Microservices & Scaling

Preview — 3 of 10 questions

What problem does this pipeline have?

javascript

const fs = require("fs");
const { Transform } = require("stream");

const input = fs.createReadStream("large-file.txt");

// Custom transform: uppercase
const uppercase = new Transform({
  transform(chunk, encoding, callback) {
    this.push(chunk.toString().toUpperCase());
    callback();
  }
});

const output = fs.createWriteStream("output.txt");

input.pipe(uppercase).pipe(output);

ANo problem; code is correct.

BStreams are deprecated.

CNo backpressure handling; might cause memory issues.

DOnly works for small files.

When should you use Worker Threads vs Child Processes?

AWorker Threads for everything.

BNo difference between them.

CChild Processes only for file I/O.

DChild Processes: CPU-heavy tasks, isolate failures. Worker Threads: CPU-heavy tasks, shared memory.

What advanced error recovery patterns exist?

AJust log errors and continue.

BCircuit breaker, retry with exponential backoff, graceful degradation.

CErrors should never happen.

DRestart entire application.

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