負載測試

由於 Socket.IO 有其自己的通訊協定，包括握手、心跳和自訂封包編碼，因此負載測試 Socket.IO 伺服器的最簡單方法就是使用 Socket.IO 用戶端程式庫並建立大量的用戶端。

有兩種經典的解決方案可以做到這一點

• 使用 Artillery
• 或 手動管理用戶端

Artillery

Artillery 是用於負載測試應用程式的絕佳工具。它允許建立連線、傳送事件和檢查確認。

文件可以在這裡找到。

重要事項：預設安裝附帶 v2 用戶端，這與 v3/v4 伺服器不相容。您需要為此安裝自訂引擎：https://github.com/ptejada/artillery-engine-socketio-v3

安裝

$ npm install artillery artillery-engine-socketio-v3

範例情境

# my-scenario.yml
config:
  target: "http://localhost:3000"
  phases:
    - duration: 60
      arrivalRate: 10
  engines:
   socketio-v3: {}

scenarios:
  - name: My sample scenario
    engine: socketio-v3
    flow:
      # wait for the WebSocket upgrade (optional)
      - think: 1

      # basic emit
      - emit:
          channel: "hello"
          data: "world"

      # emit an object
      - emit:
          channel: "hello"
          data:
            id: 42
            status: "in progress"
            tags:
              - "tag1"
              - "tag2"

      # emit in a custom namespace
      - namespace: "/my-namespace"
        emit:
          channel: "hello"
          data: "world"

      # emit with acknowledgement
      - emit:
          channel: "ping"
        acknowledge:
          match:
            value: "pong"

      # do nothing for 30 seconds then disconnect
      - think: 30

執行此情境

$ npx artillery run my-scenario.yml

Artillery 也隨附許多很棒的功能，例如 將指標發布到各種端點 或 從 AWS 執行測試 的能力。

它唯一的限制是您無法輕易測試伺服器到用戶端的事件，因為 Artillery DSL 更適合傳統的用戶端到伺服器通訊。這讓我們進入 下一部分。

手動建立用戶端

以下是建立一千個 Socket.IO 用戶端並監控每秒接收封包數量的基本腳本

const { io } = require("socket.io-client");

const URL = process.env.URL || "http://localhost:3000";
const MAX_CLIENTS = 1000;
const POLLING_PERCENTAGE = 0.05;
const CLIENT_CREATION_INTERVAL_IN_MS = 10;
const EMIT_INTERVAL_IN_MS = 1000;

let clientCount = 0;
let lastReport = new Date().getTime();
let packetsSinceLastReport = 0;

const createClient = () => {
  // for demonstration purposes, some clients stay stuck in HTTP long-polling
  const transports =
    Math.random() < POLLING_PERCENTAGE ? ["polling"] : ["polling", "websocket"];

  const socket = io(URL, {
    transports,
  });

  setInterval(() => {
    socket.emit("client to server event");
  }, EMIT_INTERVAL_IN_MS);

  socket.on("server to client event", () => {
    packetsSinceLastReport++;
  });

  socket.on("disconnect", (reason) => {
    console.log(`disconnect due to ${reason}`);
  });

  if (++clientCount < MAX_CLIENTS) {
    setTimeout(createClient, CLIENT_CREATION_INTERVAL_IN_MS);
  }
};

createClient();

const printReport = () => {
  const now = new Date().getTime();
  const durationSinceLastReport = (now - lastReport) / 1000;
  const packetsPerSeconds = (
    packetsSinceLastReport / durationSinceLastReport
  ).toFixed(2);

  console.log(
    `client count: ${clientCount} ; average packets received per second: ${packetsPerSeconds}`
  );

  packetsSinceLastReport = 0;
  lastReport = now;
};

setInterval(printReport, 5000);

您可以將它用作載入測試您自己的應用程式的起點。