fossabot/ulyp

Preface

Ulyp is a proof-of-concept tracing instrumentation agent which records an execution of desired methods and sends them to UI. The agent should be provided only with two parameters: packages in which classes should be instrumented and a strating point in the following format: (simple class name).(method name). The starting point may be Runnable.run or it may contain a wildcard, like: UserDao.*.

The main purpose is mostly research of frameworks and troubleshooting of heavy enterprise applications where frameworks like Hibernate or Spring may call thousands of methods. Please note, the agent has very high performance impact and it's very intrusive.

Usage

Ulyp is bundled with very simple desktop UI written on JavaFX and agent itself.

Agent has the following props which are set as java system properties (via -Dkey=value)

Property	Mandatory	Default value	Example	Description
ulyp.ui-host	No	localhost	localhost	Target host for UI connection
ulyp.ui-port	No	13991	13991	Target port for UI connection
ulyp.max-depth	No	Integer.MAX_VALUE	20	Max depth of call trace tree. May be useful for limiting instrumentation data
ulyp.ui-port	No	13991	13991	Target port for UI connection
ulyp.log	No	-	Used as -Dulyp.log	Turns on agent logging

Example of running java app with the agent:

java -javaagent:C:\Work\Tools\ulyp-agent-0.1\ulyp-agent-0.1.jar -Dulyp.packages=com.demo,org.hibernate,org.h2 -Dulyp.start-method=JpaProxyUserRepositoryIntegrationTest.sampleTestCase YourClassName

Build

./gradlew clean build test

Simplest example: Fibbonaci numbers

package com.example;

public class FibbonaciTest {
    @Test
    public void test() {
	Assert.assertEquals(13, compute(7));
    }

    public static int compute(int n) {
	if (n <= 1)
	    return n;
	return compute(n - 1) + compute(n - 2);
    }
}

In order to activate ulyp the test should be executed with the following additional VM key:

-javaagent:C:\Work\ulyp\ulyp-agent\build\libs\ulyp-agent-0.2.jar

Specify "com" package to be instrumented and "FibbonaciTest.test" as tracing start method in UI and run the test:

Example (hibernate + h2 database)

Simple hibernate test recording:

@Autowired
private JpaProxyUserRepository repository;

@Test
public void sampleTestCase() {
	User dave = new User("Dave", "Mathews");
	dave = repository.save(dave);
}

The whole method traces tree may be investigated in the UI:

License