Ankur Mhatre
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.
26 lines
988 B
Bash
Executable File
26 lines
988 B
Bash
Executable File
#!/usr/bin/env bash
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# What a too-small buffer does. Every guide picks 2048; nobody says what happens when
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# an application produces more steps than that.
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set -uo pipefail
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source "$(dirname "$0")/env.sh"
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for cap in 2048 16384; do
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"$(dirname "$0")/stop.sh"
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"$JAVA_HOME/bin/java" -Dstartup.tracking=buffering -Dstartup.buffer=$cap \
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-jar "$JAR" > /tmp/buf.log 2>&1 &
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PID=$!
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for _ in $(seq 1 240); do curl -fs -o /dev/null localhost:8080/actuator/health && break; sleep 0.5; done
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ok=$?
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echo "--- capacity $cap ---"
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if grep -q 'Started StartupDiagnosisApplication' /tmp/buf.log; then
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echo -n " started, recorded steps: "
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curl -s 'localhost:8080/diag/startup?top=1' \
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| python3 -c "import sys,json;print(json.load(sys.stdin)['recordedSteps'])"
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else
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echo " application did not start. Last lines of the log:"
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grep -E 'ERROR|Exception|Caused by' /tmp/buf.log | head -5 | sed 's/^/ /'
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fi
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kill -9 $PID 2>/dev/null; wait $PID 2>/dev/null
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done
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true
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