CODEWITHSUNDEEP
node.jsamazon-web-servicesamazon-s3aws-lambda
Stan Luo
Stan Luo

Reputation: 3889

Create thumbnails using AWS S3 & Lambda and then load them

I'm building a react webapp which allows users to upload a picture and then render the thumbnail, just like facebook chat. But I'm not sure what's the best practice to solve the uploading-resizing-generatingThumbnail time gap before I can render them.

The workflow is like:

1) User uploads a picture to S3, stored in bucket1

2) Lambda function invoked, getting the newly uploaded picture and do the resizing work, then store thumbnail in bucket2

3) Thumbnail rendered in browser(client-side). Here it's a bit tricky - I just hardcode the img url because it's predictable, however, it takes a while before available(generating process).

But I don't know how to let lambda notifies the browser when a thumbnail successfully generated and ready to render. In production it might be lambda tells node server first, and then node server tells the client; but in developing mode, it seems impossible as I'm running an express server on my own laptop. Should lambda do the notification in a proper way or there's other better solution?

Upvotes: 0

Views: 1312

Answers (1)

John Rotenstein
John Rotenstein

Reputation: 269111

AWS Lambda cannot "notify the browser" because it is a process that was independently triggered and has no connection with the web page request.

One option would be to code the web page to keep trying to download the image. You'd need some fancy JavaScript/node code that can check whether the image was successfully downloaded and then retry if necessary.

By the way, there are also services that can resize images on-the-fly so you don't have to create your own thumbnails:

Upvotes: 1

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