Benchmarking in Node.js vs Deno: A Comprehensive Comparison

In the ever-evolving landscape of JavaScript runtime environments, Node.js and Deno stand out as powerful platforms for building server-side applications. While both share similarities, their approaches to performance measurement and benchmarking differ significantly. Let's dive deep into the benchmarking capabilities of these two runtimes.

The Need for Benchmarking

Performance matters. Whether you're building a high-traffic web service, a complex backend application, or just exploring the limits of your code, understanding how different implementations perform is crucial. Benchmarking helps developers:

• Identify performance bottlenecks
• Compare different implementation strategies
• Make informed architectural decisions
• Optimize critical code paths

Node.js: Custom Benchmarking Solution

In Node.js, there's no built-in benchmarking framework, which leads developers to create custom solutions. The provided example demonstrates a sophisticated approach to benchmarking:

bench.js

class Benchmark {
  constructor(name, fn, options = {}) {
    this.name = name;
    this.fn = fn;
    this.options = options;
    this.results = [];
  }

  async run() {
    const { async = false, iterations = 1000 } = this.options;
    const results = [];

    // Warmup
    for (let i = 0; i < 10; i++) {
      async ? await this.fn() : this.fn();
    }

    // Main benchmark
    for (let i = 0; i < iterations; i++) {
      const start = process.hrtime.bigint();
      async ? await this.fn() : this.fn();
      const end = process.hrtime.bigint();
      results.push(Number(end - start)); // Nanoseconds
    }

    // Sort results to calculate metrics
    results.sort((a, b) => a - b);
    this.results = {
      avg: results.reduce((sum, time) => sum + time, 0) / iterations,
      min: results[0],
      max: results[results.length - 1],
      p75: results[Math.ceil(iterations * 0.75) - 1],
      p99: results[Math.ceil(iterations * 0.99) - 1],
      p995: results[Math.ceil(iterations * 0.995) - 1],
      iterPerSec: Math.round(
        1e9 / (results.reduce((sum, time) => sum + time, 0) / iterations)
      ),
    };
  }

  getReportObject() {
    const { avg, min, max, p75, p99, p995, iterPerSec } = this.results;
    return {
      Benchmark: this.name,
      "time/iter (avg)": `${(avg / 1e3).toFixed(1)} ns`,
      "iter/s": iterPerSec,
      "(min … max)": `${(min / 1e3).toFixed(1)} ns … ${(max / 1e3).toFixed(
        1
      )} ns`,
      p75: `${(p75 / 1e3).toFixed(1)} ns`,
      p99: `${(p99 / 1e3).toFixed(1)} ns`,
      p995: `${(p995 / 1e3).toFixed(1)} ns`,
    };
  }
}

class BenchmarkSuite {
  constructor() {
    this.benchmarks = [];
  }

  add(name, fn, options = {}) {
    const benchmark = new Benchmark(name, fn, options);
    this.benchmarks.push(benchmark);
  }

  async run() {
    const reports = [];

    for (const benchmark of this.benchmarks) {
      await benchmark.run();
      reports.push(benchmark.getReportObject());
    }

    console.log(`\nBenchmark Results:\n`);
    console.table(reports);

    // Optionally, add summaries for grouped benchmarks
    this.printSummary();
  }

  printSummary() {
    const groups = this.benchmarks.reduce((acc, benchmark) => {
      const group = benchmark.options.group;
      if (group) {
        if (!acc[group]) acc[group] = [];
        acc[group].push(benchmark);
      }
      return acc;
    }, {});

    for (const [group, benchmarks] of Object.entries(groups)) {
      console.log(`\nGroup Summary: ${group}`);
      const baseline = benchmarks.find((b) => b.options.baseline);
      if (baseline) {
        for (const benchmark of benchmarks) {
          if (benchmark !== baseline) {
            const factor = (
              baseline.results.avg / benchmark.results.avg
            ).toFixed(2);
            console.log(
              `  ${baseline.name} is ${factor}x faster than ${benchmark.name}`
            );
          }
        }
      }
    }
  }
}

const suite = new BenchmarkSuite();

// Add benchmarks
suite.add("URL parsing", () => new URL("https://nodejs.org"));
suite.add(
  "Async method",
  async () => await crypto.subtle.digest("SHA-256", new Uint8Array([1, 2, 3])),
  { async: true }
);
suite.add("Long form", () => new URL("https://nodejs.org"));
suite.add("Date.now()", () => Date.now(), { group: "timing", baseline: true });
suite.add("performance.now()", () => performance.now(), { group: "timing" });

// Run benchmarks
suite.run();

node bench.js

Key Features of Node.js Benchmarking Approach:

• Completely custom implementation
• Detailed performance metrics
• Support for both sync and async functions
• Warmup phase to mitigate initial performance variations
• Comprehensive statistical analysis (avg, min, max, percentiles)
• Group-based comparisons
• Manual iteration and result collection

Deno: Built-in Benchmarking

Deno takes a different approach with its built-in Deno.bench() method:

bench.ts

Deno.bench("URL parsing", () => {
  new URL("https://deno.land");
});
Deno.bench("Async method", async () => {
  await crypto.subtle.digest("SHA-256", new Uint8Array([1, 2, 3]));
});
Deno.bench({
  name: "Long form",
  fn: () => {
    new URL("https://deno.land");
  },
});
Deno.bench({
  name: "Date.now()",
  group: "timing",
  baseline: true,
  fn: () => {
    Date.now();
  },
});

Deno.bench({
  name: "performance.now()",
  group: "timing",
  fn: () => {
    performance.now();
  },
});

deno bench bench.ts

Advantages of Deno's Approach:

• Native support
• Simpler syntax
• Integrated with Deno's testing framework
• Less boilerplate code
• Automatically handles iteration and reporting

Comparative Analysis

Pros of Node.js Custom Benchmarking:

• Extreme flexibility
• Detailed control over benchmark process
• Ability to add custom metrics
• Works across different Node.js versions
• Can be extended for complex scenarios

Pros of Deno Built-in Benchmarking:

• Simplicity
• Native integration
• Less code to maintain
• Standardized approach
• Automatic optimization and reporting

When to Use Each Approach

Use Node.js Custom Benchmarking When:

• You need extremely detailed performance insights
• Your benchmarks have complex requirements
• You want full control over the measurement process
• Working with older Node.js versions

Use Deno Benchmarking When:

• You want a quick, straightforward performance check
• Using the latest Deno runtime
• Need minimal setup
• Prefer built-in, standardized tools

Performance Considerations

Both approaches use high-resolution timing methods:

• Node.js: process.hrtime.bigint()
• Deno: Internal high-resolution timer

The key difference lies in the level of detail and manual intervention required.

Conclusion

While Node.js requires developers to build their own comprehensive benchmarking solutions, Deno provides a batteries-included approach. Your choice depends on your specific needs, project complexity, and personal preference.

The future of JavaScript runtimes is exciting, with both Node.js and Deno pushing the boundaries of performance measurement and optimization.

Pro Tips

• Always run benchmarks multiple times
• Consider external factors like system load
• Use percentile metrics for more robust performance evaluation
• Don't optimize prematurely

Happy benchmarking! 🚀📊