系列
- Arthas入门篇
- Arthas功能介绍
- Arthas 启动过程分析
- Arthas使用Idea调试
- Arthas Command处理流程
- Arthas类查找和反编译原理
- Arthas内存动态编译原理
- Arthas动态重新加载类
- Arthas导出加载类
准备工作
这篇文章的主要目的是对Arthas的使用做一个简单的入门介绍，包含通过官方提供的demo来作-为被测试对象，通过官方提供的arthas包进行调试。
启动Demo
curl -O https://alibaba.github.io/arthas/arthas-demo.jar
java -jar arthas-demo.jar
arthas-demo是一个简单的程序，每隔一秒生成一个随机数，再执行质因数分解，并打印出分解结果。arthas-demo源代码：查看
- 启动arthas
curl -O https://alibaba.github.io/arthas/arthas-boot.jar
java -jar arthas-boot.jar
- 选择应用java进程
$ $ java -jar arthas-boot.jar
* [1]: 35542
[2]: 71560 arthas-demo.jar
[INFO] Try to attach process 71560
[INFO] Attach process 71560 success.
[INFO] arthas-client connect 127.0.0.1 3658
,---. ,------. ,--------.,--. ,--. ,---. ,---.
/ O \ | .--. ''--. .--'| '--' | / O \ ' .-'
| .-. || '--'.' | | | .--. || .-. |`. `-.
| | | || |\ \ | | | | | || | | |.-' |
`--' `--'`--' '--' `--' `--' `--'`--' `--'`-----'
wiki: https://alibaba.github.io/arthas
version: 3.0.5.20181127201536
pid: 71560
time: 2018-11-28 19:16:24
$
Demo进程是第2个，则输入2，再输入回车/enter。Arthas会attach到目标进程上，并输出日志。
命令帮助
[arthas@37711]$ help
NAME DESCRIPTION
help Display Arthas Help
keymap Display all the available keymap for the specified connection.
sc Search all the classes loaded by JVM
sm Search the method of classes loaded by JVM
classloader Show classloader info
jad Decompile class
getstatic Show the static field of a class
monitor Monitor method execution statistics, e.g. total/success/failure count, average rt, fail rate, etc.
stack Display the stack trace for the specified class and method
thread Display thread info, thread stack
trace Trace the execution time of specified method invocation.
watch Display the input/output parameter, return object, and thrown exception of specified method invocation
tt Time Tunnel
jvm Display the target JVM information
perfcounter Display the perf counter infornation.
ognl Execute ognl expression.
mc Memory compiler, compiles java files into bytecode and class files in memory.
redefine Redefine classes. @see Instrumentation#redefineClasses(ClassDefinition...)
dashboard Overview of target jvms thread, memory, gc, vm, tomcat info.
dump Dump class byte array from JVM
heapdump Heap dump
options View and change various Arthas options
cls Clear the screen
reset Reset all the enhanced classes
version Display Arthas version
session Display current session information
sysprop Display, and change the system properties.
sysenv Display the system env.
vmoption Display, and update the vm diagnostic options.
logger Print logger info, and update the logger level
history Display command history
cat Concatenate and print files
echo write arguments to the standard output
pwd Return working directory name
mbean Display the mbean information
grep grep command for pipes.
tee tee command for pipes.
profiler Async Profiler. https://github.com/jvm-profiling-tools/async-profiler
stop Stop/Shutdown Arthas server and exit the console.
功能展示
Arthas基本的命令通过help命令就可以看到了，这里我们选择几个比较好玩的命令展示一下。
dashboard - 当前系统的实时数据面板
[arthas@37711]$ dashboard --help
USAGE:
dashboard [-h] [-i <value>] [-n <value>]
SUMMARY:
Overview of target jvm's thread, memory, gc, vm, tomcat info.
EXAMPLES:
dashboard
dashboard -n 10
dashboard -i 2000
WIKI:
https://alibaba.github.io/arthas/dashboard
OPTIONS:
-h, --help this help
-i, --interval <value> The interval (in ms) between two executions, default is 5000 ms.
-n, --number-of-execution <value> The number of times this command will be executed.
thread - 查看当前线程信息，查看线程的堆栈
[arthas@37711]$ thread -h
USAGE:
thread [-h] [-b] [-i <value>] [--state <value>] [-n <value>] [id]
SUMMARY:
Display thread info, thread stack
EXAMPLES:
thread
thread 51
thread -n -1
thread -n 5
thread -b
thread -i 2000
thread --state BLOCKED
WIKI:
https://alibaba.github.io/arthas/thread
OPTIONS:
-h, --help this help
-b, --include-blocking-thread Find the thread who is holding a lock that blocks the most number of threads.
-i, --sample-interval <value> Specify the sampling interval (in ms) when calculating cpu usage.
--state <value> Display the thead filter by the state. NEW, RUNNABLE, TIMED_WAITING, WAITING, BLOCKED, TERMINATED is optional.
-n, --top-n-threads <value> The number of thread(s) to show, ordered by cpu utilization, -1 to show all.
