Java-debug-tool is a dynamic debugging tool. it provides some debugging commands to debug your code in runtime.
new features / bug fix / code clean / etc.
- java 8 + , java 7 support is on the way ...
- Unix like OS
- libc
wget https://github.com/pandening/storm-ml/releases/download/8.0/javadebug-tool-install.sh sh javadebug-tool-install.sh./javadebug-agent-launch.sh pid@ip:port ./javadebug-agent-launch.sh pid@ip ./javadebug-agent-launch.sh pidthe default port is 11234.
./javadebug-client-launch.sh ./javadebug-client-launch.sh ip:portJava-debug-tool including 2-part ability, debugging and profiling.
debug your code in runtime, the main command list :
- mt (method trace)
- fc (find class)
the simplest usage of 'mt' command like this :
mt -c [class name with package] -m [method name] there are many other options for mt command:
- timeout : set command execute timeout (seconds unit)
- t : the debug event type
- return : stop debug when method exit
- throw : stop debug when method throw exception
-
e ： the target exception class name [with package] -
tl : set the target invoked line, ref [line] -
te : set the target line's expression ref [line]
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- watch : stop debug when the params match
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i : the spring expression -
tl : set the target invoked line, ref [line] -
te : set the target line's expression ref [line]
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- custom : call method & debug itself
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i : the params -
tl : set the target invoked line, ref [line] -
te : set the target line's expression ref [line]
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- line : stop debug when special line is invoked(and the spring expression is true).
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tl : set the target invoked line -
te : set the target line's expression
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- record : record some method calls
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u : show the record method call with index [from 0 inc] -
n : the record count limit -
time : timeout for recording
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- l : just show the target line's debug info
for 'fc' command, it's very easy to use:
[case 1] you know the class name and want to find the class fc -class [class name] [case 2] you just want to find some classes by the regex fc -r [regex to match class] the 'l' option can set the output class limit. like this:
fc -r regex -l 10 java-debug-tool can profiling your code, there are some command can get the performance data in run time;
- thread
- monitor
- cputime
the thread command can get the cpu usage of each thread, and the call stack, and you can get the topN busy thread by this command:
thread command options:
- top : [topN] get the topN busy thread info
- status : [R(runnable)|W(waiting)|TW(timed waiting)|B(blocking)] get the target status' thread info
- tid : [thread id] get the thread info by thread id
monitor (aka collect) command options :
- t : the monitor event type, multi type can split with ',' like thread,mem
- thread : the thread statistic info
- mem : the mem info
- class : the class info
- gc : the gc info
- i : the interval (secs)
the default event is thread, the default interval is 5 seconds
the cputime command can get the cpu usage of the target jvm, the interval is 30 seconds, the base usage of this command is :
ct -o csv the 'o' option set the output format, you can set one from [csv,json]; the csv format is recommend, you need to wait 30 seconds before the command execute successfully. the output like this:
--------------------------------------------------------------------------------------------- Command ：ct Round ：1 ClientId ：10000 ClientType ：console:1 Version ：version:1 CommandCost ：32125 (ms) STW_Cost ：0 (ms) Time: : Mon Feb 03 17:33:10 CST 2020 --------------------------------------------------------------------------------------------- Start Time : Mon Feb 03 17:32:38 CST 2020 Stop Time : Mon Feb 03 17:33:10 CST 2020 Total cpu usage : 35.425249999999984 ms time;usr_ms;sys_ms;avg_usr_ms;avg_sys_ms;nivc_switch_per_sec;nvc_switch_per_sec 0;22.729;13.790;20.770;14.655;514;11 1;18.769;11.816;20.770;14.655;499;18 2;19.048;12.215;20.770;14.655;483;13 3;22.882;14.352;20.770;14.655;483;9 4;49.963;17.214;20.770;14.655;479;18 5;23.305;15.979;20.770;14.655;456;16 6;22.382;13.520;20.770;14.655;491;8 7;25.801;11.920;20.770;14.655;543;7 8;18.927;12.211;20.770;14.655;509;14 9;22.440;9.026;20.770;14.655;541;6 10;20.290;13.212;20.770;14.655;472;13 11;19.866;15.524;20.770;14.655;456;5 12;24.528;16.648;20.770;14.655;447;19 13;19.002;16.981;20.770;14.655;457;11 14;20.882;16.202;20.770;14.655;452;15 15;20.041;15.652;20.770;14.655;484;16 16;17.661;10.187;20.770;14.655;507;4 17;15.381;10.135;20.770;14.655;498;12 18;18.671;16.080;20.770;14.655;446;13 19;27.149;17.041;20.770;14.655;481;14 20;18.231;13.681;20.770;14.655;502;14 21;17.777;13.696;20.770;14.655;480;12 22;18.266;16.266;20.770;14.655;450;17 23;20.510;16.447;20.770;14.655;480;13 24;19.699;16.250;20.770;14.655;474;14 25;19.966;15.105;20.770;14.655;455;24 26;25.839;15.825;20.770;14.655;447;15 27;19.736;16.556;20.770;14.655;455;17 28;18.673;16.246;20.770;14.655;440;18 29;18.499;16.801;20.770;14.655;447;16 --------------------------------------------------------------------------------------------- - time : the time line
- usr_ms : user time mills
- sys_ms : system time mills
- avg_usr_ms : the avg user time mills
- avg_sys_ms : the avg system time mills
- nivc_switch_per_sec : the nivc switch per sec
- nvc_switch_per_sec ：the nvc switch per sec
| | | | | val | | | | | |_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ time line [0 - 29] for profiling, you can choose async-profiler which already including in bin path of java-debug-tool.
