Load Testing Web Servers with apache benchmark tool

Command to run the Apache benchmark tool (ab) with 200 simultaneous requests until 2000 requests are completed:

# ab -k -c 100 -n 2000 localhost/checkiffileexists.php

Let’s run the test and compare the results. Pay attention to the performance statistics:

Apache Performance Load Testing
Apache Performance Load Testing

As you can see, the performance of the server with the event is highly superior to its prefork counterpart in every aspect of this test.

This is the php code that I’ve saved into a file named checkiffileexists.php:

<?php
$filename = 'test.php';

if (file_exists($filename)) {
    echo "The file $filename exists";
} else {
    echo "The file $filename does not exist";
}
?>

Suppose you wanted to test multiple URL’s concurrently as well? You can do this by creating a shell script, with multiple ab calls. At the end of each line place, this makes the command run in the background and lets the next command start execution. You will also want to redirect the output to a file for each URL using > filename For example:

#!/bin/sh

ab -n 100 -c 10 http://127.0.0.1:8300/test.cfm > test1.txt &
ab -n 100 -c 10 http://127.0.0.1:8300/scribble.cfm > test2.txt &

The usage info from the ab version installed on my Mac (v2.3) is listed below. As you can see there are many useful options for outputting results, and sending additional data in the request.

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
    -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 (SSL2, SSL3, TLS1, or ALL)

By anup

Leave a Reply

Your email address will not be published. Required fields are marked *