Chandy and Lamport's Global Snapshot Algorithm

It is the implementation of Chandy and Lamport's snapshot algorithm with distributed banking as an example.
In this project, we instantiate three bank branches before the inspector records the global state, by default.
We can change it by adding new branch information in the config.yml file under the section branches.
By default, transactions are performed every 0.5 seconds. We can change it too by modifying the time_step variable in config.yml under the section bank.
A few other options are also available in the same config_file.

Note: A branch can initiate a snapshot at any time by pressing s in its terminal.

Platform

Although thorough testing of the project was done on Ubuntu and Arch Linux, it should run fine on other operating systems as well.

Dependencies

The project uses the libraries provided on the default installation of Python. The only dependency is pyyaml which is required for reading configuration file.
You can install it by running the following command:

# if Python Version 2 and 3 are both installed on your system,
# you might need to use `pip3` instead of pip.
pip install -r requirements.txt

Feel free to change the code to make it run on your version of Python in your machine

Instructions to Run the Code

0. Clone this repository and change your current working directory.

git clone https://github.com/nrasadi/global-state-snapshot.git
cd global-state-snapshot

1. Instantiate at least the minimum number of branches of the bank. Type the command below in different terminals.

python main.py -b

2. Instantiate inspector of the bank.

python main.py -i

Now, the code will run as a simulation.
Type s in respective branches for snapshot.

Logs

All transfer messages get logged into logs/ directory.
Each branch has its own log file. Same is true for the inspector.

Next Runs

When you open enough terminals and run the program, it creates two directories:

• logs/ (as mentioned above)
• bank/: public information of each branch, e.g., its id and ip address is kept here.

Note: When you want to run the program again, you need to remove these two directories. It can be done using the following command:

python main.py -c