Couchbase eventing mechanism instead of queues

[randytpierce]

It is possible to use Couchbase eventing instead of message queues. Refer to eventing

A possible flow is...

1. The MATS process_scorecard server side function inserts a new scorecard document into the Scorecard collection
2. An associated Couchbase eventing function detects the new entry
3. The eventing function uses curl to send an http request to the calculate service
4. The calculate service reads the scorecard and begins to process it
5. The calculate service makes updates to the scorecard object
6. With each update an eventing function detects the update (as opposed to new) and uses curl to send an http request to the scorecard app to notify it to update its mongo instance with the new data from couchbase
7. The updated mongo is feeding a reactive variable in the scorecard display (if the scorecard is being viewed) which causes the display to updated dynamically.

This is pretty simple, really. It requires two rest api functions. In the MATS app the rest service endpoint is easily defined in matsmethods (we already have picker routes set up there). In the calculate service we implement a rest service endpoint in go.

[randytpierce]

Should refer to the sequence diagram here (paste it into the online renderer at plantUml.com)