Switcharoo Experiments

This repository contains the evaluation scripts used to measure Switcharoo performance.

Repository Organization

This repository contains:

• generator: FastClick elements and scripts used to generate traffic towards a Tofino switch;
• switcharoo_mcast: P4 program that takes incoming packets, manipulates their flow tuple to generate synthetic flows using some configuration parameters and multicasts them towards Switcharoo;
• tests: evaluation scripts and results plotter.

The experiments require two Tofino switches and an external server that acts as a traffic generator and measurements gatherer.

Traffic Generator

The traffic generator uses FastClick, in particular, it needs some additional elements to be compiled inside the vanilla version.

We used Ubuntu 20.04.4 LTS as the Operating System on the server.

First compile and install DPDK, following this tutorial. We used DPDK 21.08.0, and it is the only tested version.

After installing DPDK, pull both this repository and FastClick:

$ git clone https://github.com/Switcharoo-P4/Switcharoo-Experiments.git
$ git clone https://github.com/tbarbette/fastclick.git

Checkout to the specific FastClick commit (cf0f2b507c):

cd fastclick
git checkout cf0f2b507c6fcb1e4f99a834912f62a262fb8e9c

Enter the Switcharoo-Experiments folder and copy the generator/fastclick/elements folder inside the root folder of FastClick, where there is already an elements folder. Confirm to merge the two.

Install FastClick's dependencies by running the deps.sh script.

In our testbed, FastClick has been configured with the following command:

$ cd fastclick
$ PKG_CONFIG_PATH=/path/to/dpdk/install/lib/x86_64-linux-gnu/pkgconfig ./configure --enable-dpdk --enable-intel-cpu --verbose --enable-select=poll "CFLAGS=-O3" "CXXFLAGS=-std=c++17 -O3" --disable-dynamic-linking --enable-poll --enable-bound-port-transfer --enable-local --enable-flow --disable-task-stats --enable-cpu-load --enable-dpdk-packet --disable-clone --disable-dpdk-softqueue --enable-research --disable-sloppy --enable-user-timestamp

Replace the PKG_CONFIG_PATH with the path of your DPDK installation.

Build the project:

$ make

NOTE: In order to run the CAIDA experiment, you need a CAIDA trace locally stored on the server. Providing such trace is out of the scope of this repository. However, if you have the trace, you need the change the trace path in the generator/gen-trace.click file (from line 17 to line 24).

Multicast P4 Program

You need a Tofino to build and run the switcharoo_mcast program. This Tofino switch should be connected with some ports to the Switcharoo Tofino. The default configuration uses four ports.

To build the code, use the following command:

./p4_build.sh /path/to/switcharoo_mcast.p4

switcharoo_mcast.p4 has been tested on SDE 9.7.0.

Tests

In this folder, you will find both the bash scripts to run the paper experiments and a plot.py to plot all the figures of the paper.

The plot.py requires matplotlib:

python3 -m pip install matplotlib

Configuration

Change the FastClick configuration

You need to specify the FastClick installation directory in the gen-rated-mt-lat.sh and gen-trace.sh files. Also, you need to specify the interface PCI address of the NIC port to use to send traffic.

Open the gen-*.sh files with an editor and change the /path/to/fastclick with the root folder of the compiled FastClick. To change the port, replace -a 3b:00.1 with the interface PCI address of your NIC port.

FastClick is started using 16 threads, but the generator scripts only require 4 threads. You can change the number of threads in the gen-*.sh files by changing the -l 0-15 parameter to a different range.

Change Ports in switcharoo_mcast

The figure above depicts the Switcharoo's testbed with the associated port names. For more information about the Switcharoo Tofino ports, please refer to the dedicated repository.

To change the ports in the switcharoo_mcast program, you need to:

• Change the switcharoo_mcast.p4 defines:

#define PKTGEN_PORT 36
#define PKTGEN_IP 0x0a1b3cd6

#define OUTPUT_PORT_1 48
#define OUTPUT_PORT_2 52
#define OUTPUT_PORT_3 44
#define OUTPUT_PORT_4 40

• Change the setup*.py files:

MCAST_PORTS = [48, 52, 44, 40]

• Change the run_pd_rpc/setup.py file:

PKTGEN_PORT = 36
MCAST_PORTS = [48, 52, 44, 40]

You then need to recompile the P4 program.

