Benchmarking

A benchmark is simply a test that is used to compare similar products. A computer benchmarking program works by running a series of well-defined tests on the PC to measure its performance.

Side-effects to avoid:

• Garbage collection;
• IO operations;
• Extra tools, like IDE, gradle, etc -> run directly on VM.

To optimize, include warm-up iterations.

Java Microbenchmark Harness (JMH)

JMH is a Java harness for building, running, and analysing nano/micro/milli/macro benchmarks written in Java and other languages targeting the JVM.

Benchmark methods are annotated with the @Benchmark annotation.

Benchmark options:

• Forks (-f);
• Warmup Iterations (-wi);
• Iterations (-i);
• Warmup Iteration Duration (-w);
• Iteration Duration (-r);
• Time Unit (-u).

There is also a plugin for Gradle to run benchmarks: jmh-gradle-plugin.