post-PR-#91 follow-ups: SQLite cap warning + bash sim script

main.go

@@ -152,8 +152,9 @@ func main() {
 		fatal("DB/Env validation", err)
 	}
 	if strings.EqualFold(cfg.DBDriver, "sqlite") {
-		slog.Warn("SQLite driver in use — suitable for dev/small deployments only. " +
-			"Expected cap: ~5 services, ~1k events/sec sustained.")
+		slog.Warn("SQLite driver in use. Auto-tuned defaults survive ~50-120 services " +
+			"on a 4 GB host with 7-day retention. Switch to Postgres beyond that band, " +
+			"or for sustained >50 writes/sec. See README 'Production sizing'.")
 	}
 
 	// Initialize structured logger

test/run_simulation.sh

@@ -0,0 +1,211 @@
+#!/usr/bin/env bash
+# OtelContext chaos simulator — bash port of run_simulation.ps1.
+#
+# Builds 7 test microservices, starts them in the background, then hammers
+# their endpoints with N parallel HTTP workers. Each test service exports
+# OTLP to localhost:4317 — start the otelcontext binary first.
+#
+# Env knobs (all optional):
+#   WORKERS       parallel HTTP workers (default 10)
+#   DELAY_MS      ms between requests per worker (default 10)
+#   DURATION_SEC  stop after N seconds (default 0 = run until SIGINT)
+#   LOG_DIR       service stdout/stderr directory (default ../tmp/logs)
+#
+# Usage:
+#   ./test/run_simulation.sh                       # run forever
+#   DURATION_SEC=600 ./test/run_simulation.sh      # 10-minute run
+
+set -euo pipefail
+
+WORKERS=${WORKERS:-10}
+DELAY_MS=${DELAY_MS:-10}
+DURATION_SEC=${DURATION_SEC:-0}
+
+SCRIPT_DIR=$(cd "$(dirname "$0")" && pwd)
+ROOT_DIR=$(cd "$SCRIPT_DIR/.." && pwd)
+TMP_DIR="$ROOT_DIR/tmp"
+LOG_DIR="${LOG_DIR:-$TMP_DIR/logs}"
+STATS_DIR="$TMP_DIR/stats"
+
+# Services: name port
+SERVICES=(
+  "orderservice 9001"
+  "paymentservice 9002"
+  "inventoryservice 9003"
+  "authservice 9004"
+  "userservice 9005"
+  "shippingservice 9006"
+  "notificationservice 9007"
+)
+
+# Endpoints with weights — replicates the ps1 PickList expansion.
+ENDPOINTS=(
+  "POST http://localhost:9001/order 6"
+  "POST http://localhost:9002/pay 2"
+  "POST http://localhost:9003/check 2"
+  "POST http://localhost:9004/validate 1"
+  "POST http://localhost:9007/notify 1"
+)
+
+PICK_LIST=()
+for ep in "${ENDPOINTS[@]}"; do
+  read -r method url weight <<< "$ep"
+  for ((i=0; i<weight; i++)); do
+    PICK_LIST+=("$method $url")
+  done
+done
+PICK_COUNT=${#PICK_LIST[@]}
+
+mkdir -p "$TMP_DIR" "$LOG_DIR" "$STATS_DIR"
+rm -f "$STATS_DIR"/*.cnt "$STATS_DIR/.run"
+
+echo ""
+echo "======================================"
+echo "  OtelContext Chaos Simulation (bash)"
+echo "======================================"
+echo "  Workers  : $WORKERS"
+echo "  Delay    : ${DELAY_MS}ms / worker"
+if (( DURATION_SEC > 0 )); then
+  echo "  Duration : ${DURATION_SEC}s"
+else
+  echo "  Duration : continuous (Ctrl+C to stop)"
+fi
+echo ""
+
+# ── Build ────────────────────────────────────────────────────────────────────
+echo "[1/3] Building test services..."
+for entry in "${SERVICES[@]}"; do
+  read -r name port <<< "$entry"
+  printf "  %-26s " "$name"
+  (cd "$ROOT_DIR" && go build -o "$TMP_DIR/$name" "./test/$name") >/dev/null
+  echo "built"
+done
