import http from "k6/http";
import { check } from "k6";
import { Counter, Rate, Trend } from "k6/metrics";
// ── Custom metrics ──────────────────────────────────────────────────────
const jsExecDuration = new Trend("js_exec_duration", true);
const jsExecSuccess = new Rate("js_exec_success");
const jsExecCount = new Counter("js_exec_count");
// ── Configuration from environment ──────────────────────────────────────
// TARGET_URLS: comma-separated list of base URLs (for cluster round-robin)
const TARGET_URLS = (__ENV.TARGET_URLS || __ENV.TARGET_URL || "http://localhost:3001")
.split(",")
.map((u) => u.trim());
const TARGET_RATE = parseInt(__ENV.TARGET_RATE || "1000");
const DURATION = __ENV.DURATION || "60s";
const TOPOLOGY = __ENV.TOPOLOGY || "unknown";
// ── Scenario configuration ──────────────────────────────────────────────
// constant-arrival-rate attempts exactly TARGET_RATE iterations/sec
// regardless of response time.
export const options = {
scenarios: {
mcp_load: {
executor: "constant-arrival-rate",
rate: TARGET_RATE,
timeUnit: "1s",
duration: DURATION,
preAllocatedVUs: Math.min(Math.ceil(TARGET_RATE * 0.1), 500),
maxVUs: Math.min(TARGET_RATE, 5000),
},
},
summaryTrendStats: ["avg", "min", "med", "max", "p(90)", "p(95)", "p(99)"],
thresholds: {
js_exec_success: ["rate>0.90"],
js_exec_duration: ["p(95)<10000", "p(99)<30000"],
},
tags: {
topology: TOPOLOGY,
target_rate: String(TARGET_RATE),
},
};
// Lightweight JS snippets — rotate to avoid caching effects.
const JS_SNIPPETS = [
"1 + 1",
"Math.sqrt(144)",
"JSON.stringify({a: 1, b: 2})",
"Array.from({length: 10}, (_, i) => i * i).reduce((a, b) => a + b, 0)",
"'hello'.repeat(3)",
"Date.now()",
"Object.keys({x: 1, y: 2, z: 3}).length",
"[1,2,3,4,5].filter(n => n % 2 === 0).map(n => n * 10)",
];
const HEADERS = { "Content-Type": "application/json" };
// Simple round-robin counter for distributing across cluster nodes.
let rrCounter = 0;
function pickUrl() {
const url = TARGET_URLS[rrCounter % TARGET_URLS.length];
rrCounter++;
return url;
}
// ── Main test function ──────────────────────────────────────────────────
// Each iteration: single POST /api/exec with JSON body
export default function () {
const baseUrl = pickUrl();
const snippet = JS_SNIPPETS[Math.floor(Math.random() * JS_SNIPPETS.length)];
const payload = JSON.stringify({ code: snippet });
const res = http.post(`${baseUrl}/api/exec`, payload, {
headers: HEADERS,
timeout: "10s",
});
jsExecDuration.add(res.timings.duration);
jsExecCount.add(1);
const ok = check(res, {
"status 200": (r) => r.status === 200,
"has output": (r) => {
try {
const body = JSON.parse(r.body);
return body.output !== undefined && !String(body.output).startsWith("Error:");
} catch (_) {
return false;
}
},
});
jsExecSuccess.add(ok);
}
// ── Summary ─────────────────────────────────────────────────────────────
export function handleSummary(data) {
const summary = {
topology: TOPOLOGY,
target_rate: TARGET_RATE,
duration: DURATION,
target_urls: TARGET_URLS,
metrics: {
js_exec_count:
data.metrics.js_exec_count
? data.metrics.js_exec_count.values.count
: 0,
js_exec_success_rate:
data.metrics.js_exec_success
? data.metrics.js_exec_success.values.rate
: 0,
js_exec_duration_avg:
data.metrics.js_exec_duration
? data.metrics.js_exec_duration.values.avg
: 0,
js_exec_duration_p95:
data.metrics.js_exec_duration
? data.metrics.js_exec_duration.values["p(95)"]
: 0,
js_exec_duration_p99:
data.metrics.js_exec_duration
? data.metrics.js_exec_duration.values["p(99)"]
: 0,
http_req_duration_avg:
data.metrics.http_req_duration
? data.metrics.http_req_duration.values.avg
: 0,
http_req_duration_p95:
data.metrics.http_req_duration
? data.metrics.http_req_duration.values["p(95)"]
: 0,
http_reqs_per_sec:
data.metrics.http_reqs
? data.metrics.http_reqs.values.rate
: 0,
iterations_per_sec:
data.metrics.iterations
? data.metrics.iterations.values.rate
: 0,
vus_max:
data.metrics.vus_max
? data.metrics.vus_max.values.max
: 0,
dropped_iterations:
data.metrics.dropped_iterations
? data.metrics.dropped_iterations.values.count
: 0,
},
};
const filename = `results-${TOPOLOGY}-${TARGET_RATE}rps.json`;
const output = {};
output[filename] = JSON.stringify(summary, null, 2);
output["stdout"] = textSummary(data);
return output;
}
function safeFixed(val, digits) {
return val != null ? val.toFixed(digits) : "N/A";
}
function textSummary(data) {
let out = `\n${"=".repeat(60)}\n`;
out += ` Load Test Results: ${TOPOLOGY} @ ${TARGET_RATE} req/s\n`;
out += ` Target URLs: ${TARGET_URLS.join(", ")}\n`;
out += `${"=".repeat(60)}\n\n`;
const m = data.metrics;
if (m.js_exec_count) {
out += ` JS Executions: ${m.js_exec_count.values.count}\n`;
}
if (m.js_exec_success) {
out += ` Success Rate: ${(m.js_exec_success.values.rate * 100).toFixed(1)}%\n`;
}
if (m.iterations) {
out += ` Iterations/sec: ${m.iterations.values.rate.toFixed(1)}\n`;
}
if (m.http_reqs) {
out += ` HTTP Reqs/sec: ${m.http_reqs.values.rate.toFixed(1)}\n`;
}
if (m.js_exec_duration) {
const d = m.js_exec_duration.values;
out += ` Exec Duration:\n`;
out += ` avg: ${safeFixed(d.avg, 2)} ms\n`;
out += ` p50: ${safeFixed(d["p(50)"], 2)} ms\n`;
out += ` p95: ${safeFixed(d["p(95)"], 2)} ms\n`;
out += ` p99: ${safeFixed(d["p(99)"], 2)} ms\n`;
out += ` max: ${safeFixed(d.max, 2)} ms\n`;
}
if (m.dropped_iterations) {
out += ` Dropped Iterations: ${m.dropped_iterations.values.count}\n`;
}
if (m.vus_max) {
out += ` Max VUs Used: ${m.vus_max.values.max}\n`;
}
out += `\n${"=".repeat(60)}\n`;
return out;
}
