Dealing with errors while processing multiple asynchronous requests simultaneously

Question

Dealing with errors while processing multiple asynchronous requests simultaneously

I am dealing with 6 asynchronous requests. The problem I'm facing is that if one of them encounters an error and returns a 404 status code, the other requests stop functioning as well. I have implemented the use of async.parallel to handle these requests, but unfortunately, I haven't been able to get it to work properly.

Below is the snippet of my code:

    async.parallel({
      request1: async (callback) => {
        const [err, result] = await to(this.$store.dispatch('myAction1', {
          id: this.$route.params.id,
        }));
        callback(err, result);
      },
      // Code for request2 to request6 omitted for brevity
      
    }, (err, results) => {
      if (err) {
        // Display an error message when any request fails
      }
      // Perform actions when all requests are successful and hide the page loader.
      this.hidePageLoader();
    });

The issue is that even if one of the requests returns a 404 error, the page loader still shows up. My goal is to either pass a failed request as null in the results object or return the other results without including the failed request in the results object. How can I achieve this correctly?

javascript ajax asynchronous vue.js request

Answer 1

Answer №1

To ensure that the remaining tasks can continue processing even if one of them fails, it is important to store the tasks in an array where each task is wrapped with async.reflect. Then, set this array of tasks as the first argument for async.parallel.

Here's an example:

async.parallel([
 async.reflect((callback) => {
   return callback(null, "one");
 }),
 async.reflect((callback) => {
   return callback("error");
 }),
 // additional tasks
], function(error, results) {
  if(error)
    return cb(error)

  // results[0].value ->> "one"
  // results[1].error ->> "error"

  return cb(results)
})

Source: Async Documentation utils >> reflect

Answer 2

To ensure that the remaining tasks can continue processing even if one of them fails, it is important to store the tasks in an array where each task is wrapped with async.reflect. Then, set this array of tasks as the first argument for async.parallel.

Here's an example:

async.parallel([
 async.reflect((callback) => {
   return callback(null, "one");
 }),
 async.reflect((callback) => {
   return callback("error");
 }),
 // additional tasks
], function(error, results) {
  if(error)
    return cb(error)

  // results[0].value ->> "one"
  // results[1].error ->> "error"

  return cb(results)
})

Source: Async Documentation utils >> reflect

Dealing with errors while processing multiple asynchronous requests simultaneously

Answer №1

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