Snapshot of verae-nats-cluster (optimal NATS config study)

scripts/udp-probe.mjs

@@ -0,0 +1,54 @@
+#!/usr/bin/env node
+/** UDP echo RTT. server: node udp-probe.mjs server [port]
+ *  client: node udp-probe.mjs client <host> <count> [port] [size] */
+import dgram from "node:dgram";
+
+const mode = process.argv[2] || "server";
+const port = Number(process.argv[mode === "server" ? 3 : 5] || 9999);
+
+if (mode === "server") {
+  const s = dgram.createSocket("udp4");
+  s.on("message", (msg, rinfo) => s.send(msg, rinfo.port, rinfo.address));
+  s.bind(port, "0.0.0.0", () => console.log(JSON.stringify({ mode: "udp-server", port })));
+} else {
+  const host = process.argv[3];
+  const count = Number(process.argv[4] || 1000);
+  const size = Number(process.argv[6] || 128);
+  const sock = dgram.createSocket("udp4");
+  const payload = Buffer.alloc(size, 7);
+  const samples = [];
+  let i = 0;
+  const sendOne = () => {
+    const t0 = process.hrtime.bigint();
+    const once = (msg) => {
+      sock.off("message", once);
+      samples.push(Number(process.hrtime.bigint() - t0) / 1000);
+      i += 1;
+      if (i >= count) {
+        samples.sort((a, b) => a - b);
+        const us = (n) => `${(n / 1000).toFixed(3)}ms`;
+        const pct = (p) => samples[Math.min(samples.length - 1, Math.floor((p / 100) * samples.length))];
+        const sum = samples.reduce((a, b) => a + b, 0);
+        console.log(
+          JSON.stringify({
+            mode: "udp-ping",
+            count: samples.length,
+            size,
+            host,
+            min: us(samples[0]),
+            avg: us(sum / samples.length),
+            p50: us(pct(50)),
+            p99: us(pct(99)),
+            max: us(samples[samples.length - 1]),
+            p50_us: Math.round(pct(50)),
+            p99_us: Math.round(pct(99)),
+          }),
+        );
+        sock.close();
+      } else sendOne();
+    };
+    sock.on("message", once);
+    sock.send(payload, port, host);
+  };
+  sendOne();
+}