Asynchronous Calls
The system executes web actions or REST APIs as synchronous (blocking) calls and gives them 60 seconds to complete their work. Actions that need more time can use asynchronous (async) calls, and use up to 180 minutes.
Since web actions and APIs are always executed synchronously, you need to separate work that needs more time (the async call) from work that can be done in under a minute using synchronous calls. There are two ways to do this:
Option 1: web action that calls the actual action async
First, we create an action. This one, worker
, uses a setTimeout function to simulate long-running code.
Copied to your clipboard// worker.jsfunction main(args) {return new Promise(function(resolve, reject) {setTimeout(function() {var result = {statusCode: 200,body: {payload: 'Hello from the long running job!'}};resolve(result);}, 100000);});}exports.main = main;
Next we set the -t
flag to change the default timeout. If we know that an action needs about 100,000 milliseconds to complete, we can set it to 120,000 milliseconds (2 minutes) to be sure it completes its work before timeout.
Copied to your clipboardaio rt:action:create my-worker worker.js -t 120000
Then we build a web action that calls the worker
action we created above. We can simplify this step by using the OpenWhisk Node module. Since it's part of I/O Runtime Node.js environment, we don't need to pack the module with our code.
Copied to your clipboard//web-action.jslet openwhisk = require("openwhisk");// This returns the activation ID of the action that it calledfunction main(args) {let ow = openwhisk();return ow.actions.invoke({name: 'worker', // the name of the action to invokeblocking: false, // this is the flag that instructs to execute the worker asynchronousresult: false,params: args});}exports.main = main;
Now we can create the web action:
Copied to your clipboardaio rt:action:create test web-action.js --web true
Invoking this web action will deliver the ActivationId for the worker
action, which can be used to retrieve the result.
In this sample invocation, the .json
extension appended to the URI instructs the system to return the result as JSON:
Copied to your clipboardcurl https://adobeioruntime.net/api/v1/web/YOUR-NAMESPACE-HERE/default/test.json{"activationId": "0123456789"}
Option 2: using triggers and rules
Another way to set up an asynchronous call is to create a trigger and a rule to call the action. This will work only for calls using a POST method; if you need a GET, use Option 1.
Here is the code, using the my-worker
action from above:
Copied to your clipboard// First, you create a triggeraio rt:trigger:create my-worker-trigger//Then, you create the ruleaio rt:rule:create async-rule my-worker-trigger my-worker
Now when the trigger my-worker-trigger
is executed, it will in turn execute the my-worker
action. Note the authentication header: it must match the authentication as used by the namespace where the actions, triggers, and rules were created.
Copied to your clipboardcurl https://adobeioruntime.net/api/v1/namespaces/_/triggers/my-worker-trigger -X POST -H "Authorization: Basic NAMESPACE AUTHORIZATION"
To find the URI and the authorization for a trigger or secured web action, add -v
(verbose) to the command to get it:
Copied to your clipboardaio rt:trigger:get my-worker-trigger -v
Retrieval of the action activationId (and not the trigger activationId) is trickier than in Option 1. Use the trigger activationId to retrieve the logs, which will contain the action activationId you can use to read the result.
Next steps
Learn about Triggers and Rules.
Return to Guides Index.