RADIUS Stress Test tool

Michael Lecuyer mjl at theorem.com
Thu Oct 4 17:27:49 CEST 2007

Like most other RADIUS server load testers it merely tests how fast the 
client load test can run and doesn't really test the server load.

The Evolynx tester is especially prone to this problem because you can't 
  set the client time out. And 20 concurrent threads won't result in 
much of a load. And CPU load may not be much of a measure of a server's 

In a number of my own tests I've found that the shorter the time out the 
faster the server appears to run with only slightly more packets being 

What we're seeing is that a long time out can make it appear that all 
packets are being processed but the long time out also slows the client 
load test. If half of those threads are waiting a very short time for 
responses and half are waiting a long time (essentially waiting for the 
short responses to be processed by the server) you're now down to half 
the threads testing the server. As time goes by more and more threads 
are waiting for fewer quick thread responses and the test becomes 

Being able to set the time out to something like one tenth of a second 
can show a significant increase in server packets processed with only a 
slight increase in dropped packets for simple authentication methods. A 
dramatic increase in packet loss usually shows a back end problem. The 
only real way to load test a server is to run many tests from many machines.

For example, I saw the graph of over 100,000 customers using a RADIUS 
accounting server. The dropped packet count was sloping up gradually as 
the morning progressed and more people were using the system. Finally 
the back end server completely bogged down and then the dropped packets 
spiked enormously as customers started re-accounting causing a complete 
failure of the system from which it wouldn't recover until most of the 
customers gave up. That's the test you're looking for and that's the 
load you want :)

Kostas Kalevras wrote:
> O/H tnt at kalik.co.yu έγραψε:
>> You do. ;-)
>> If you have freeradius you have radiusclient.
>> Ivan Kalik
>> Kalik Informatika ISP
>> Dana 4/10/2007, "Amr el-Saeed" <amr.elsaeed at tedata.net> piše:
>>> Dear All,
>>> Does any one have any tool to stress  test the freeRadius ??
> http://www.evolynx.com/radius/dl_loadtest.aspx
>>> regards,
>>> Amr el-Saeed
>>> -
>>> List info/subscribe/unsubscribe? See 
>>> http://www.freeradius.org/list/users.html
>> -
>> List info/subscribe/unsubscribe? See 
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