Spring Boot startup time: bean-by-bean diagnosis, and one directory per post

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.
2026-09-04 23:58:38 +05:30
parent 4b6cefa60a
commit 29676e0cc8
110 changed files with 2577 additions and 154 deletions
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+# The textbook AdminClient health check: bootstrap servers and nothing else.
+#
+# demo.kafka.timeout-ms is set far above Kafka's own default on purpose. It is NOT what bounds
+# the call here - the point of this profile is to let Kafka's default.api.timeout.ms (60000) be
+# the binding constraint and to measure it. See docs/06-health-indicator-failure-modes.md.
+demo:
+  kafka:
+    tuned: false
+    timeout-ms: 180000
+management:
+  endpoints:
+    web:
+      exposure:
+        include: health,info,diag
+  endpoint:
+    health:
+      show-details: always