JVM JIT compilation metrics example

Required Java version

Since this app uses JEP 349: JFR Event Streaming, need to use Java 14 or later.

JEP 349: https://openjdk.java.net/jeps/349

Preparation

Launch local Docker registry

$ docker run -d -p 5000:5000 --name registry registry:2.6

How to build and push to the local Docker registry

$ make docker-push-app
$ make docker-push-mtail

How to deploy to a local k8s cluster

$ make kubectl-create-example

How to delete the app from a local k8s cluster

$ make kubectl-delete-example

How to load for JIT compilation

*This command uses Apache Bench

$ make load-test

---

Exported JIT compilation metrics

By Micrometer

setting: JitCompilationMetrics.java

# HELP jvm_jit_compilation_total  
# TYPE jvm_jit_compilation_total counter
jvm_jit_compilation_total{package="java.util",} 333.0
jvm_jit_compilation_total{package="org.springframework.context",} 29.0
...

By mtail

setting: jvm-jit-compilation.mtail

# HELP mtail_jvm_jit_compilation_total defined at jvm-jit-compilation.mtail:1:9-39
# TYPE mtail_jvm_jit_compilation_total counter
mtail_jvm_jit_compilation_total{filename="/app/jvm-unified-log/jit-compilation.log",package="java.util",prog="jvm-jit-compilation.mtail"} 1921
mtail_jvm_jit_compilation_total{filename="/app/jvm-unified-log/jit-compilation.log",package="java.util.concurrent",prog="jvm-jit-compilation.mtail"} 369
mtail_jvm_jit_compilation_total{filename="/app/jvm-unified-log/jit-compilation.log",package="org.springframework.util",prog="jvm-jit-compilation.mtail"} 554
...

Example PromQL

http://localhost:30000/graph?g0.range_input=5m&g0.expr=jvm_jit_compilation_total&g0.tab=0&g1.range_input=5m&g1.expr=mtail_jvm_jit_compilation_total&g1.tab=0&g2.range_input=5m&g2.expr=mtail_log_lines_total&g2.tab=0