CountryCrab 🦀

Introduction

CountryCrab is a distributed simulator for physics-inspired optimization solvers. It utilize both multiprocessing and GPU parallelization to maximize the performance (i.e. flips/s). CountryCrab was first used to benchmark Content Addressable Memories approaches to the solution of SAT solvers¹.

Setting up the Jupyter Docker container

The dockerctl script provides options to control building and running the image. Usage is demonstrated below:

cd docker

# this builds an image tagged `camsat`
./dockerctl build camsat

# start Jupyter lab on a port of your choice
./dockerctl run camsat <port>

The terminal output will then instruct you how to connect to the running instance.

After connecting to the Jupyter Lab instance for a better shell UX (full shell prompt and other interactive features) run

exec bash

Installing CountryCrab

After running Docker to install the CountryCrab package run

pip install -e .

Basic usage

An example of basic usage for CountryCrab can be found in tests/basic_usage.ipynb. The first step is to create a configuration and parameters for the experiment. The only necessary field is instance in the configuration file which is the path to the instance to be solved. If not other parameters are specified, defaults one will be used.

After creating a configuraiton and parameters the countrycrab.solver can be run with

p_vs_t, violated_constr_mat, inputs = solver.solve(config = config,params = params)

with p_vs_t a vector representing the solution probability as a function of iteration, violated_constr_mat the number of violated clauses as a funciton of iteration for each run, and inputs the optimized input for each run. Note that countrycrab.solver run on GPU(s) through CuPy calls, thus the available GPU(s) should be specified with

os.environ["CUDA_VISIBLE_DEVICES"]="0,1,2,3,4,5,6,7"

Scheduler usage

The scheduler takes a configuration, which usually contains multiple instances and parameters, and parallelize them in multiple processes with multiprocessing. ray is used to schedule the various experiments and 'mlflow' to track the result. An example of the scheduler usage is shown in tests/scheduler_usage.ipynb.

After creating a configuration file for the experiment, then the experiment is run with

python3 countrycrab/scheduler.py --tracking_uri=mlflow_tracking_uri --config=path_to_configuration_file

Footnotes

1. Pedretti, G., et al. "Zeroth and higher-order logic with content addressable memories." 2023 International Electron Devices Meeting (IEDM). IEEE, 2023. https://doig.org/10.1109/IEDM45741.2023.10413853 ↩