Error: stream.push() after EOF

[jotto]

Explanation

I'm intermittently getting these stream.push errors on an HTTP server, which seem to terminate the Node process, even with a process.on("unhandledRejection"). I assume the error is happening because the HTTP client is disconnecting before the stream finishes, but why can't I seem to capture these errors and/or prevent Node from terminating?

Possible solution?

Could it be as simple as adding try/catch around the .push call in readStream?

streaming-cache/lib/readStream.js

Line 40 in 90121ff

this.push(this._object.slice(this._offset, this._offset + size));

Error message/stack

Note, the line numbers in this stack trace are a little off because I'm using the forked code from #14

Error: stream.push() after EOF
    at readableAddChunk (_stream_readable.js:240:30)
    at ReadStream.Readable.push (_stream_readable.js:208:10)
    at ReadStream._push (/app/node_modules/streaming-cache/lib/readStream.js:44:14)
    at ReadStream.setBuffer (/app/node_modules/streaming-cache/lib/readStream.js:19:10)
    at EventEmitter.<anonymous> (/app/node_modules/streaming-cache/index.js:105:16)
    at emitOne (events.js:116:13)
    at EventEmitter.emit (events.js:211:7)
    at Duplex.<anonymous> (/app/node_modules/streaming-cache/index.js:204:28)
    at emitNone (events.js:111:20)
    at Duplex.emit (events.js:208:7)
    at finishMaybe (_stream_writable.js:614:14)
    at endWritable (_stream_writable.js:622:3)
    at Duplex.Writable.end (_stream_writable.js:573:5)
    at ReadStream.onend (_stream_readable.js:595:10)
    at Object.onceWrapper (events.js:313:30)
    at emitNone (events.js:111:20)
    at ReadStream.emit (events.js:208:7)
    at endReadableNT (_stream_readable.js:1064:12)
    at _combinedTickCallback (internal/process/next_tick.js:138:11)
    at process._tickDomainCallback (internal/process/next_tick.js:218:9)

Code looks like:

app.get('/', (req, res) => {
  const streamingCached = streamingCache.get("some-cache-key");

  if (streamingCached) {
    return streamingCached
      .pipe(res)
      .on("error", console.error)
  }
})

[jotto]

I deployed the try/catch and it seems to have addressed the problem: https://github.com/jotto/streaming-cache/commit/aa9f63c27889d6cbcb62f46d627fc11de110bb6e

[LaurentZuijdwijk]

@jotto, thanks for your work on this and sorry for the late reply.
It seems like this issue is similar jeffbski/redis-rstream#4 and their solution was to use a try/catch. There might be a small performance price to pay, but it shouldn't be too bad.

I would suggest using 'uncaughtException' in your code. 'unhandledRejection' is only used for promises.

The following might help as well. Errors are not automatically forwarded in a stream.

  if (streamingCached) {
    streamingCached    
     .on("error", console.error)
     return streamingCached
      .pipe(res)
      .on("error", console.error)
  }

[LaurentZuijdwijk]

Will close this issue. A new version has been pushed to NPM.