Mashup

Description

We want to build a mash-up service that takes two web service sources that return an integer, "Source A" and "Source B", fetches the results from them, adds them together, and then returns the final result.

For example, if "Source A" returns 45, and "Source B" returns 466, we want our final web service to return 511, with the exact URL of /result with JSON structure:

$ curl http://127.0.0.1:12000/result
{
   "final_result":511
}

Getting Started

$ go run main.go

Starts an example "Source A" and "Source B", as well as a hard coded example Mashup service.

• Source A
• Source B
• Example Mashup

Use CURL to examine any of the example outputs:

$ curl http://127.0.0.1:10000/value
{
  "Value": 45
}

Problems (and what to look out for)

• What if "Source A" or "Source B" stop working? Make sure your mashup service gracefully handles if one (or both) services stop responding. "Gracefully handles" would be return an appropriate HTTP response code, such as HTTP/500.

• Bad Data Both "Source A" and "Source B" may malfunction -- returning unexpected data. Make sure that you handle data in a format you don't expect.

• Delays Perhaps "Source A" returns quickly, but "Source B" never returns. Make sure that a timeouts are handled correctly. (with a reasonable HTTP response code)

Extra Bonus Ideas

• Can the results for "Source A" and "Source B" be gathered in parallel?

• Given that "Source A" and "Source B" might take a long time to return, how would you implement a cache?