUNTIME
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
MACHINE-NAME 46428@ShawndeMacBook-Pro.local
JVM-START-TIME 2023-04-02 21:19:08
MANAGEMENT-SPEC-VERSION 1.2
SPEC-NAME Java Virtual Machine Specification
SPEC-VENDOR Oracle Corporation
SPEC-VERSION 1.8
VM-NAME OpenJDK 64-Bit Server VM
VM-VENDOR Azul Systems, Inc.
VM-VERSION 25.282-b08
INPUT-ARGUMENTS -Xms100m
-Xmx100m
-verbose:gc
-XX:+PrintGCDetails
-XX:+PrintGCDateStamps
-XX:+HeapDumpOnOutOfMemoryError
-XX:HeapDumpPath=/Users/shawnwang/Downloads/jvm-logs
-XX:ErrorFile=/Users/shawnwang/Downloads/jvm-logs/java_err.log
-XX:+UseG1GC
-XX:SoftRefLRUPolicyMSPerMB=0
-XX:SurvivorRatio=8
-Xloggc:/Users/shawnwang/Downloads/jvm-logs/gc.log
CLASS-PATH jvm-test-0.0.1-SNAPSHOT.jar
BOOT-CLASS-PATH /Library/Java/JavaVirtualMachines/zulu-8.jdk/Contents/Home/jre/lib/resources.jar:/Library/Java/JavaVirtualMachines/zulu-8.jdk/Contents/Home/jre/lib/rt.jar:/Library/Java/Jav
aVirtualMachines/zulu-8.jdk/Contents/Home/jre/lib/sunrsasign.jar:/Library/Java/JavaVirtualMachines/zulu-8.jdk/Contents/Home/jre/lib/jsse.jar:/Library/Java/JavaVirtualMachin
es/zulu-8.jdk/Contents/Home/jre/lib/jce.jar:/Library/Java/JavaVirtualMachines/zulu-8.jdk/Contents/Home/jre/lib/charsets.jar:/Library/Java/JavaVirtualMachines/zulu-8.jdk/Con
tents/Home/jre/lib/jfr.jar:/Library/Java/JavaVirtualMachines/zulu-8.jdk/Contents/Home/jre/classes
LIBRARY-PATH /Users/shawnwang/Library/Java/Extensions:/Library/Java/Extensions:/Network/Library/Java/Extensions:/System/Library/Java/Extensions:/usr/lib/java:.
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
CLASS-LOADING
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
LOADED-CLASS-COUNT 8783
TOTAL-LOADED-CLASS-COUNT 8791
UNLOADED-CLASS-COUNT 8
IS-VERBOSE false
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
COMPILATION
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
NAME HotSpot 64-Bit Tiered Compilers
TOTAL-COMPILE-TIME 5532
[time (ms)]
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
GARBAGE-COLLECTORS
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
G1 Young Generation name : G1 Young Generation
[count/time (ms)] collectionCount : 8
collectionTime : 50
G1 Old Generation name : G1 Old Generation
[count/time (ms)] collectionCount : 0
collectionTime : 0
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
MEMORY-MANAGERS
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
CodeCacheManager Code Cache
Metaspace Manager Metaspace
Compressed Class Space
G1 Young Generation G1 Eden Space
G1 Survivor Space
G1 Old Gen
G1 Old Generation G1 Eden Space
G1 Survivor Space
G1 Old Gen
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
MEMORY
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
HEAP-MEMORY-USAGE init : 109051904(104.0 MiB)
[memory in bytes] used : 55500944(52.9 MiB)
committed : 109051904(104.0 MiB)
max : 109051904(104.0 MiB)
NO-HEAP-MEMORY-USAGE init : 2555904(2.4 MiB)
[memory in bytes] used : 68178360(65.0 MiB)
committed : 71303168(68.0 MiB)
max : -1(-1 B)
PENDING-FINALIZE-COUNT 0
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
OPERATING-SYSTEM
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
OS Mac OS X
ARCH aarch64
PROCESSORS-COUNT 8
LOAD-AVERAGE 1.33984375
VERSION 13.0.1
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
THREAD
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
COUNT 45
DAEMON-COUNT 41
PEAK-COUNT 46
STARTED-COUNT 53
DEADLOCK-COUNT 0
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
FILE-DESCRIPTOR
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
MAX-FILE-DESCRIPTOR-COUNT 10240
OPEN-FILE-DESCRIPTOR-COUNT 202$ thread -b
"http-bio-8080-exec-4" Id=27 TIMED_WAITING
at java.lang.Thread.sleep(Native Method)
at test.arthas.TestThreadBlocking.doGet(TestThreadBlocking.java:22)
- locked java.lang.Object@725be470 <---- but blocks 4 other threads!
at javax.servlet.http.HttpServlet.service(HttpServlet.java:624)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at test.filter.TestDurexFilter.doFilter(TestDurexFilter.java:46)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
at com.taobao.tomcat.valves.ContextLoadFilterValve$FilterChainAdapter.doFilter(ContextLoadFilterValve.java:191)
at com.taobao.eagleeye.EagleEyeFilter.doFilter(EagleEyeFilter.java:81)
at com.taobao.tomcat.valves.ContextLoadFilterValve.invoke(ContextLoadFilterValve.java:150)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:429)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1085)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
- locked org.apache.tomcat.util.net.SocketWrapper@7127ee12
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
Number of locked synchronizers = 1
- java.util.concurrent.ThreadPoolExecutor$Worker@31a6493e10. Arthas场景应用
- 获取jvm启动时所设置的参数
- 监控thread的运行情况
- 监控内存的运行情况
- 生成dump文件
- 动态替换.class文件，达到不停机式投产