Using AWS and Bit.ly to Eliminate Server State | Hacker News Reader

Using AWS and Bit.ly to Eliminate Server State

stephenpoletto.tumblr.com

15 pointsspoletto12 comments

It seems like it might be simpler both for the dev and the user to just send an SMS with a neatly-formatted text version of the bill rather than a link to a screenshot of the bill. If it's just a couple amounts, tax, tip, and total, that seems like it would easily fit in 140 characters. The app design looks pretty nice though.

Edit: I guess maybe the advantage of this design is that you can easily send the bill for everyone at the table to everyone (probably wouldn't fit into 140 chars), which eliminates the need for the user to individually choose which contact corresponds to which column of the bill.

The images that are being sent contain the amounts, tax, subtotal, tip and total for up to 16 individual people. Here's an example: http://billr.me/J7W5uY

I wonder if he could regenerate the screenshot on the server side, or more realistically simply show the same information on a web page. Then he could put all the information that goes into the screenshot—“amounts, tax, subtotal, top and total for up to 16 individual people” doesn’t sound like that much data—into a billr.me URL, and shorten that with bit.ly. That would save some money because no screenshots would need to be stored on S3.

I don't understand why bit.ly is involved at all... basically just to generate a unique short key?

If you implemented your own shout url generation you could just name the image with the short url and stop giving bit.ly that kind of insight into your operation.

Nice way to briefly hit the front page of Hacker News though, and the app looks nice!

I'm basically using Bit.ly as a key-value store and short URL generator. The Billr server doesn't maintain a database.

I guess I didn't explain myself clearly... if you shortened the url yourself (I'm sure you can find a good implementation of this), why not name the S3 image exactly the same as the short url?

In the example you gave elsewhere, the image would be http://billr.s3.amazonaws.com/J7W5uY instead of http://billr.s3.amazonaws.com/01C03E08-4CFD-4709-87C9-BB60FD... - so bit.ly wouldn't be needed.

The suggestion elsewhere in this discussion to encode the entire bill in the url is probably the optimal solution though. With a bit of caching it's probably the cheapest you could run your system (sans S3).

So he is using bitly as a key value store.

other than url shortening, does anyone offer this as a service? a key value only online service?

You can just use any of the online DB REST interfaces.

MongoLab has a nice one http://support.mongolab.com/entries/20433053-rest-api-for-mo...

That will return a json object as the value.

Amazon SimpleDB: http://aws.amazon.com/simpledb/

Combining these four elements has allowed me to upload and serve images from the billr.me domain without maintaining a database. I’m hosting on https://www.nearlyfreespeech.net/ for pennies per month and never need to do any server maintenance.

I dont think he is counting the cost of hosting on S3. :)

S3 is pretty cheap as well. $0.125 per GB of storage. Considering the images are ~80KB on average, S3 hosting is also just pennies per month. :)

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