How can one do parallel actions in OpenWhisk?

Question

I have two actions (each one does a different REST call to a service to collect some data), and I want to create a meta-Action which essentially triggers the two actions and aggregates the results.

I am just getting started with OpenWhisk, And I pretty much know how I would do this in the given language I am using to implement actions, but I am curious what the appropriate OpenWhisk way to do this might be?

Answer 1

If you want to aggregate the results, there is no other way currently than the one described by you:

Create a new action, fire the two actions (blocking=true) and merge the results.

The openwhisk module on npm makes that extra-simple, as you can invoke an array of actions there:

var openwhisk = require("openwhisk")
function main(params) {
    var ow = openwhisk()
    return ow.actions.invoke([
        {name: "action1", blocking: true}, 
        {name: "action2", blocking: true}
    ]).then(([result1, result2]) => { /* do something */ });
}

Invoking the actions blockingly, makes their results available in the response vs. not using blocking where you'll only get an activation id to get the results in an asynchronous fashion.