Investigating the Impacts of Web Servers on Web Application Energy

Usage

Computer and Information Sciences University of Delaware

Irene L. Manotas G.Cagri Sahin

James ClauseLori Pollock

Kristina Winbladh

Which Web Server Should I Use?

Empirically Investigate

• RQ1—Feasibility: Does the choice of web server impact the energy consumption of a web application?

• RQ2—Consistency: Are the web servers

consistent in their impact?

2

Experimental Setup

web browser

3

workloads

web serverweb application

LEAP energy monitor

Integration Tests

Automatic Testing

user inputs

3

WEBRick

4

% Difference in energy consumption from the mean

Web Servers

Feature Mongrel Puma Thin WEBrickCalendar 10.10 -6.10 -8.50 2.30Context Edit -1.40 -2.10 -0.10 3.40Preferences -4.00 8.70 -4.00 -1.80Review -1.10 -6.30 -1.30 7.70Search 1.80 4.10 5.90 -0.60Show Statistics 2.70 6.10 -13.90 2.90Toggle Context -3.00 4.70 7.20 -10.70

Total 1.70 0.10 -3.60 1.70 A given web server is not always the best under all features.

The web server does make a difference Energy consumption variability differs across

features.

4 4This work is supported in part by National Science Foundation Grant No. 1216488 and an award from the University of Delaware Research Foundation

Results: Feasibility and Consistency

• Correlating energy measurements with design decisions/implementations in a non-tedious manner

5

Issues We Face

Questions for Discussion• How are others monitoring and mapping energy

usage to program units?• How many repeated runs do others perform to

take measurements to account for variations?