Apache Bench for load testing and performance benchmark

Apache Bench for Load Testing

AB( Apache Bench) is a command line utility to measure performance of any web server. It’s originally designed to test the Apache HTTP server. AB is free open source software and distributed under the terms of the Apache License.

It’s good practice to Benchmark performance of the any server before deployment. AB tool will shows you how many request per second your webserver can handle.

To measure performance of web server pass a certain number of concurrent request and some number of repetition and check AB result. I would recommend you start from small concurrent and repetition. Increase the number of concurrent request and repetition untill your result not fail or your webserver load reaches your defined limit.

Installation:

In Ubuntu: 

Refresh the package database.

$ apt-get update

Install the apache2-utils package to get access to ApacheBench.

$ apt-get install apache2-utils

In Redhat or Centos:

Install httpd-tools to get AB tool.

$ yum install httpd-tools

Usages:

$ ab -n 10 -c 10 http://localhost/index.php

Parameter Description:

• -n 10: ab will send 10 number of requests to server localhost.
• -c 10 : 10 multiple requests to perform at a time. Default is one request at a time.

Output:

ab -n 10 -c 10 http://localhost/index.php
This is ApacheBench, Version 2.3 <$Revision: 655654 
gt;

Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/

Licensed to The Apache Software Foundation, http://www.apache.org/
Benchmarking localhost (be patient).....done
Server Software:        Apache

Server Hostname:        localhost

Server Port:            80

Document Path:          /

Document Length:        38879 bytes

Concurrency Level:      10

Time taken for tests:   6.401 seconds

Complete requests:      10

Failed requests:        0

Write errors:           0

Total transferred:      392381 bytes

HTML transferred:       388790 bytes

Requests per second:    1.56 [#/sec] (mean)

Time per request:       6400.818 [ms] (mean)

Time per request:       640.082 [ms] (mean, across all concurrent requests)

Transfer rate:          59.86 [Kbytes/sec] received
Connection Times (ms)

min  mean[+/-sd] median   max

Connect:      365  366   0.7    366     367

Processing:  2214 3170 1171.5   3006    6020

Waiting:     1634 2424 775.4   2430    3924

Total:       2580 3537 1171.6   3371    6387
Percentage of the requests served within a certain time (ms)

50%   3371

66%   3580

75%   3603

80%   4516

90%   6387

95%   6387

98%   6387

99%   6387

100%   6387 (longest request)