Distributed Computing



Distributed computing technology breaks a problem into parallel tasks running on two or more computers. With the convergence of low-cost processors and high speed networks, computer clusters have emerged as an affordable solution to do-it-yourself distributed computing and high-availability. Multiple miniature computers are connected to perform distributed computing.



Raspberry Pi Organization (raspberrypi.org) offers a pocket-sized single-board computer for approximately $35 USD. Several versions of the free Linux operating system are available for the Raspberry Pi.



For each computer, static IP addresses are assigned.

cat /etc/network/interfaces
iface eth0 inet dhcp
sudo ifconfig

Make note of the inet addr, bcast, and mask.
192.168.1.???, 192.168.1.255, 255.255.255.0
sudo route -nee

Make note of the gateway address.

Interfaces file can be updated to set static information with nano.

sudo nano /etc/network/interfaces

Delete ""iface eth0 inet dhcp" and add the following:

iface eth0 inet static
address 192.168.1.???
netmask 255.255.255.0
network 192.168.1.0
broadcast 192.168.1.255
gateway 192.168.1.1

*??? placeholder for number you select

Ctrl+X, then Y to save.

Example of IP addresses for 4 computers:
192.168.1.50
192.168.1.51
192.168.1.52
192.168.1.53

With static IP addresses configured, the University of Cambridge hosts a tutorial on computation between 2 computers. Python source code included: Distributed Computing Demo (Cambridge)

Each computer requires MergeSort.py and Merge1.py. The host machine will have MergeServer.py and the client machine will have MergeClient.py. When tested, the following results were returned: 10 seconds vs. 7.87 seconds.







Raspberry Pi computer communicating through FM radio

1. Configure Raspberry Pi computer.



2. Download and install the computer talker program "festival" with command:
sudo apt-get install festival

3. Once downloaded and installed, plug in a speaker to your Raspberry Pi computer and enter the command to hear your computer talk:
echo "computer is talking." | festival --tts

4. Save the message as a WAV file with the command:
echo talk | text2wave >op.wav

5. Install FFMPEG with the command
sudo apt-get install ffmpeg

6. Convert the op.wav file to 22050kHz with the command:
ffmpeg -i "op.wav" -y -ar 22050 "op.wav"

7. Install PiFM to get your computer to send messages over the radio with the following commands:
wget http://omattos.com/pifm.tar.gz

Once downloaded, extract with this command:
tar -xvzf pifm.tar.gz

8. Tune a radio to 88.1 FM and execute the following command:
sudo ./pifm op.wav 88.1



Results are transmitted to your FM radio to frequency 88.1.



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