We implemented Stateless Cheetah in P4 on the Tofino to load balancer QUIC connections by storing the Cheetah cookie in the connection ID of the QUIC packet headers.
The code consists of two files:
cheetah_quic_pipeline.p4, which contains the P4 program to handle Cheetah cookies.cheetah_setup.py, which contains the Python commands to populate the P4 switch.comparison_with_simple_hash/, contains the cheetah quic pipeline and a simple hash-based LB for comparing them.
You should have installed our modified version of picoquic (from here) on three machines. One machine is used as a cliente and two machines as the servers.
The VIP of Cheetah is preconfigured to be 192.168.64.1
The DIP of Server-1 is preconfigured to be 192.168.63.16. Server-1 is connected to port 10 (D_P = 52) of the Tofino switch.
The DIP of Server-2 is preconfigured to be 192.168.63.19. Server-2 is connected to port 13 (D_P = 28) of the Tofino switch.
The client is connected to port 9 (D_P = 60) of the tofino switch.
The current P4 program does not handle ARP requests so ARP should be statically set up on the machines and the MAC addresses should be configured in the cheetah_setup.py file.
The LB implementes Weighted Round Robin with 3 buckets. Two first two buckets map to Server-1 and the last bucket to Server-2.
If you plan to change these values, you need to modify them in the cheetah_setup.py file.
Move the files of this repository on a folder
scp cheetah* username@host:$CHEETAH_LAB
where $CHEETAH_LAB is the directory where you plan to store the tofino-related files and host is the IP of the Tofino switch.
$SDE/p4_build.sh $CHEETAH_LAB/cheetah_quic_pipeline.p4
Run the program onto the switch:
$SDE/run_switchd.sh -p cheetah_quic_pipeline
Run in another window the following commands:
$SDE/run_bfshell.sh -b $CHEETAH_LAB/cheetah_setup.py
Ths switch is now running properly.
Prerequisites: generate a file to be fetched by the client and put it into server_files/index.html subdirectory of the picoquic directory where you will run the following commands. Also create a directory client_files where the fetched file will be stored.
Go to Server-1 and run the following command:
./picoquic_sample server 4433 ./certs/ca-cert.pem ./certs/server-key.pem ./server_files 1
Go to Server-2 and run the following command:
./picoquic_sample server 4433 ./certs/ca-cert.pem ./certs/server-key.pem ./server_files 2
Open three tcpdump sessions to spoof traffic at the interfaces of the three machines.
Go to the client and run the following command:
./picoquic_sample client 192.168.64.1 4433 ./client_files index.html
This will generate a request towards the VIP and will be served by Server-1. Check on tcpdump.
Run again the same command at the client. The request will again be served by Server-1. Check on tcpdump
Run again the same command at the client. The request will now be served by Server-2. Check on tcpdump
This cycle repeats for each request sent by a client.