First things I notice are that you're overriding the default dialer with one that doesn't timeout, and you've commented out ReadTimeout in the client. Both of those could indefinitely hold up client connections regardless of the DoTimeout call, which just ensures that the Do function returns before the deadline.
Otherwise, I think you're going to have to instrument the code a little better to see what is holding you up. On Thursday, February 2, 2017 at 11:27:38 AM UTC-5, emarti...@gmail.com wrote: > > Thanks for the answer. > > Yes, it seems to be blocking, I just fixed it with: > http://blog.sgmansfield.com/2016/01/the-hidden-dangers-of-default-rand/ > > After that change my code is working a lil bit better but still I see a > ton of timeouts + high latency on responses. Maybe the code is locking on > another part of the code? > > El jueves, 2 de febrero de 2017, 4:09:07 (UTC-3), land...@gmail.com > escribió: >> >> func randInt(min int, max int) int { >> rand.Seed(int64(time.Now().Nanosecond())) >> return min + rand.Intn(max-min) >> } >> >> Is the culprit. the default rand locks globally for concurrent access. >> You need to create a new rand in each goroutine you want to use it in, for >> maximum speed. >> >> On Wednesday, February 1, 2017 at 8:26:07 PM UTC-6, emarti...@gmail.com >> wrote: >>> >>> Hello, >>> >>> I'm writing a POC for a future RTB platform. Basically I'm doing stress >>> tests by receiving HTTP requests and performing HTTP GET requests in the >>> background. >>> >>> Issue I face is that when i try to scale up, URLs starts to timeout. I >>> am trying to find what our bottleneck is but so far no luck (we aren't >>> running out of ephemeral ports). >>> >>> Remote URLs takes about 500ms-1000ms to respond. We are stress testing >>> it with wrk with 5000 concurrent requests. (5000 incoming requests which >>> translated into 30 remote URL requests = 150k requests) >>> >>> Here is our code: >>> >>> package main >>> >>> import ( >>> "net/http" >>> "time" >>> "runtime" >>> "io" >>> "net" >>> "github.com/valyala/fasthttp" >>> "math/rand" >>> ) >>> >>> type HttpResponse struct { >>> url string >>> response *http.Response >>> err error >>> } >>> >>> var urls = []string{ >>> //lots of urls >>> } >>> >>> >>> //func asyncHttpGets(urls []string) []*HttpResponse { >>> >>> var( >>> clients []fasthttp.Client >>> total_clients int >>> max_urls int >>> ) >>> >>> func init(){ >>> max_urls=30 >>> clients =append(clients, create_client() ) >>> } >>> >>> func create_client() fasthttp.Client{ >>> >>> return fasthttp.Client{ >>> Dial: func(addr string) (net.Conn, error) { >>> var dialer = net.Dialer{} >>> return dialer.Dial("tcp", addr) >>> }, >>> >>> MaxIdleConnDuration:30*time.Second, >>> MaxConnsPerHost:2024, >>> //ReadTimeout: 1*time.Second, >>> } >>> } >>> >>> func randInt(min int, max int) int { >>> rand.Seed(int64(time.Now().Nanosecond())) >>> return min + rand.Intn(max-min) >>> } >>> >>> >>> func asyncHttpGets(urls []string) []string{ >>> ch:=make(chan string,max_urls) >>> var responses []string >>> >>> cl:=0 >>> for i := 0; i <= max_urls; i++ { >>> url:=urls[i] >>> go func(url string) { >>> >>> req := fasthttp.AcquireRequest() >>> req.SetRequestURI(url) >>> req.Header.Add("Connection", "keep-alive") >>> resp := fasthttp.AcquireResponse() >>> clients[cl].DoTimeout(req, resp,1*time.Second) >>> >>> bodyBytes := resp.Body() >>> ch <- string(bodyBytes) >>> >>> fasthttp.ReleaseRequest(req) >>> fasthttp.ReleaseResponse(resp) >>> }(url) >>> } >>> >>> for { >>> select { >>> case r := <-ch: >>> responses = append(responses, r) >>> if len(responses) == max_urls { >>> return responses >>> } >>> } >>> } >>> return responses >>> } >>> >>> func hello(w http.ResponseWriter, r *http.Request) { >>> results := asyncHttpGets(urls) >>> for _, result := range results { >>> io.WriteString(w,"%s status: %s" + " " + result + "\n") >>> } >>> } >>> >>> >>> func main() { >>> runtime.GOMAXPROCS(0) >>> >>> server8000 := http.NewServeMux() >>> server8000.HandleFunc("/", hello) >>> http.ListenAndServe(":8001", server8000) >>> } >>> >>> >>> Any help is really appreciated. >>> >> -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
