Performance... no more than 150 leases per second?

[Christian Hammers]

Hello

I'm playing around with ISC dhcpd to get enough performance for a really big
network with 60000 clients that have a very short lease time of only half an
hour which calculates to about 33 leases per second.

After starting dhcpd on a pretty decent server with lots of RAM and some
3GHz cores I ended up with about 100-150 leases per second.

While this was more than I need I still wonder what exactly limits the
server. dhcpd was running with 99% CPU and almost no I/O as I put the
leases directory on /dev/shm/ (just for testing!).

That server can handle 1000 MySQL queries per second and not more than
150 dhcpd leases (at 99% CPU!) which should be a lot easy to calculate?

bye,

-christian-



client:/usr/local/nom/bin/dhcperf --retain-leases  --server x.x.x.x 
  --test-duration 600 --test-load 300 --clients 100000 
  --progress --discover     


server:/usr/local/src/dhcp-4.1.1# server/dhcpd -V
Internet Systems Consortium DHCP Server 4.1.1

server:/usr/local/src/dhcp-4.1.1# grep -v ^# /etc/dhcpd.conf
default-lease-time 3600;
max-lease-time 3600;
ddns-update-style none;

deny duplicates;
authoritative;
one-lease-per-client true;

log-facility local6;

ping-check false;

key defomapi {
   algorithm hmac-md5;
   secret se32and6tK6xxxxxxxxx;
};

option domain-name-servers 81.173.197.16;

omapi-key defomapi;
omapi-port 7911;


shared-network test {
subnet 10.10.0.0 netmask 255.254.0.0 {
   pool {
      deny dynamic bootp clients;
      range 10.10.0.2 10.11.255.254;
   }
   option bootfile-name "1.2.3.10";
   option routers 10.10.0.1;
}

subnet 1.2.3.42 netmask 255.255.255.255 {
}

subnet 1.2.3.51 netmask 255.255.255.255 {
}

subnet 1.2.3.39 netmask 255.255.255.255 {
}
}

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