We recently started encountering a strange error in a process that was working fine earlier. In one of our lambda functions, we upload a file from ephemeral storage to an S3 bucket.

await s3Client.send(
  new PutObjectCommand({
    Bucket: bucket,
    Key: `${id}.mp4`,
    Body: createReadStream(outputFile),
    ContentType: 'video/mp4',
    Tagging: 'test=true',
  }),
);

The call is failing with the error

ERROR   Invoke Error    
{
    "errorType": "TimeoutError",
    "errorMessage": "socket hang up",
    "code": "ECONNRESET",
    "name": "TimeoutError",
    "stack": [
        "TimeoutError: socket hang up",
        "    at connResetException (node:internal/errors:720:14)",
        "    at TLSSocket.socketOnEnd (node:_http_client:525:23)",
        "    at TLSSocket.emit (node:events:529:35)",
        "    at endReadableNT (node:internal/streams/readable:1400:12)",
        "    at process.processTicksAndRejections (node:internal/process/task_queues:82:21)"
    ]
}

The file being transferred was around 50 MB in size but up until now we had never faced any issue with much bigger files as well.

I tried looking up this error but did not find any definitive solution or the root cause of it. As a trial, we switched to SDK version 2 and used the putObject command like this

await s3ClientV2.putObject({
  Bucket: bucket,
  Key: `${id}.mp4`,
  Body: createReadStream(outputFile),
  ContentType: 'video/mp4',
  Tagging: 'test=true',
}).promise();

Which worked like a charm. I don’t understand if it is a bug in AWS SDK v3 or something missing at our end but this used to work perfectly earlier and is breaking now.