Testing on a LAN
I have the task of testing an 'internal' (LAN based) web based system that will support 500 concurrent users.
The test system I need to performance Test against is a near production scale IBM I-series running webspere/DB2 that sits on the Office LAN.
In the absence of a controlled test LAB, what is the best way to 'load up' this system?
I'm concerned that I may saturate the LAN segments that the load injectors are on (causing bottlenecks) and that other general office traffic will affect the metrics.
I was thinking.
1. Patch may Load Injectors into the same Switch as the I-Series.
2. Testing out of hours (so the network is quiet but will I saturate segments?)
How can i make it a realistic/representative as possible?
Ideally I would patch the i-series and the loadinjectors into a separate dedicated switch but I have been advised that other 'partitions' of the machine are used for other applications. I have been reliably informed that other applications on the other partitions are ring-fenced and will not have any effect on my partition of the system. (As you can probably tell, i have no I-series Experience)
All my previous large scale experience has been on externally facing websites that I drive from it's production DMZ. I have my Load Injectors patched into a production scale switch and then into a production BIG_IP (load balancer).
I've never had to consider other traffic or LAN saturation before from my load injectors before.
Any suggestions/advice would be great.
Re: Testing on a LAN
Sound like you need to test during off-hours.
Also, run a test with a single user and check how many kilo bites per second are being transmitted over the LAN.
Multiply this by number of users you are planning to run, this will give you a good idea about what type of load you are applying to the network. This number could be very insignificant (depending on your application). Ideally, you would be on a different subnet, but since this is not the case try to improvise.