Static Web Content test

A simple scalability test of an Apache Web server, serving static files.

The aim was to establish the behaviour of a simple Web server (like the one used by the gldiein factory) under heavy stress.

Test setup

Server:

• 2 x Dual Core AMD Opteron(tm) Processor 275
• 8GB RAM
• Gigabit Etherent LAN
• Using Apache 2.2.3 on CentOS? 5.5

Clients:

• CMS T2 worker nodes @UCSD
• Accessed via the Grid using the glideTester
• Using wget for download

Transferring a small file

For this test, a small file of about 1k was being accessed by the clients.

The Web server held very well with about 400Hz to about 1k concurrent clients.After that clients startto see problems.

The load on the server is minimal, and the network is underutilized at about 6Mbits/s.

Transferring a larger file

For this test, a larger file, of about 10M was being accessed by the clients.

The Web server held very well with about 10Hz to all the way to the max 1k concurrent clients tested.

Concurrency	Success	Failure	Stuck clients
10	25k (10Hz)	0	0
50	25k (11Hz)	0	0
100	25k (11Hz)	0	0
150	25k (11Hz)	0	0
300	25k (11Hz)	0	0
200	26k (11Hz)	0	0
400	26k (11Hz)	0	0
600	26k (11Hz)	0	0
800	26k (11Hz)	1 (0Hz)	0
1000	27k (11Hz)	0	0

This time, the load on the server was higher, but still only using about half of one core. The network was also much more used, but still underutilized at about 70Mbits/s.

-- IgorSfiligoi - 2011/04/05