You can do this in several ways. Apache has some support for this with a module, but we'll show how Linux can do this for you, and do so for other services as well. These commands are stolen from a presentation by Jamal Hadi that's referenced below.
Let's say we have two customers, with http, ftp and streaming audio, and we want to sell them a limited amount of bandwidth. We do so on the server itself.
Customer A should have at most 2 megabits, customer B has paid for 5 megabits. We separate our customers by creating virtual IP addresses on our server.
# ip address add 126.96.36.199 dev eth0 # ip address add 188.8.131.52 dev eth0
It is up to you to attach the different servers to the right IP address. All popular daemons have support for this.
We first attach a CBQ qdisc to eth0:
# tc qdisc add dev eth0 root handle 1: cbq bandwidth 10Mbit cell 8 avpkt 1000 \ mpu 64
We then create classes for our customers:
# tc class add dev eth0 parent 1:0 classid 1:1 cbq bandwidth 10Mbit rate \ 2MBit avpkt 1000 prio 5 bounded isolated allot 1514 weight 1 maxburst 21 # tc class add dev eth0 parent 1:0 classid 1:2 cbq bandwidth 10Mbit rate \ 5Mbit avpkt 1000 prio 5 bounded isolated allot 1514 weight 1 maxburst 21
Then we add filters for our two classes:
##FIXME: Why this line, what does it do?, what is a divisor?: ##FIXME: A divisor has something to do with a hash table, and the number of ## buckets - ahu # tc filter add dev eth0 parent 1:0 protocol ip prio 5 handle 1: u32 divisor 1 # tc filter add dev eth0 parent 1:0 prio 5 u32 match ip src 184.108.40.206 flowid 1:1 # tc filter add dev eth0 parent 1:0 prio 5 u32 match ip src 220.127.116.11 flowid 1:2
And we're done.
FIXME: why no token bucket filter? is there a default pfifo_fast fallback somewhere?