[NOT UPDATED]

Introduction

RaftP4 is a dataplane-layer implementation of Raft's Consensus algorithm that uses UDP segments, crafted using Scapy 2.4.2 (see references). This implementation provides the following features:

• leader election
• log replication
• node recovery (under some specific circumstances)

Getting started

download and run the VM of P4lang (it's the fastest way to get a working environment).

This project relies on Mininet, using P4's BMV2 switches. The topology is described in topology.png

When ready, navigate to the cloned/downloaded folder of this project, open a shell and run:

make run

at this point, you should see the Mininet shell.

Running the application

open another terminal and type:

python Switch_Register_Manager.py -a

This will set the correct parameters to run Raft inside P4 devices.

inside mininet prompt, run

xterm h1 h2 h3

to open the emulated hosts' terminal. H1 will be the controller.

on h1 terminal type

python packet_sender.py --command 0xA --term 0 --destination 10.0.1.254

parameters:

• --command (-c) : is the messageType that will be sent to the device specified (full list of message types is inside the packet_sender.py script).
• -- term (-t) : is the Raft term (Be careful, in the actual status, if the term is less than the term inside the devices, the packet will be dropped).
• --destination (-d) : IP destination on whom to send the packet.

Value Consensus

Send a timeout packet to one of the devices (--command 0xA or in Int format --command 10)

e.g.: in another terminal:

python packet_sender --command 0xA -d 10.0.1.254 -t 0

Use now the Switch_Register_Manager.py tool to verify that the node who performed the timeout is the actual leader:

python Switch_Register_Manager.py -ra --port 9090

Useful mininet commands

example to bring down a link, type inside the mininet shell

sh ifconfig s1-eth1 down

Improvements

Troubleshooting

• if you have errors by running the application, most probably you have to check inside the makefile and fix the path of BMV2 and P4C
• If mininet shows an error like Error creating interface pair: RTNETLINK answers: File exists on start, try 'make stop' and then again 'make run'

Known Issues

References

Raft
Scapy
P4