Web Server Benchmarking

1.Web site load analysis
2.performance tests

Web server benchmarking is useful in testing your infrastructure to see if it can with stand expected visitor growth and maintain a reasonable response under load
(i.e. requests per sec, latency, bandwidth).

>>Apache Benchmark Tool: ab
>>Benchmarking Tool: httperf

Apache Benchmark Tool: ab

The Apache httpd web server comes with a benchmarking tool to simulate a high load and to gather data for analysis.

>ab -n 1000 -c 10 -g test_data.txt http://www.karthik.com/index.html

Option Description
-n number of requests. Default is 1 which is useless.
-c concurrent requests. Default 1
-g GNU plot output. Labels are on first line of output.
-q Suppress progress stattus output to stderr.
-t Time limit. Maximum number of seconds.
-A username:password Specify authentication credentials.
-X proxy[:port] Specify a proxy server.

Console output:
Finished 1000 requests


Server Software: Apache/2.2.3
Server Hostname: www.karthik.com
Server Port: 80

Document Path: /index.html
Document Length: 83241 bytes

Concurrency Level: 10
Time taken for tests: 14.793312 seconds
Complete requests: 1000
Failed requests: 0
Write errors: 0
Total transferred: 83608000 bytes
HTML transferred: 83241000 bytes
Requests per second: 67.60 [#/sec] (mean)
Time per request: 147.933 [ms] (mean)
Time per request: 14.793 [ms] (mean, across all concurrent requests)
Transfer rate: 5519.25 [Kbytes/sec] received

Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 20 250.2 0 3000
Processing: 53 126 52.7 120 317
Waiting: 19 51 29.5 46 246
Total: 53 147 260.2 120 3305

Percentage of the requests served within a certain time (ms)
50% 120
66% 142
75% 159
80% 172
90% 198
95% 227
98% 282
99% 314
100% 3305 (longest request)

This shows the load limit of the server.
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Benchmarking Tool: httperf

Web performance benchmarking tool httperf. Httperf sends requests to the web server at a specified rate and gathers stats. Increase till one finds the saturation point.
Installation:

* apt-get install httperf

Example usage:

* Print performance stats for home page of your-domain.com: httperf --hog --server www.your-domain.com
* Create 100 connections at a rate of 10/sec: httperf --hog --server http://www.your-domain.com/ --num-conn 100 --rate 10 --timeout 5
* Generate 10 sessions at a rate of one session/sec every 2 seconds: httperf --hog --ser=www --wsess=10,5,2 --rate 1 --timeout 5

httperf command line options:

Command Command Description
--hog Use as many TCP ports as necessary to generate stats (else limited to port 1024-5000)
--num-calls Session oriented workloads.
--max-connections=# Limit the number of connections to that specified.
--num-calls=# Specify the number of calls to issue on each connection before closing it.
--server host-name Default localhost. Specify IP address of host name.
--wsess=N1,N2,X Specify session where
N1: number of sessions
N2: number of calls per session
X: delay between calls (sec)
--timeout Stop if there is no response within timeout period.