Versioning & Streaming — Series 3

Preview — 3 of 10 questions

What distinguishes this from header versioning?

javascript

app.enableVersioning({ type: VersioningType.MEDIA_TYPE, key: 'v=' });
// client: Accept: application/json;v=2

AIt versions the transport rather than the resource

BThe version travels inside the standard Accept header as a media-type parameter, so it participates in content negotiation and in Vary-based caching without introducing a custom header that proxies may strip or ignore

CIt allows only integer versions, unlike the other strategies

DIt applies to responses only; requests are matched by URI

What sequence retires v1 safely?

javascript

app.enableVersioning({ type: VersioningType.URI, defaultVersion: '1' });
// goal: make v2 the default, then remove v1

AChange defaultVersion to '2' and delete the v1 controllers in the same deploy

BRemove the v1 routes first; clients still calling them will retry against v2

CKeep both versions forever, since a removed version breaks unknown clients

DShip v2 alongside v1; announce the retirement with Deprecation/Sunset on v1 responses; watch traffic per version until v1 calls approach zero; switch defaultVersion to '2'; then remove v1 in a later deploy

Why does this struggle with large files, and what changes?

javascript

@Post('avatar')
@UseInterceptors(FileInterceptor('file'))
upload(@UploadedFile() file: Express.Multer.File) {
  return this.s3.putObject({ Body: file.buffer, /* ... */ });
}

AThe interceptor buffers the whole file — in memory with the default storage, or to a temporary file on disk — before the handler runs, so peak usage scales with file size times concurrency; streaming the request body straight to storage keeps memory flat, at the cost of giving up the convenience of a fully-received file object

BMulter rejects files above 1 MB unless limits is raised

CThe AWS SDK cannot accept a buffer, only a stream

DThe interceptor runs after the handler, so file is undefined for large uploads

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