Golang Server Timeout - go

Question

I have a very simple go server:
package main
import(
"net/http"
"fmt"
"log"
)
func test(w http.ResponseWriter, r *http.Request){
fmt.Println("No bid")
http.Error(w, "NoBid", 204)
}
func main() {
http.HandleFunc("/test/bid", test)
http.ListenAndServe(":8080", nil)
log.Println("Done serving")
}
I then run the apache benchmark tool:
ab -c 50 -n 50000 -p post.txt http://127.0.0.1:8080/test/bid
The Server runs and responds to about 15000 requests and then times out. I was wondering why this happens and if there is something I can do about this.

Answer 1

If you running in Linux, Maybe too many open files, so it can't create connection, You need change system config to support more connections.
For example,
edit /etc/security/limits.conf add
* soft nofile 100000
* soft nofile 100000
To open more file.
edit /etc/sysctl.conf
# use more port
net.ipv4.ip_local_port_range = 1024 65000
# keep alive timeout
net.ipv4.tcp_keepalive_time = 300
# allow reuse
net.ipv4.tcp_tw_reuse = 1
# quick recovery
net.ipv4.tcp_tw_recycle = 1

Answer 2

I tried to replicate your problem on my linux amd64 laptop with no success - it worked fine even with
ab -c 200 -n 500000 -p post.txt http://127.0.0.1:8080/test/bid
There were about 28,000 sockets open though which may be bumping a limit on your system.
A more real world test might be to turn keepalives on which maxes out at 400 sockets
ab -k -c 200 -n 500000 -p post.txt http://127.0.0.1:8080/test/bid
The result for this was
Server Software:
Server Hostname: 127.0.0.1
Server Port: 8080
Document Path: /test/bid
Document Length: 6 bytes
Concurrency Level: 200
Time taken for tests: 33.807 seconds
Complete requests: 500000
Failed requests: 0
Write errors: 0
Keep-Alive requests: 500000
Total transferred: 77000000 bytes
Total body sent: 221500000
HTML transferred: 3000000 bytes
Requests per second: 14790.04 [#/sec] (mean)
Time per request: 13.523 [ms] (mean)
Time per request: 0.068 [ms] (mean, across all concurrent requests)
Transfer rate: 2224.28 [Kbytes/sec] received
6398.43 kb/s sent
8622.71 kb/s total
Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 0 0.1 0 11
Processing: 0 14 5.2 13 42
Waiting: 0 14 5.2 13 42
Total: 0 14 5.2 13 42
Percentage of the requests served within a certain time (ms)
50% 13
66% 16
75% 17
80% 18
90% 20
95% 21
98% 24
99% 27
100% 42 (longest request)
I suggest you try ab with -k and take a look at tuning your system for lots of open sockets