Load testing with Apache Bench

Overview

We use load testing to check how our application behavior when large number of requests concurrently access the application. This post is about how to do a simple load test with Apache Bench.

Install Apache Bench

Apache Bench(AB) is simple command line load testing tool for web servers. First install Apache bench with Apache utils.
sudo apt-get install apache2-utils

For windows you can download XAMPP or WAMP and since Apache bench is independent file it will be in bin file as ab.exe.
in xampp,
.\xampp\apache\bin\ab.exe
by running ab.exe you can start Apache bench.

How to perform simple load test 

You can do simple load test with your web server url .

ab -n 10 -c 10 http://waruapz.blogspot.com

Here I have just enter my blog url. Change it with your application url.

Here ,

n = requests     Number of requests to perform

c = concurrency  Number of multiple requests to make

You can the output as follows.

Benchmarking waruapz.blogspot.com (be patient).....done

Server Software:        GSE

Server Hostname:        waruapz.blogspot.com

Server Port:            80

Document Path:          /

Document Length:        87007 bytes

Concurrency Level:      10

Time taken for tests:   18.041 seconds

Complete requests:      10

Failed requests:        0

Write errors:           0

Total transferred:      874030 bytes

HTML transferred:       870070 bytes

Requests per second:    0.55 [#/sec] (mean)

Time per request:       18041.184 [ms] (mean)

Time per request:       1804.118 [ms] (mean, across all concurrent requests)

Transfer rate:          47.31 [Kbytes/sec] received

Connection Times (ms)

              min  mean[+/-sd] median   max

Connect:       51   76  18.5     79     105

Processing:  8412 13681 3090.4  14737   17990

Waiting:      459 1580 807.1   1566    2655

Total:       8491 13757 3096.1  14834   18041

Percentage of the requests served within a certain time (ms)

  50%  14834

  66%  15042

  75%  16572

  80%  16710

  90%  18041

  95%  18041

  98%  18041

  99%  18041

 100%  18041 (longest request)

Here you can see some stats about testing like number of requests per secong ,maximum and minimum processing time etc.

Other Apache Bench parameters  can be listed with ab command as below.

ab

ab: wrong number of arguments

Usage: ab [options] [http[s]://]hostname[:port]/path

Options are:

    -n requests     Number of requests to perform

    -c concurrency  Number of multiple requests to make

    -t timelimit    Seconds to max. wait for responses

    -b windowsize   Size of TCP send/receive buffer, in bytes

    -p postfile     File containing data to POST. Remember also to set -T

    -u putfile      File containing data to PUT. Remember also to set -T

    -T content-type Content-type header for POSTing, eg.

                    'application/x-www-form-urlencoded'

                    Default is 'text/plain'

    -v verbosity    How much troubleshooting info to print

    -w              Print out results in HTML tables

    -i              Use HEAD instead of GET

    -x attributes   String to insert as table attributes

    -y attributes   String to insert as tr attributes

    -z attributes   String to insert as td or th attributes

    -C attribute    Add cookie, eg. 'Apache=1234. (repeatable)

    -H attribute    Add Arbitrary header line, eg. 'Accept-Encoding: gzip'

                    Inserted after all normal header lines. (repeatable)

    -A attribute    Add Basic WWW Authentication, the attributes

                    are a colon separated username and password.

    -P attribute    Add Basic Proxy Authentication, the attributes

                    are a colon separated username and password.

    -X proxy:port   Proxyserver and port number to use

    -V              Print version number and exit

    -k              Use HTTP KeepAlive feature

    -d              Do not show percentiles served table.

    -S              Do not show confidence estimators and warnings.

    -g filename     Output collected data to gnuplot format file.

    -e filename     Output CSV file with percentages served

    -r              Don't exit on socket receive errors.

    -h              Display usage information (this message)

    -Z ciphersuite  Specify SSL/TLS cipher suite (See openssl ciphers)

    -f protocol     Specify SSL/TLS protocol (SSL3, TLS1, or ALL)

Apache bench mark mainly use for simple projects. There are other tools like Jmeter, Soap-ui use vastly in industry.