asmhatre
958b401f0f
Adds spring-boot-startup-time/, the companion project for BLOG-618: a runnable Spring Boot 4.1.1 application on JDK 25 that installs BufferingApplicationStartup and FlightRecorderApplicationStartup behind a system property, and a /diag/startup endpoint that computes step self time -- the number /actuator/startup does not give you and the one that names the actual culprits. Captured under docs/output/: the step tree sorted both ways, the same startup as JFR events, a +5000-class experiment putting 0.11 ms per scanned class on the classpath scan tax, the silent truncation a 2048-step buffer performs, and JDK 25 AOT cache timings (6.93 s to 4.82 s). Post body and metadata live in post/. Moves the existing Actuator project into actuator-in-production/ so the repository holds one directory per article; the root README is now an index.
25 lines
1.1 KiB
Java
25 lines
1.1 KiB
Java
package com.ankurm.startup;
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import org.springframework.boot.SpringApplication;
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import org.springframework.boot.autoconfigure.SpringBootApplication;
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import org.springframework.boot.context.metrics.buffering.BufferingApplicationStartup;
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import org.springframework.core.metrics.jfr.FlightRecorderApplicationStartup;
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@SpringBootApplication
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public class StartupDiagnosisApplication {
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public static void main(String[] args) {
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SpringApplication app = new SpringApplication(StartupDiagnosisApplication.class);
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String mode = System.getProperty("startup.tracking", "buffering");
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// The capacity is the number of *steps*, not beans, and there is no way to change it
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// after construction. See docs/07-failure-modes.md for what a too-small buffer does.
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int capacity = Integer.getInteger("startup.buffer", 16384);
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switch (mode) {
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case "buffering" -> app.setApplicationStartup(new BufferingApplicationStartup(capacity));
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case "jfr" -> app.setApplicationStartup(new FlightRecorderApplicationStartup());
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default -> { }
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}
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app.run(args);
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}
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}
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