we will use a simple case to show the usage of java-debug-tool:
import java.util.Random; import java.util.concurrent.TimeUnit; public class Demo { private void say(String word, boolean tag, int rdm) { if (word == null) { word = "test say"; } int length = word.length(); if (tag) { length += 1; } else { length -= 1; } word += "@" + length; System.out.println(word); if (rdm > 5) { throw new IllegalStateException("test exception"); } } private static final String[] list = {"a", "ab", "abc", "abcd"}; public static void main(String[] args) { Demo demo = new Demo(); Random random = new Random(47); new Thread(new Runnable() { @Override public void run() { for(;;) { try { demo.say(list[random.nextInt(4)], random.nextBoolean(), random.nextInt(10)); TimeUnit.MILLISECONDS.sleep(100); } catch (Exception e) { e.printStackTrace(); } } } }, "demo-thread").start(); } }the 'mt' command (aka method trace) is the main command of java-debug-tool, this command can offer many runtime info of target method:
- Action time
- caller thread
- method params
- line cost
- invoked line number
- line variables
- return val
- exception
- call stack
using 'list' command to show all of the commands, then use 'help' command to get the usage of the command;
list h -cmd list h -cmd mt h -cmd monitor ... 
127.0.0.1:11234>list --------------------------------------------------------------------------------------------- Command ：list Round ：2 ClientId ：10000 ClientType ：console:1 Version ：version:1 CommandCost ：4 (ms) STW_Cost ：0 (ms) Time: : Sun Feb 02 17:22:20 CST 2020 --------------------------------------------------------------------------------------------- fc help list exit alive redefine rollback lock set info trace mt ct thread monitor btrace --------------------------------------------------------------------------------------------- 
127.0.0.1:11234>h -cmd list --------------------------------------------------------------------------------------------- Command ：h Round ：3 ClientId ：10000 ClientType ：console:1 Version ：version:1 CommandCost ：7 (ms) STW_Cost ：0 (ms) Time: : Sun Feb 02 17:22:39 CST 2020 --------------------------------------------------------------------------------------------- Command : list | all Function : list commands Usage : list | all Type : COMPUTE --------------------------------------------------------------------------------------------- 
-------------------------------------------------------------------------------- Thread Dynamic Statistic -------------------------------------------------------------------------------- ----- ----- ----- ----- tid name s cpu% ----- ----- ----- ----- 11 test-test-R-worker TW 95% 20 Java-Debug-Tool-WebSocket-Server-Worker R 5% Total Thread : 13, New : 0, Runnable : 7, Blocked : 0, Waiting : 4, Timed Waiting : 2, Terminated : 0 --- System Load --- AvailableProcessors 8 SystemLoadAverage 3.18652343 ProcessCpuLoad 0.01164025 -------------------------------------------------------------------------------- q 
127.0.0.1:11234>mt -c R -m call --------------------------------------------------------------------------------------------- Command ：mt Round ：6 ClientId ：10000 ClientType ：console:1 Version ：version:1 CommandCost ：411 (ms) STW_Cost ：68 (ms) Time: : Sun Feb 02 17:23:52 CST 2020 --------------------------------------------------------------------------------------------- [R.call] invoke by Thread:Thread[test-test-R-worker,5,main] with params [ [0] @class:java.lang.Integer -> 6, [1] @class:java.lang.Integer -> 6, [2] @class:C -> {"@class":"C","a":0}, [3] @unknown -> NULL, [4] @unknown -> NULL, [5] @unknown -> NULL, [6] @unknown -> NULL, [7] @class:java.util.ArrayList -> ["java.util.ArrayList",[{"@class":"R$MMM","data":"test"}]] ] [0 ms] (73) [mmmList1 = ["java.util.ArrayList",[{"@class":"R$MMM","data":"test"}]]] [0 ms] (74) [0 ms] (75) [0 ms] (79) [0 ms] (83) [el = -1] [0 ms] (84) [0 ms] (89) [0 ms] (93) [0 ms] (97) [0 ms] (99) [sa = 1] [0 ms] (100) [1 ms] (101) [ii = 0] [0 ms] (102) [ij = 0] [0 ms] (103) [jk = 1] [0 ms] (104) [f = 1.0] [0 ms] (105) [d = 0.123] [0 ms] (106) [name = "hello6,6"] [0 ms] (107) [list = ["java.util.ArrayList",[6,7]]] [0 ms] (108) [0 ms] (109) [0 ms] (110) [0 ms] (112) [0 ms] (115) [0 ms] (118) [0 ms] (119) throw exception:[java.lang.IllegalArgumentException: i + j <= 10:66] at line:119 with cost:3 ms -R.call -R$1.run at line:152 -java.lang.Thread.run at line:748 --------------------------------------------------------------------------------------------- - agent
the agent code, do attach work.
- core
the java-debug-tool's biz codes, including netty-handler, debug-client / debug-server, command handler, etc;
- test
the test module, test codes write here;
- script
the java-debug-tool's script dir;
- bin
the target bin dir;
cd script ./javadebug-pack.sh enjoy !
// // ======================================================================== // Copyright (c) 2018-2019 HuJian/Pandening soft collection. // ------------------------------------------------------------------------ // All rights reserved. This program and the accompanying materials // are made available under the terms of the #{license} Public License #{version} // EG: // The Eclipse Public License is available at // http://www.eclipse.org/legal/epl-v10.html // // The Apache License v2.0 is available at // http://www.opensource.org/licenses/apache2.0.php // // You may elect to redistribute this code under either of these licenses. // You should bear the consequences of using the software (named 'java-debug-tool') // and any modify must be create an new pull request and attach an text to describe // the change detail. // ======================================================================== // - Netty : Transport support.
- JLine : Console support.
- jna : java native access support.
- ASM : java bytecode weaver.
- arthas : java-debut-tool reference arthas.
- async-profiler : profiling support.
Thanks for the excellent work in these projects!