[c-nsp] high performance open source DHCP solution?

[Lincoln Dale]

On 20/07/2011, at 12:24 PM, Rogelio wrote:

> The free DHCP solution, ISC, seems to be having scaling issues (i.e.
> handling only about 200 DHCPDISCOVER and 20 DHCPRENEW requests), and I
> was wondering if anyone had any open source suggestions of solutions
> that could scale much better?
> 
> (Ideally, I could find a free version of a solution like Nominum, but
> I know that's asking for much.)
> 
> Anyone have any suggestions?

one suggestion i have is that i'd be surprised if the ISC DHCP server is somehow limited to the 200 / 20 numbers you state.
the order of "200 requests/sec" is a round number that is awfully close to the IOPS of a modern 7200rpm drive.

which makes me think that the ISC code is likely doing a fsync() and thats why you're seeing this magic 200 number.

a simple way to make it go faster would be to try it out on a SSD.
but likely there are options for tuning said dhcp server code such that it delays or batches fsync, or can operate with an in-memory index instead.

all of the above is pure speculation.  i neither run a DHCP server or infrastrcture, but i have had experience in tuning systems that require consistently stored persistent data.


cheers,

lincoln.