Add jdk28-zgc: ZGC startup and warmup baseline on JDK 25/27/28-ea, and a probe for JEP 545/546

Spring Boot 4.1.1 harness measuring first-response time versus initial heap size and a 20,000-request warmup. Shows -XX:+ZAdaptiveHeapSizing is not yet in any build. Co-Authored-By: Claude Sonnet 5.5 <[email protected]> Claude-Session: https://claude.ai/code/session_01WzVQ6zFh9cuLPj9RSbRH8U
2026-10-12 17:13:14 +00:00
parent 2f88734f5d
commit df13a904d7
11 changed files with 431 additions and 0 deletions
@@ -0,0 +1,32 @@
+#!/usr/bin/env bash
+# Usage: startup.sh <java-home> <label> <runs> [jvm args...]
+# Starts the Spring Boot jar, polls /hello until HTTP 200, and prints wall-clock ms from
+# process start to first response plus the committed heap one second later. One line per run,
+# then a summary line (min / median / max).
+set -u
+JH=$1; LABEL=$2; RUNS=$3; shift 3
+JAR="$(dirname "$0")/../target/jdk28-zgc-1.0.0.jar"
+PORT=${PORT:-18080}
+times=()
+for r in $(seq 1 "$RUNS"); do
+  t0=$(date +%s%N)
+  "$JH/bin/java" "$@" -jar "$JAR" --server.port=$PORT --spring.main.banner-mode=off \
+      --logging.level.root=WARN > /dev/null 2>&1 &
+  PID=$!
+  while :; do
+    code=$(curl -s -o /dev/null -m 1 -w '%{http_code}' "localhost:$PORT/hello")
+    [ "$code" = 200 ] && break
+    kill -0 $PID 2>/dev/null || { echo "$LABEL run $r: JVM exited early"; break; }
+    sleep 0.02
+  done
+  t1=$(date +%s%N)
+  ms=$(( (t1 - t0) / 1000000 ))
+  sleep 1
+  committed=$(curl -s "localhost:$PORT/heap" | sed -n 's/.*"committedMiB":\([0-9]*\).*/\1/p')
+  echo "$LABEL run $r: first-response ${ms} ms, committed heap ${committed} MiB"
+  times+=("$ms")
+  kill $PID 2>/dev/null; wait $PID 2>/dev/null
+done
+sorted=($(printf '%s\n' "${times[@]}" | sort -n))
+n=${#sorted[@]}
+echo "$LABEL SUMMARY: min ${sorted[0]} ms, median ${sorted[$((n/2))]} ms, max ${sorted[$((n-1))]} ms (n=$n)"