Add jdk27-perf: the same Spring Boot service measured on JDK 25 and JDK 27

Live heap, throughput, p99 and startup across four configurations, including opt-in and opt-out of compact object headers. Co-Authored-By: Claude Sonnet 5.5 <[email protected]> Claude-Session: https://claude.ai/code/session_01WzVQ6zFh9cuLPj9RSbRH8U
2026-10-12 17:30:55 +00:00
parent fc05eed4b5
commit d565be93c6
13 changed files with 388 additions and 1 deletions
@@ -0,0 +1,42 @@
+import java.net.URI;
+import java.net.http.*;
+import java.util.*;
+import java.util.concurrent.*;
+import java.util.concurrent.atomic.*;
+
+/** Closed-loop load: THREADS threads, WARMUP seconds discarded, then MEASURE seconds recorded. */
+public class Load {
+    public static void main(String[] a) throws Exception {
+        int port = Integer.parseInt(a[0]), warmup = Integer.parseInt(a[1]), measure = Integer.parseInt(a[2]), threads = Integer.parseInt(a[3]);
+        HttpClient c = HttpClient.newBuilder().version(HttpClient.Version.HTTP_1_1).build();
+        HttpRequest rq = HttpRequest.newBuilder(URI.create("http://localhost:" + port + "/quote?n=200")).build();
+        long start = System.nanoTime();
+        long measureFrom = start + warmup * 1_000_000_000L, end = measureFrom + measure * 1_000_000_000L;
+        List<long[]> perThread = new CopyOnWriteArrayList<>();
+        ExecutorService ex = Executors.newFixedThreadPool(threads);
+        List<Future<?>> fs = new ArrayList<>();
+        for (int t = 0; t < threads; t++) fs.add(ex.submit(() -> {
+            long[] buf = new long[2_000_000]; int n = 0;
+            try {
+                while (true) {
+                    long s = System.nanoTime();
+                    if (s >= end) break;
+                    c.send(rq, HttpResponse.BodyHandlers.discarding());
+                    long e = System.nanoTime();
+                    if (s >= measureFrom && n < buf.length) buf[n++] = e - s;
+                }
+            } catch (Exception e) { throw new RuntimeException(e); }
+            perThread.add(Arrays.copyOf(buf, n));
+            return null;
+        }));
+        for (Future<?> f : fs) f.get();
+        ex.shutdown();
+        long total = 0; for (long[] b : perThread) total += b.length;
+        long[] all = new long[(int) total]; int p = 0;
+        for (long[] b : perThread) { System.arraycopy(b, 0, all, p, b.length); p += b.length; }
+        Arrays.sort(all);
+        System.out.printf("requests=%d throughput=%.0f req/s p50=%.2f ms p99=%.2f ms p99.9=%.2f ms max=%.2f ms%n",
+            total, total / (double) measure, all[(int) (total * 0.50)] / 1e6, all[(int) (total * 0.99)] / 1e6,
+            all[(int) (total * 0.999)] / 1e6, all[(int) total - 1] / 1e6);
+    }
+}
@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+# Usage: live-set.sh <java-home> <label> [jvm args...]
+# Starts the server, forces a full GC through /live, and prints the heap still in use.
+# This is the resident data set: 3,000,000 two-int records plus the Spring Boot baseline.
+set -u
+JH=$1; LABEL=$2; shift 2
+JAR="$(dirname "$0")/../target/jdk27-perf-1.0.0.jar"
+PORT=${PORT:-18082}
+"$JH/bin/java" "$@" -jar "$JAR" --server.port=$PORT --spring.main.banner-mode=off \
+    --logging.level.root=WARN > /dev/null 2>&1 &
+PID=$!
+until [ "$(curl -s -o /dev/null -m 2 -w '%{http_code}' "localhost:$PORT/stats")" = 200 ]; do sleep 0.05; done
+live=$(curl -s "localhost:$PORT/live" | sed -n 's/.*"liveHeapMiB":\([0-9]*\).*/\1/p')
+echo "$LABEL: live heap after full GC ${live} MiB"
+kill $PID 2>/dev/null; wait $PID 2>/dev/null
@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+# Regenerates output/. Set J25 and J27. REPS defaults to 3. Configs are interleaved per repetition
+# so slow drift on the machine hits every configuration equally. Timings are indicative only.
