Difficulty Implementing Concurrent Goroutines in Website Backend

I’m currently working on a web application backend using Go (Golang) and I’m encountering difficulties with implementing concurrent goroutines effectively.

Specifically, I have a section of my code where I need to perform multiple I/O operations simultaneously, such as fetching data from multiple APIs, processing them concurrently, and then aggregating the results.

While I understand the concept of goroutines and channels in Go, I’m struggling with structuring my code to ensure proper synchronization, error handling, and efficient resource utilization.

I’ve attempted to use goroutines along with sync.WaitGroup and channels to coordinate the execution of concurrent tasks, but I’m not achieving the desired results. Sometimes, I encounter race conditions or deadlocks, and other times, the performance doesn’t improve as expected.

If anyone has experience with implementing concurrent goroutines in Go for web application backends, I would greatly appreciate some guidance or best practices to follow. Additionally, any suggestions on debugging techniques or tools to identify and resolve concurrency issues would be invaluable. Thank you in advance for your assistance!

It’s a little easier to help if you include your code.

Thank you for your response. I apologize for not including my code initially. Here’s a simplified version of the section where I’m encountering difficulties with implementing concurrent goroutines:

package main

import (
    "fmt"
    "sync"
)

func fetchDataFromAPI(apiURL string, wg *sync.WaitGroup, ch chan<- string) {
    defer wg.Done()

    // Simulating fetching data from API
    // In real scenario, this would involve making HTTP requests
    data := fmt.Sprintf("Data from API: %s", apiURL)

    // Sending data to channel
    ch <- data
}

func process(data string) string {
    // Simulating processing data
    // In real scenario, this would involve some computation
    processedData := fmt.Sprintf("Processed data: %s", data)
    return processedData
}

func main() {
    apiURLs := []string{"api1.com", "api2.com", "api3.com"}

    var wg sync.WaitGroup
    ch := make(chan string)

    for _, url := range apiURLs {
        wg.Add(1)
        go fetchDataFromAPI(url, &wg, ch)
    }

    go func() {
        wg.Wait()
        close(ch)
    }()

    for result := range ch {
        processedResult := process(result)
        fmt.Println(processedResult)
    }
}

This code attempts to fetch data from multiple APIs concurrently, process them, and then print the processed results. However, I’m encountering issues with proper synchronization and resource management.

Any advice or suggestions on how to improve this code to ensure proper concurrency, error handling, and efficient resource utilization would be greatly appreciated. :innocent: :slightly_smiling_face: Thank you!

That code seems to work for me (I added some simulated delays)

Do you see the issues with this code? I’m wondering if because you said “resource management” that the real problem needs the real API requests in order to surface?

Explain (or ideally show) what issues you’re having.

Pass error channels between goroutines to propagate errors back to the main program for handling. Alternatively, use techniques like context cancellation with cancellation channels to stop goroutines gracefully when an error occurs.