README.md

Dark Probe

(\,--------'()'--o
 (_    ___    /~"
  (_)_)  (_)_)
~~~  Mama never worry about your study! 
                           ~~~~~~~~~~~~ DARK_PROBE

DarkProbe is a javaAgent for inspecting method invoking chains in GLOBAL VIEWs, you can use it in learning principle of java middleware,
such as ZooKeeper, ElasticSearch, RocketMQ etc.

usage:

add to VM options:

-javaagent:{YOU AGENT JAR PATH NAME}/dark-probe.jar -DinspectPackage={PACKAGE NAMES YOU MONITOR}

example:

we can show you how this javaAgent affects ZooKeeper.

step 1: add to zookeeper VM startup parameters.

-javaagent:/home/work/??/dark-probe.jar -DinspectPackage=org.apache.zookeeper.server

step 2: run the ZooKeeper source code :

   // RUN org.apache.zookeeper.server.quorum.QuorumPeerMain#main
   public static void main(String[] args) {
       QuorumPeerMain main = new QuorumPeerMain();
       
       main.initializeAndRun(args);
       // ...
           
       
   }

step 3: console will output (from zookeeper)：

↗---------↘↙---↖
[main]go!↑↑ org.apache.zookeeper.server.quorum.QuorumPeerMain#main((String[])
[main]--------> org.apache.zookeeper.server.quorum.QuorumPeerMain#initializeAndRun(String[])
[main]----------> org.apache.zookeeper.server.quorum.QuorumPeerConfig#parse(String)
[main]------------> org.apache.zookeeper.server.util.VerifyingFileFactory#create(String)
[main]--------------> org.apache.zookeeper.server.util.VerifyingFileFactory#validate(File)
[main]----------------> org.apache.zookeeper.server.util.VerifyingFileFactory#doWarnForRelativePath(File)
[main]----------------> org.apache.zookeeper.server.util.VerifyingFileFactory#doFailForNonExistingPath(File)
[main]------------> org.apache.zookeeper.server.quorum.QuorumPeerConfig#parseProperties(Properties)
[main]--------------> org.apache.zookeeper.server.util.VerifyingFileFactory#create(String)
[main]----------------> org.apache.zookeeper.server.util.VerifyingFileFactory#validate(File)
[main]------------------> org.apache.zookeeper.server.util.VerifyingFileFactory#doWarnForRelativePath(File)
[main]--------------> org.apache.zookeeper.server.quorum.QuorumPeerConfig#setupQuorumPeerConfig(boolean, Properties)
[main]----------------> org.apache.zookeeper.server.quorum.QuorumPeerConfig#parseDynamicConfig(boolean, boolean, int, Properties)
[main]------------------> org.apache.zookeeper.server.quorum.QuorumPeerConfig#createQuorumVerifier(boolean, Properties)
[main]------------------> org.apache.zookeeper.server.quorum.flexible.QuorumMaj#getVotingMembers()
[main]------------------> org.apache.zookeeper.server.quorum.flexible.QuorumMaj#getObservingMembers()
[main]----------------> org.apache.zookeeper.server.quorum.QuorumPeerConfig#setupMyId()

The console outputs template is:

"↗---------↘↙---↖" 
[{thread name}]go↑↑ {1st root Class and method}
[{thread name}]--------> {2nd Class and method after 1st}
[{thread name}]------------> {3rd Class and method after 2nd}
[{thread name}]--------------> {4th Class and method after 3rd}

'1st root Class and method' meaning a new root method invoked (may from a new Thread),

If you are boring to see 'org.apache.zookeeper.server.metric.AvgMinMaxCounter' and 'org.apache.zookeeper.server.metric.AvgMinMaxPercentileCounter'
(or some class cause deadly recursive call ) ,just add VM options:

-DignorePackage=org.apache.zookeeper.server.metric.AvgMinMaxCounter,org.apache.zookeeper.server.metric.AvgMinMaxPercentileCounter

core

• JDK 1.8
• java instruments
• byteBuddy(bytebuddy.asm)
• java.lang.ThreadLocal