Changing Traffic Patterns in switcharoo_mcast

switcharoo_mcast has three different traffic patterns (which are the ones described in the paper).

You can define a new traffic pattern by changing the following registers:

bfrt.switcharoo_mcast.pipe.Ingress.base_flow_ip.mod(f1=0x01000001, REGISTER_INDEX=0)
bfrt.switcharoo_mcast.pipe.Ingress.number_of_ip.mod(f1=65535, REGISTER_INDEX=0)
bfrt.switcharoo_mcast.pipe.Ingress.n_packets_per_flow.mod(f1=2, REGISTER_INDEX=0)
bfrt.switcharoo_mcast.pipe.Ingress.max_port.mod(f1=65535, REGISTER_INDEX=0)
bfrt.switcharoo_mcast.pipe.Ingress.consecutive_flows_number.mod(f1=125, REGISTER_INDEX=0)
bfrt.switcharoo_mcast.pipe.Ingress.flows_repetition.mod(f1=4, REGISTER_INDEX=0)

• base_flow_ip: base flow IP to start the generation;
• number_of_ip: number of IPs to generate;
• n_packets_per_flow: number of packets per each flow;
• max_port: maximum L4 port value;
• consecutive_flows_number: number of consecutive flows before changing values;
• flows_repetition: number of repetitions for each consecutive flow.

Configure Test Scripts

You need to define some variables in the bash scripts to run the tests. In each run_experiment_*.sh file, you will find the following variables:

SERVER_USERNAME="user"
SERVER_USER_PASS="pass"
TOFINO_USERNAME="tofino"
TOFINO_USER_PASS="tofino"
SWITCHAROO_TOFINO_NAME="tofino32p"
MCAST_TOFINO_NAME="tofino64p"
GENERATOR_SERVER_NAME="nslrack25"

SWITCHAROO_PATH="/absolute/path/to/switcharoo"
MULTICAST_PATH="/absolute/path/to/switcharoo_mcast"
GENERATOR_PATH="/absolute/path/to/generator"

MULTICAST_TOFINO_SDE="/home/tofino/bf-sde-9.7.0"
SWITCHAROO_TOFINO_SDE="/home/tofino/bf-sde-9.8.0"

• SERVER_USERNAME: the Linux user on the server used as a generator;
• SERVER_USER_PASS: the user password on the server used as a generator;
• TOFINO_USERNAME: the Linux user on both Tofinos;
• TOFINO_USER_PASS: the user password on both Tofinos;
• SWITCHAROO_TOFINO_NAME: the name/IP of the Tofino where Switcharoo is installed;
• MCAST_TOFINO_NAME: the name/IP of the Tofino where switcharoo_mcast is installed;
• GENERATOR_SERVER_NAME: the name/IP of the server used as a generator;
• SWITCHAROO_PATH: path in the Tofino to the Switcharoo code and setup.py file;
• MULTICAST_PATH: path in the Tofino to the switcharoo_mcast code and setup*.py files;
• GENERATOR_PATH: path in the server where the FastClick scripts contained in the generator folder are located;
• MULTICAST_TOFINO_SDE: SDE path in the Tofino where switcharoo_mcast is installed;
• SWITCHAROO_TOFINO_SDE: SDE path in the Tofino where Switcharoo is installed.

Run The Experiments

After configuring the project, you can run all the experiments by typing the following command:

sh run_all_experiments.sh

You can also run a single experiment by running the specific run_experiment_*.sh file.

Check the content of the file for the specific parameters to pass.

Plotting the results

After you gathered all the results, you can plot them by running the following command:

python3 plot.py <table_size_results> <table_size_no_ordering_results> <bloom_size_results> <throughput_results> <figures_path>

NOTE: For Figure 7 (<table_size_no_ordering_results>), you need to recompile Switcharoo by replacing the bloom_pipe/bloom.p4 with the bloom_pipe/bloom_no_ordering.p4 and recompile the program.