[squid-users] Re: Delay Pools question

> ... what the number after the slash in delay_parameters represents. [?]
> [for example what means:] delay_parameters 2 64000/64000 10000/10000000

You can think of the two numbers separated by a slash as the "average rate" and the "peak burst size". In other words the first number is "how much bandwidth on average" and the second number is "the largest file that can sometimes be transferred faster than the the average rate".

So in the example the burst size of 64000 not being different from the average rate of 64000 pretty much eliminates bursting at that level. The burst size of 10000000 allows larger files to transfer quickly (of course subject to higher levels) if nothing else is going on, even though the average rate is the much lower 10000.

The numbers are really the two parameters of the 'leaky bucket' algorithm: the replenishment rate and the bucket volume (numbers that exceed the bucket volume "spill over" the top of the 'leaky bucket' and are lost). But this real meaning tends to not be all that helpful in choosing your configuration values.

So use the ideas "average rate" and "peak burst size" to choose your initial configuration values. Then be prepared to 'adjust' them up or down quite a bit -typically by a factor of two or even more- based on your actual experience.

thanks! -Chuck Kollars

      
Received on Fri Aug 15 2008 - 17:38:08 MDT