LinShunKang/MyPerf4J

What is it?

Key features

• 01Attaches via JavaAgent with no application code changes
• 02Per-method metrics including RPS, average, max, and TP50 to TP100 percentiles
• 03JVM metrics covering threads, memory, GC, classes, compilation and file descriptors
• 04One-second statistics granularity with every call recorded
• 05Output to log files, with InfluxDB and Grafana integration

Use cases

• Finding slow methods in a Java microservice under production load
• Monitoring JVM memory, GC and thread behavior over time
• Building Grafana dashboards for Java service performance

Quick start

1. 1

   Download and unzip MyPerf4J-ASM.zip, then edit MyPerf4J.properties

2. 2

   Add the Java agent and properties file to your JVM startup arguments

   java -javaagent:/path/to/MyPerf4J-ASM.jar -DMyPerf4JPropFile=/path/to/MyPerf4J.properties -jar yourApp.jar
3. 3

   Start the app and check /path/to/log/method_metrics.log for output

Things to know

• !Setup requires editing a properties file and JVM startup flags.
• !On JDK 9 and later, an extra --add-opens java.base/java.lang=ALL-UNNAMED flag is required.

In collections

Topics

FAQ

What is MyPerf4J?

A high-performance Java APM tool that collects method and JVM metrics via a Java agent, with no changes to application code. MyPerf4J is a Java application performance monitoring and statistics tool aimed at high-concurrency, low-latency services. It attaches to a JVM through a JavaAgent built on ASM bytecode instrumentation, so it can record method response times without changes to application code. Metrics include RPS, count, average, min, max, standard deviation and TP percentiles (TP50 through TP100) per method, along with JVM thread, memory, GC, class, compilation and file descriptor metrics.

Is MyPerf4J free to use? What license does it have?

MyPerf4J is open source under the BSD-3-Clause license. Check the license terms before using it in commercial products.

Is MyPerf4J still maintained?

Updated within 6 months. The last commit to MyPerf4J was on Jul 31, 2026.

What can I use MyPerf4J for?

Finding slow methods in a Java microservice under production load Monitoring JVM memory, GC and thread behavior over time Building Grafana dashboards for Java service performance

How do I install MyPerf4J?

Download and unzip MyPerf4J-ASM.zip, then edit MyPerf4J.properties Add the Java agent and properties file to your JVM startup arguments: java -javaagent:/path/to/MyPerf4J-ASM.jar -DMyPerf4JPropFile=/path/to/MyPerf4J.properties -jar yourApp.jar Start the app and check /path/to/log/method_metrics.log for output

Where can I get MyPerf4J?

The source code and installation instructions are on GitHub: https://github.com/LinShunKang/MyPerf4J