Apachebench benchmark Results

I ran basic Apachebench benchmark load test from a separate 4th VPS at a different web host (still located in same Chicago, IL as the 3x load balanced VPS) to test Centminmod.com index page and results are below. Centminmod.com runs on 3x 512MB / 1GB Burst OpenVZ based VPSes (web1-3) load balanced via Haproxy load balancer on web3. Haproxy evenly distributed all requests across the 3x VPS servers.

Haproxy load balancer stats from Apache benchmark test on 3x Centmin Mod Nginx based web servers

Apachebench benchmark run with 500 concurrency level and 10000 requests.

ab -k -n 10000 -c 500 http://centminmod.com/index.html

This is ApacheBench, Version 2.3 <$Revision: 655654 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/

Benchmarking centminmod.com (be patient)
Completed 1000 requests
Completed 2000 requests
Completed 3000 requests
Completed 4000 requests
Completed 5000 requests
Completed 6000 requests
Completed 7000 requests
Completed 8000 requests
Completed 9000 requests
Completed 10000 requests
Finished 10000 requests


Server Software:        nginx
Server Hostname:        centminmod.com
Server Port:            80

Document Path:          /index.html
Document Length:        7818 bytes

Concurrency Level:      500
Time taken for tests:   13.909 seconds
Complete requests:      10000
Failed requests:        0
Write errors:           0
Keep-Alive requests:    0
Total transferred:      82081680 bytes
HTML transferred:       78330086 bytes
Requests per second:    718.98 [#/sec] (mean)
Time per request:       695.430 [ms] (mean)
Time per request:       1.391 [ms] (mean, across all concurrent requests)
Transfer rate:          5763.19 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:       51  270 798.5     60    9060
Processing:   106  370 416.3    225    9468
Waiting:       53  159 251.2    106    6904
Total:        158  640 897.1    319   10967

Percentage of the requests served within a certain time (ms)
  50%    319
  66%    522
  75%    612
  80%    664
  90%   1067
  95%   3247
  98%   3595
  99%   3846
 100%  10967 (longest request)

Haproxy load balancer + Centmin Mod Nginx web 3

top - 06:51:05 up 33 days, 17:33,  2 users,  load average: 0.26, 0.12, 0.03
Tasks:  27 total,   2 running,  25 sleeping,   0 stopped,   0 zombie
Cpu0  :  8.1%us, 43.9%sy,  0.0%ni, 48.1%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu1  :  0.5%us,  0.8%sy,  0.0%ni, 95.6%id,  3.0%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:   1048576k total,   133192k used,   915384k free,        0k buffers
Swap:        0k total,        0k used,        0k free,        0k cached

Centmin Mod Nginx web 1

top - 06:51:04 up 21 days,  1:52,  1 user,  load average: 0.24, 0.06, 0.02
Tasks:  24 total,   1 running,  23 sleeping,   0 stopped,   0 zombie
Cpu0  :  0.0%us,  0.0%sy,  0.0%ni,100.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu1  :  0.0%us,  0.0%sy,  0.0%ni,100.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:   1048576k total,   126032k used,   922544k free,        0k buffers
Swap:        0k total,        0k used,        0k free,        0k cached

Centmin Mod Nginx web 2.

top - 06:51:05 up 9 days, 10:04,  1 user,  load average: 0.15, 0.04, 0.01
Tasks:  28 total,   1 running,  27 sleeping,   0 stopped,   0 zombie
Cpu0  :  0.0%us,  0.0%sy,  0.0%ni,100.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu1  :  0.0%us,  0.0%sy,  0.0%ni,100.0%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:   1048576k total,   128840k used,   919736k free,        0k buffers
Swap:        0k total,        0k used,        0k free,        0k cached

Nginx worker connections and processes configuration - nginx.conf for all 3x 512MB / 1GB Burst OpenVZ based VPSes (web1-3) 

user              nginx nginx;
worker_processes  1;

worker_rlimit_nofile 51200;

error_log         logs/error.log;

pid               logs/nginx.pid;

events {
    worker_connections  32768;
    use epoll;
}