<id> Show thread stack
tt - 记录方法执行信息
[arthas@37711]$ tt -h
USAGE:
tt [-d] [--delete-all] [-x <value>] [-h] [-i <value>] [-n <value>] [-l] [-p] [-E] [--replay-interval <value>] [--replay-times <value>] [-s <value>] [-M <value>] [-t] [-w <value>] [class-pattern] [meth
od-pattern] [condition-express]
SUMMARY:
Time Tunnel
The express may be one of the following expression (evaluated dynamically):
target : the object
clazz : the object's class
method : the constructor or method
params : the parameters array of method
params[0..n] : the element of parameters array
returnObj : the returned object of method
throwExp : the throw exception of method
isReturn : the method ended by return
isThrow : the method ended by throwing exception
#cost : the execution time in ms of method invocation
EXAMPLES:
tt -t *StringUtils isEmpty
tt -t *StringUtils isEmpty params[0].length==1
tt -l
tt -i 1000
tt -i 1000 -w params[0]
tt -i 1000 -p
tt -i 1000 -p --replay-times 3 --replay-interval 3000
tt --delete-all
WIKI:
https://alibaba.github.io/arthas/tt
sc - 查看JVM已加载的类信息
[arthas@37711]$ sc -h
USAGE:
sc [-c <value>] [-d] [-x <value>] [-f] [-h] [-E] class-pattern
SUMMARY:
Search all the classes loaded by JVM
EXAMPLES:
sc -d org.apache.commons.lang.StringUtils
sc -d org/apache/commons/lang/StringUtils
sc -d *StringUtils
sc -d -f org.apache.commons.lang.StringUtils
sc -E org\\.apache\\.commons\\.lang\\.StringUtils
WIKI:
https://alibaba.github.io/arthas/sc
OPTIONS:
-c, --classloader <value> The hash code of the special class's classLoader
-d, --details Display the details of class
-x, --expand <value> Expand level of object (0 by default)
-f, --field Display all the member variables
-h, --help this help
-E, --regex Enable regular expression to match (wildcard matching by default)
<class-pattern> Class name pattern, use either '.' or '/' as separator
watch - 方法执行数据观测
[arthas@37711]$ watch -h
USAGE:
watch [-b] [-e] [-x <value>] [-f] [-h] [-n <value>] [-E] [-M <value>] [-s] class-pattern method-pattern express [condition-express]
SUMMARY:
Display the input/output parameter, return object, and thrown exception of specified method invocation
The express may be one of the following expression (evaluated dynamically):
target : the object
clazz : the object's class
method : the constructor or method
params : the parameters array of method
params[0..n] : the element of parameters array
returnObj : the returned object of method
throwExp : the throw exception of method
isReturn : the method ended by return
isThrow : the method ended by throwing exception
#cost : the execution time in ms of method invocation
Examples:
watch -b org.apache.commons.lang.StringUtils isBlank params
watch -f org.apache.commons.lang.StringUtils isBlank returnObj
watch org.apache.commons.lang.StringUtils isBlank '{params, target, returnObj}' -x 2
watch -bf *StringUtils isBlank params
watch *StringUtils isBlank params[0]
watch *StringUtils isBlank params[0] params[0].length==1
watch *StringUtils isBlank params '#cost>100'
watch -E -b org\.apache\.commons\.lang\.StringUtils isBlank params[0]
WIKI:
https://alibaba.github.io/arthas/watch
trace - 输出方法路径上的节点耗时
- trace 能方便的帮助你定位和发现因 RT 高而导致的性能问题缺陷，但其每次只能跟踪一级方法的调用链路。
[arthas@37711]$ trace -h
USAGE:
trace [-h] [-n <value>] [-p <value>] [-E] [--skipJDKMethod <value>] class-pattern method-pattern [condition-express]
SUMMARY:
Trace the execution time of specified method invocation.
The express may be one of the following expression (evaluated dynamically):
target : the object
clazz : the object's class
method : the constructor or method
params : the parameters array of method
params[0..n] : the element of parameters array
returnObj : the returned object of method
throwExp : the throw exception of method
isReturn : the method ended by return
isThrow : the method ended by throwing exception
#cost : the execution time in ms of method invocation
EXAMPLES:
trace org.apache.commons.lang.StringUtils isBlank
trace *StringUtils isBlank
trace *StringUtils isBlank params[0].length==1
trace *StringUtils isBlank '#cost>100'
trace -E org\\.apache\\.commons\\.lang\\.StringUtils isBlank
trace -E com.test.ClassA|org.test.ClassB method1|method2|method3
trace demo.MathGame run -n 5
trace demo.MathGame run --skipJDKMethod false
WIKI:
https://alibaba.github.io/arthas/trace
OPTIONS:
-h, --help this help
-n, --limits <value> Threshold of execution times
-p, --path <value> path tracing pattern
-E, --regex Enable regular expression to match (wildcard matching by default)
--skipJDKMethod <value> skip jdk method trace, default value true.
<class-pattern> Class name pattern, use either '.' or '/' as separator
<method-pattern> Method name pattern
<condition-express> Conditional expression in ognl style, for example:
TRUE : 1==1
TRUE : true
FALSE : false
TRUE : 'params.length>=0'
FALSE : 1==2
profiler - 使用async-profiler生成火焰图
[arthas@37711]$ profiler -h
USAGE:
profiler [--allkernel] [--alluser] [-e <value>] [-f <value>] [--format <value>] [-h] [-i <value>] [--threads] action [actionArg]
SUMMARY:
Async Profiler. https://github.com/jvm-profiling-tools/async-profiler
EXAMPLES:
profiler start
profiler stop
profiler list # list all supported events
profiler actions # list all supported actions
profiler start --event alloc
profiler stop --format svg # output file format, support svg,html,jfr
profiler stop --file /tmp/result.html
profiler stop --threads
profiler status
profiler resume # Start or resume profiling without resetting collected data.
profiler getSamples # Get the number of samples collected during the profiling session
profiler dumpFlat # Dump flat profile, i.e. the histogram of the hottest methods
profiler dumpCollapsed # Dump profile in 'collapsed stacktraces' format
profiler dumpTraces # Dump collected stack traces
profiler execute 'start' # Execute an agent-compatible profiling command
profiler execute 'stop,file=/tmp/result.svg' # Execute an agent-compatible profiling command