+set -u
+HERE="$(cd "$(dirname "$0")" && pwd)"
+OUT="$HERE/../output"; mkdir -p "$OUT"
+: "${J25:?}" "${J27:?}"
+export JDK_CLIENT="$J25"
+REPS=${REPS:-3}
+{
+  for p in "25|$J25" "27|$J27"; do
+    v=${p%%|*}; h=${p#*|}
+    echo "== JDK $v"
+    "$h/bin/java" -version 2>&1 | grep -v Picked | sed -n 1p
+    "$h/bin/java" -XX:+PrintFlagsFinal -version 2>&1 | grep -E ' (UseCompactObjectHeaders|UseG1GC|UseSerialGC|UseZGC|MaxHeapSize) ' | sed 's/ \{2,\}/ /g'
+    echo
+  done
+} > "$OUT/01-defaults.txt"
+: > "$OUT/02-runs.txt"
+for r in $(seq 1 "$REPS"); do
+  "$HERE/run-one.sh" "$J25" "jdk25 defaults"                       >> "$OUT/02-runs.txt" 2>&1
+  "$HERE/run-one.sh" "$J25" "jdk25 +CompactObjectHeaders" -XX:+UseCompactObjectHeaders >> "$OUT/02-runs.txt" 2>&1
+  "$HERE/run-one.sh" "$J27" "jdk27 defaults"                       >> "$OUT/02-runs.txt" 2>&1
+  "$HERE/run-one.sh" "$J27" "jdk27 -CompactObjectHeaders" -XX:-UseCompactObjectHeaders >> "$OUT/02-runs.txt" 2>&1
+done
+"$HERE/summarize.sh" "$OUT/02-runs.txt" > "$OUT/03-summary.txt"
+# 04 - resident data set after a forced full GC (this is where compact headers show up)
+{
+  for r in 1 2 3; do
+    "$HERE/live-set.sh" "$J25" "jdk25 defaults"
+    "$HERE/live-set.sh" "$J25" "jdk25 +CompactObjectHeaders" -XX:+UseCompactObjectHeaders
+    "$HERE/live-set.sh" "$J27" "jdk27 defaults"
+    "$HERE/live-set.sh" "$J27" "jdk27 -CompactObjectHeaders" -XX:-UseCompactObjectHeaders
+  done
+} > "$OUT/04-live-set.txt" 2>&1
@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+# Usage: run-one.sh <java-home> <label> [jvm args...]
+# One cold start, then 15 s warmup + 30 s measured load, then a /stats snapshot. One result block.
+set -u
+JH=$1; LABEL=$2; shift 2
+HERE="$(cd "$(dirname "$0")" && pwd)"
+JAR="$HERE/../target/jdk27-perf-1.0.0.jar"
+PORT=${PORT:-18081}
+CLIENT=${JDK_CLIENT:-$JH}
+t0=$(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=$!
+until [ "$(curl -s -o /dev/null -m 2 -w '%{http_code}' "localhost:$PORT/stats")" = 200 ]; do sleep 0.02; done
+t1=$(date +%s%N)
+echo "== $LABEL"
+echo "startup_ms=$(( (t1 - t0) / 1000000 ))"
+"$CLIENT/bin/java" "$HERE/Load.java" $PORT 15 30 ${THREADS:-4} 2>&1 | grep -v Picked
+curl -s "localhost:$PORT/stats"; echo
+kill $PID 2>/dev/null; wait $PID 2>/dev/null
@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+# Usage: summarize.sh output/02-runs.txt  -> median of each metric per label
+awk '
+/^== /{label=substr($0,4); next}
+/^startup_ms=/{split($0,a,"="); st[label]=st[label] " " a[2]}
+/^requests=/{for(i=1;i<=NF;i++){split($i,kv,"="); if(kv[1]=="throughput")tp[label]=tp[label] " " kv[2]; if(kv[1]=="p99")p99[label]=p99[label] " " kv[2]}}
+/^\{"javaVersion"/{match($0,/"heapUsedMiB":[0-9]+/); h=substr($0,RSTART+14,RLENGTH-14); hu[label]=hu[label] " " h; match($0,/"rssMiB":[0-9]+/); r=substr($0,RSTART+9,RLENGTH-9); rss[label]=rss[label] " " r}
+function med(s,  n,arr,i,j,t){n=split(s,arr," "); for(i=1;i<=n;i++)for(j=i+1;j<=n;j++)if(arr[j]+0<arr[i]+0){t=arr[i];arr[i]=arr[j];arr[j]=t}; return arr[int((n+1)/2)]}
+END{for(l in st) printf "%s | startup %s ms | throughput %s req/s | p99 %s ms | heap used %s MiB | RSS %s MiB\n", l, med(st[l]), med(tp[l]), med(p99[l]), med(hu[l]), med(rss[l])}' "$1" | sort