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[Super Awesome Speaker] Nitsan Wakart presents JVM Profiler Mechanics

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Hosted By
Rory P. and Sizwe M.


About Nitsan:
A blogger ( and a coder with a pedantic passion for performance. My work has spanned army intelligence systems, era startups, financial institutions and innovative product companies. Currently the Lead Performance Eng. for Azul Systems ( by day, and main contributor to kickass lock free data structures library JCTools ( by night.

We will take a deep dive into the guts of Honest-Profiler, an unbiased sampling CPU profiler for the JVM, and the JVM internals which enable it to work.

• Introduction: CPU profiling, sampling and biases explained.

• How does it hang together? interrupts, non-blocking code and an unofficial API

• Sampling the instruction pointer: how it works and limits of accuracy

• Walking the stack: demangling a mixed Java/native stack, challenges and limitations

• Reading a profile: flat profile vs. tree profile vs. flamegraphs

The talk will include some counter examples from other profilers(JVisualVM/JMC/YourKit/ZVision).


18:00 - 19:00 Social and food

19:00 - 20:00 Nitsan Wakart

20:00 - 21:00 After party @ BBD

The sponsor for Nitsan's flights, accommodation ,the venue, food and drink is BBD.

The Jozi-JUG is dedicated to a harassment-free experience for everyone. Our anti-harassment policy can be found here (

1 Newtown Avenue, Killarney · Johannesburg