TL;DR

Ulyp instruments all third-party library classes and record their method calls including return values and arguments, so that you can have a better understanding of what your code and frameworks do, find inefficiencies, debug faster. Instrumentation is done by byte-buddy library. All data is saved to a file during recording. No clouds uploads, server, etc. UI is a desktop app written using JavaFX.

Here is the basic example of recorded execution of Hibernate framework

```
@Transactional
public void save(Person person) {
    personRepository.save(person);
}
```

How to use

Usage is relatively simple.

• First, download or build the agent

• Second, use VM properties in order to enable the recording. Here is the minimum set of options one will need for recording.

  -javaagent:/path/to/ulyp-agent-1.0.0.jar
  -Dulyp.methods=**.HibernateShowcase.*
  -Dulyp.file=/tmp/recording.dat
  

Recording starts when any method of a class which has class name HibernateShowcase is called. The data is written to the specified file which can later be opened in the UI.

Examples of method matchers are:

Matcher	Explanation
org.springframework.**.Service.*	Record any method of class Service in package org.springframework (or nested) package
**.Runnable.run	Record all Runnable instances
*.*	Record all calls (Experimental)

Options

The agent is controlled via JVM system properties.

Property	Description	Example	Default
ulyp.file	A path to a file where all recording data should be written	-Dulyp.file=/tmp/test.dat	-
ulyp.methods	A list of method matchers where recording should start	-Dulyp.methods=**.Runnable.run	Main method
ulyp.start	Controls when recording can start. default is start recording any time when some of ulyp.method is called. Another option is delay:X where X is the number of seconds to wait from the app launch, api - remote enable/disable (WIP)	-Dulyp.start=delay:120	default
ulyp.packages	A list of packages to instrument	-Dulyp.packages=org.springframework,io.grpc	All packages
ulyp.record-timestamps	Record duration of calls	-Dulyp.record-timestamps	Disabled
ulyp.exclude-packages	A list of packages to exclude from instrumentation	-Dulyp.exclude-packages=org.springframework	-
ulyp.exclude-types	A list of type matchers to exclude from instrumentation	-Dulyp.exclude-types=org.springframework.**.Interceptor	-
ulyp.record-constructors	Enables instrumentation (and possibly recording) of constructors	-Dulyp.record-constructors	Disabled
ulyp.record-collections	Records values (some number of items) of collections. Possible values are: NONE, JDK (only JDK collections), ALL (dangerous)	-Dulyp.record-collections=JDK	NONE
ulyp.record-collections.max-items	Max items of collections to record	-Dulyp.record-collections.max-items=5	3
ulyp.record-arrays	Records values (some number of items) of arrays	-Dulyp.record-arrays	Disabled
ulyp.record-arrays.max-items	Max items of arrays to record	-Dulyp.record-arrays.max-items=10	3
ulyp.record-lambdas	Enabled instrumentation (and possibly recording) of lambdas (experimental)	-Dulyp.record-lambdas	Disabled
ulyp.record-static-blocks	Enabled instrumentation (and possibly recording) of static blocks (experimental)	-Dulyp.record-static-blocks	Disabled
ulyp.print-types	A list of type matchers to print with toString() while recording their values	-Dulyp.print-types=com.enterprise.**.SomeEntity	-

UI

Controls

Hotkey	Action
Hold Shift	Show full type names
Hold X	Show method call duration (if enabled with -Dulyp.record-timestamps while recording)
Press =	Increase font size
Press -	Decrease font size

Build from source

Build agent (no tests): ./gradlew :ulyp-agent:shadowJar

Build UI jar file (Java 11+ (preferred) or Java 8 Oracle with Java FX bundled) : ./gradlew :ulyp-ui:fatJar

UI jar file for a particular platform can be built as follows: ./gradlew :ulyp-ui:fatJar -Pplatform=mac

Available platforms for the build are: linux, linux-aarch64, win, mac, mac-aarch64