hardLow-Level Design

What is backpressure in Node.js streams and how do you handle it?

Q: What is backpressure in Node.js streams and how do you handle it?

**TL;DR.** **Backpressure** is the mechanism that prevents a **fast producer** from overwhelming a **slow consumer**. When writable.write() returns false , its internal buffer is full — you must **stop writing** until the 'drain' event. .pipe() and pipeline() handle this automatically; manual writers must respect the return value. fast producer buffer full! <path class='d-edge' d='M324 78 H392' marker-e

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Explain the scenario where data production outpaces data consumption and how to resolve it.

streamsmemorybackpressure

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Respecting write()'s return value

function writeAll(writable, chunks, done) {
  let i = 0;
  (function next() {
    while (i < chunks.length) {
      const ok = writable.write(chunks[i++]);
      if (!ok) return writable.once('drain', next); // pause + resume
    }
    done();
  })();
}

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