+echo "  All services built."
+
+# ── Start services ───────────────────────────────────────────────────────────
+echo ""
+echo "[2/3] Starting services..."
+declare -a SVC_PIDS=()
+for entry in "${SERVICES[@]}"; do
+  read -r name port <<< "$entry"
+  "$TMP_DIR/$name" > "$LOG_DIR/$name.stdout" 2> "$LOG_DIR/$name.stderr" &
+  pid=$!
+  SVC_PIDS+=("$pid")
+  printf "  %-26s PID %6d  :%s\n" "$name" "$pid" "$port"
+done
+
+cleanup() {
+  echo ""
+  echo "[cleanup] Stopping services..."
+  rm -f "$STATS_DIR/.run"
+  for pid in "${SVC_PIDS[@]}"; do
+    kill -TERM "$pid" 2>/dev/null || true
+  done
+  wait "${SVC_PIDS[@]}" 2>/dev/null || true
+  echo "  Done. Logs in: $LOG_DIR"
+}
+trap cleanup EXIT INT TERM
+
+echo "  Waiting 4s for services to bind ports..."
+sleep 4
+
+# ── Workers ──────────────────────────────────────────────────────────────────
+echo ""
+echo "[3/3] Running load..."
+echo ""
+
+START=$(date +%s)
+DEADLINE=0
+if (( DURATION_SEC > 0 )); then
+  DEADLINE=$(( START + DURATION_SEC ))
+fi
+
+worker() {
+  local id=$1
+  local cnt_file="$STATS_DIR/$id.cnt"
+  local total=0 ok=0 fail=0
+  local sleep_s
+  sleep_s=$(awk "BEGIN {printf \"%.3f\", $DELAY_MS/1000}")
+
+  while [[ -f "$STATS_DIR/.run" ]]; do
+    local idx=$((RANDOM % PICK_COUNT))
+    local ep="${PICK_LIST[$idx]}"
+    local method url
+    read -r method url <<< "$ep"
+
+    if curl -fsS -X "$method" -m 8 -o /dev/null "$url" 2>/dev/null; then
+      ok=$((ok+1))
+    else
+      fail=$((fail+1))
+    fi
+    total=$((total+1))
+
+    # Flush every 10 requests to amortise file IO.
+    if (( total % 10 == 0 )); then
+      printf "%d %d %d\n" "$total" "$ok" "$fail" > "$cnt_file"
+    fi
+
+    sleep "$sleep_s"
+  done
+  printf "%d %d %d\n" "$total" "$ok" "$fail" > "$cnt_file"
+}
+
+touch "$STATS_DIR/.run"
+
+declare -a WORKER_PIDS=()
+for ((i=0; i<WORKERS; i++)); do
+  worker "$i" &
+  WORKER_PIDS+=("$!")
+done
+
+LAST_TOTAL=0
+while true; do
+  sleep 1
+  NOW=$(date +%s)
+  ELAPSED=$((NOW - START))
+
+  TOTAL=0; OK=0; FAIL=0
+  shopt -s nullglob
+  for f in "$STATS_DIR"/*.cnt; do
+    read -r t o fa < "$f"
+    TOTAL=$((TOTAL + t))
+    OK=$((OK + o))
+    FAIL=$((FAIL + fa))
+  done
+  shopt -u nullglob
+
+  DELTA=$((TOTAL - LAST_TOTAL))
+  LAST_TOTAL=$TOTAL
+  RPS=$(( ELAPSED > 0 ? TOTAL / ELAPSED : 0 ))
+  ERR_PCT=$(( TOTAL > 0 ? FAIL * 100 / TOTAL : 0 ))
+
+  printf "  %6ds | Total: %7d | OK: %7d | Fail: %5d | Err: %4d%% | %5d req/s | +%d/s\n" \
+    "$ELAPSED" "$TOTAL" "$OK" "$FAIL" "$ERR_PCT" "$RPS" "$DELTA"
+
+  if (( DEADLINE > 0 && NOW >= DEADLINE )); then
+    break
+  fi
+done
+
+rm -f "$STATS_DIR/.run"
+for pid in "${WORKER_PIDS[@]}"; do
+  wait "$pid" 2>/dev/null || true
+done
+
+ERR_COL=
+if   (( ERR_PCT > 20 )); then ERR_COL="!"
+elif (( ERR_PCT >  5 )); then ERR_COL="~"
+else                          ERR_COL=" "
+fi
+
+echo ""
+echo "======================================"
+echo "  Simulation Complete"
+echo "======================================"
+echo "  Duration  : ${ELAPSED}s"
+echo "  Requests  : $TOTAL"
+echo "  Success   : $OK"
+echo "  Failed    : $FAIL"
+echo "  Error Rate: ${ERR_PCT}% ${ERR_COL}"
+echo "  Avg RPS   : $RPS"
+echo ""