rafathasan/raspi-mpi-cluster

MPI is a standardized and portable message-passing standard designed to function on parallel computing architectures on Raspberry Pi. The MPI standard defines the syntax and semantics of library routines that are useful to a wide range of users writing portable message-passing programs in C++.

Pre-requisite

• Get yourself a Linux OS. Ubuntu Prefered
• Download the Pre-build Raspbian, Link

Things are done in pre-build raspbian (no need to run if you download the pre-build raspbian)

MPICH installed.

$ sudo apt-get update && sudo apt-get install mpich

Change Keyboard layout

keyboard layout /etc/default/keyboard -> XKBLAYOUT="us"

Disable onboard WiFi

$ echo "dtoverlay=pi3-disable-wifi" | sudo tee -a /boot/config.txt

Disable Bluetooth

$ echo "dtoverlay=pi3-disable-bt" | sudo tee -a /boot/config.txt

Disable systemd service UART

$ sudo systemctl disable hciuart

Set Autologin CLI

$ sudo raspi-config nonint do_boot_behaviour B2

Set LAN wait on Boot

$ sudo raspi-config nonint do_boot_wait 1

Start SSH on boot

$ sudo raspi-config nonint do_ssh 1

Image Installation after Downloading the pre-build raspbian

$ gzip -d mpi_raspbian_lite.img.gz

$ dd if=clone.img of=/dev/sdX

---

Setting Up Cluster

Terminology

• Each Node need to be connected to master Node in order to run the execution command from the master. This will be done via SSH. We are going to override SSH authorization to get rid of human-interaction and make it automate to commnucate seamlessly node to node.
• In order to run the execution command, the source file must exsist on each nodes. Here comes the shared data, we can use NFS Server which stands for network file system. we need to modifiy some of its configuration to allow outbound connection and auto mount the file system in the slave nodes.

Setting up Master Node

Install NFS Server on Master

$ sudo apt-get install nfs-server

Make shared Folder in Home Directory

$ mkdir shared

Change Directory Permission

$ sudo chmod -R 777 shared

Set shared folder on NFS Server

$ echo "/home/pi/shared nfs 192.168.0.100(rw, sync, no_root_squash,no_subtree_check)" >> /etc/exports

Create a List of IPs of Nodes -> ~/nodes.txt

192.168.0.100
192.168.0.101
192.168.0.102
192.168.0.103
192.168.0.104
192.168.0.105

Set Node Hostname

$ nano /etc/hosts

192.168.0.100 master
192.168.0.101 node1
192.168.0.102 node2
192.168.0.103 node3
192.168.0.104 node4
192.168.0.105 node5

Create SSH Master key
Hit Enter Do not Enter Passphase

$ ssh-keygen

Login through SSH to Slave Nodes and create SSH key
Hit Enter Do not Enter Passphase

$ ssh [email protected]

nodeX$ ssh-keygen

nodeX$ scp master:/home/pi/.ssh/id_rsa.pub /home/pi/.ssh/authorized_keys

nodeX$ exit

Get Slave SSH key via SCP

$ scp nodeX:/home/pi/.ssh/id_rsa.pub /dev/stdout && cat /dev/stdout >> /home/pi/.ssh/authorized_keys

Setting up Slave Node (Do this on Each Slave Node)

Set Master Node Hostname

$ echo"192.168.0.100 master" >> /etc/hosts

Create shared directory

$ mkdir shared

Setting Up Auto Mount on Boot

$ echo "master:/home/pi/shared /home/pi/shared nfs rwx 0 0"

Reboot Slave Node

$ sudo reboot

Check if the NFS Diretory Mounted
check for 'master' hostname

$ df -h

Testing MPI Cluster on Master

Create machinefile

nano machinefile

master
node1
node2
node3
node4
node5

Check if All node respond

$ mpiexec -f machinefile -n 6 hostname

you will see the output look like this

master
node1
node2
node3
node4
node5