Hi,
I am working on a SAAS based project which is built using REST API and can have multiple merchant accounts. We need to run crons for every merchant per 10 mins. The cron urls are our server’s own apis. So I used Golang’s net/http package to fulfil this requirement.
Errors I am getting:
http: Accept error: accept tcp [::]:8080: accept4: too many open files; retrying in 1s
and
connection() error occured during connection handshake: dial tcp IP:27017: socket: too many open files.
What I have tried:
I have tried connection: close header and removing defer and call explicit req.Body.Close() and reuse http client to avoid connection overlimit.
Have a look at the code:
package main
import (
"gopkg.in/robfig/cron.v3"
)
func main() {
RunCron()
}
func RunCron() {
c := cron.New()
c.AddFunc("@every 0h10m0s", SendMsg)
c.Start()
}
func SendMsg() {
RunCronBatch()
}
func RunCronBatch() {
businessNames := []string{"bsName1", "bsName2","bsName3","bsName4"}
client := &http.Client{}
for _, businessName := range businessNames {
url := "http://" + businessName + ".maim-domain.com"
go func(client *http.Client, url string) {
CallHttpRqstScheduler(client, "GET", url, false)
}(client, url)
}
}
func CallHttpRqstScheduler(client *http.Client, method, url string, checkResp bool, body ...io.Reader) (error, interface{}) {
var reqBody io.Reader
if len(body) > 0 {
reqBody = body[0]
} else {
reqBody = nil
}
req, err := http.NewRequest(method, url, reqBody)
if err != nil {
fmt.Print(err.Error())
return err, nil
}
req.Header.Set("Connection", "close")
if method == "POST" {
req.Header.Add("Content-Type", "application/json")
}
resp, err := client.Do(req)
if err != nil {
fmt.Print(err.Error())
return err, nil
}
if checkResp {
bodyBytes, err := ioutil.ReadAll(resp.Body)
if err != nil {
fmt.Print(err.Error())
req.Close = true
resp.Body.Close()
return err, nil
}
var response APIResponseObj
err = json.Unmarshal(bodyBytes, &response)
if err != nil {
fmt.Print(err.Error())
req.Close = true
resp.Body.Close()
return err, nil
}
req.Close = true
resp.Body.Close()
return nil, response.Response.Data
}
req.Close = true
resp.Body.Close()
return nil, nil
}
But this structure still giving me the above mentioned errors.
History:
Before implementing this structure I have also used curl along with sh command. But that structure was also eating up resources and hence came across resource temporarily unavailable.
package main
func main() {
businessNames := []string{"bsName1", "bsName2","bsName3","bsName4"}
for _, businessName := range businessNames {
url := "http://" + businessName + ".main-domain.com"
command := "curl '"+url+"'"
ExecuteCommand(command)
}
}
func ExecuteCommand(command string) error {
cmd := exec.Command("sh", "-c", command)
var out bytes.Buffer
var stderr bytes.Buffer
cmd.Stdout = &out
cmd.Stderr = &stderr
err := cmd.Run()
if err != nil {
fmt.Println(fmt.Sprint(err) + ": " + stderr.String())
return err
}
fmt.Println("Result: " + out.String())
return nil
}
Can someone guide me that in the http approach what I am doing wrong or missing something here.