bandwidth and traffic simulator for web apps?

Question

Can you suggest how to create a test environment to simulate various types of bandwidths and traffic in a web app?

Or maybe an open source program which does this against

Answer 1

Do not forget about Wanulator (http://www.wanulator.de/). The name Wanulator comes from "WAN" and "simulator. This pretty much describes what the software does: It simulates different Internet conditions such as delay or packet loss. Furthermore it simulates user access line speeds e.g. modem, ISDN or ADSL. Wanulator is currently packaged as a Linux boot CD based on SLAX. This will give you a full out of the box experience. You can turn any PC into a test-system within a blink - just by booting the Wanulator CD. The package already includes useful client SW such as web-browser and network sniffer (Wireshark). Nevertheless if the PC has 2 network interfaces the system can run as an intermediate system between your server and your client - as a switch - without any configuration hassles.

Answer 2

If you are running a Linux box as your server, Linux box as your client, or have the capability to put (perhaps a VM) a Linux router between your client and server, you can use NetEm.

NetEm is a Linux TC (Traffic Control) discipline which can delay (i.e. add latency) packets leaving a host. Although it's tricky to set up clever rules (e.g. add latency to some traffic, not to others), it's easy to add a simple "delay everything leaving the interface by 50ms" type rules and some recipes are provided.

By sticking a Linux VM between your client and server, you can simulate as much latency as you like. And you can turn it on and off dynamically. Linux has other TC disciplines which can be combined with NetEm to restrict bandwidth (but the script to set this up can be somewhat complicated). NetEm can also randomly drop packets.

I use it and it works a treat :)

Answer 3

if you're using apache you may want to take a look at apache ab

Answer 4

The closest I can think of is doing something similar with VEDekstop from Shunra..

Simulating High Latency and Low Bandwidth in Testing of Database Applications

Shunra VE Desktop Standard is a Windows-based client software solution that simulates a wide area network link so that you can test applications under a variety of current and potential network conditions – directly from your desktop.

Answer 5

I wrote a php script awhile back which used CURL to run a sequence of page requests against my server which represented a typical use scenario. I had it output the times that it took for the server to respond to each of the requests. I then had another script which spawned a bunch of these test case scripts simultaneously for a sustained period and correlated the results into a file which I could then look at in a spreadsheet to see average times. This way I could simulate the number of users hitting the site that I wanted. The limitations are that you need to run the test script on a different server to the web server and that the client machine can become too loaded to give meaningful results past a certain point. I've since left the job otherwise I would paste the scripts here.

Answer 6

Web Application Stress Tool (WAST) from Microsoft is what you need.

http://www.microsoft.com/downloads/details.aspx?familyid=e2c0585a-062a-439e-a67d-75a89aa36495&displaylang=en