Golang concurrent HTTP request

Question

I wanted to test the performance of concurrent http request in Go against node.js:

package main
import (
 "fmt"
 "time"
 "strconv"
 "net/http"
)
var responseCounter = 0
var requestCounter = 0
var count=0
var ch = make(chan int)
func sendRequest(){
 go func() {
 requestCounter++
 url := "https://www.google.co.in/#q=search_" +strconv.Itoa(requestCounter)
 resp, err := http.Get(url)
 if err != nil {
 fmt.Printf("\nError",err)
 }
 defer resp.Body.Close()
 count++
 ch <- count
 sendRequest()
 }()
}
func main() {
 for i := 1; i<100; i++{
 sendRequest()
 }
 for {
 select {
 case r := <-ch:
 fmt.Printf("\nChannel ",r)
 case <-time.After(50 * time.Millisecond):
 //sendRequest()
 }
 }
}

When I run this code the CPU usage goes very high (around 90%). Is there something wrong with this code? Have I used the Goroutines correctly?

• akonsu: but you start infinitely many goroutines in your sendRequest, no?
• Sarita: I did so because I wanted the requests to be continuous. So when one http request is complete I made another request by calling sendRequest(). Is there a better way to achieve this?
• akonsu: try to wait for the goroutine to finish and then start another one. I do not know what is going on...
• Dave C: So many data races!! (go {build,install,run,test} -race is your friend).

Answer 1

Inside SendRequst you are calling SendRequest again, which will make your stack full of recursive calls.