cppGFS2.0

A distributed Google File System (GFS), implemented in C++

Demo

• Presentation Slide
• Demo Video
• Our Paper

Getting Started

In this project, we plan to use Bazel as our main build tool. You can install Bazel by following their website instructions.

As of writing, you will need at least Bazel version 5.1.0 for a proper working demo.

Installation scripts have been provided to install bazel in scripts folder.

For example, for Linux, run with desired Bazel version:

export BAZEL_VERSION=5.1.0
chmod +x scripts/install_bazel_linux_x86_64.sh
scripts/install_bazel_linux_x86_64.sh

For MacBook (Intel Chip), use scripts/install_bazel_darwin_x86_64.sh.

For MacBook (Apple Chips), use scripts/install_bazel_darwin_arm64.sh.

Then, from the root directory, you can run Bazel commands as normal. For example:

bazel build ...
bazel test --test_output=errors ...

To learn more about how to use Bazel, or how to write Bazel build rule for C++, see the official documentation.

Note: If you get an error in the form of illegal thread local variable reference to regular symbol, try adding --features=-supports_dynamic_linker to your Bazel build flags. For example, bazel build --features=-supports_dynamic_linker ....

Running GFS client

Make sure you have the GFS server clusters are up and running.

You can either write a binary by importing the GFS client at src/client/gfs_client.h, or using the GFS command line binary.

To build the command line binary, run

bazel build :gfs_client_main

Then, you can run any of these modes:

# To create a file
bazel-bin/gfs_client_main --mode=create --filename=/test

# To read a file
bazel-bin/gfs_client_main --mode=read --filename=/test --offset=0 --nbytes=100

# To write a file
# This will create the file if it doesn't exist; if you don't want this behavior,
# use the 'write_no_create' mode instead
bazel-bin/gfs_client_main --mode=write --filename=/test --offset=0 --data='Hello World!'

Running GFS server clusters using Docker

Make sure you have Docker and Docker compose installed

To start all servers and expose respective server ports outside of Docker for connection, run:

docker-compose up --build

As of writing, the Dockerfile doesn't support MacBook M1 Max yet. You will need to manually update the file to install/use a ARM64 compatible Bazel image. You can refer to the scripts folder for installation instructions.

Then, you can use GFS client to interact with the cluster.

After you are done with it, turn everything off by typing Ctrl + C, and then

docker-compose down

Benchmark Performance

We use Google Benchmarks open source library to test our performance.

To run them, simply start the GFS cluster in the background, and run the benchmark binaries in src/benchmarks

Known Issues

• If the initialization of the first file chunk fails at any of the chunk server during file creation, the metadata will be created but chunks won't be initialized, so future file creation on the same filename fails, and file read/write will use inconsistent chunk server locations
• We do not bring stale replica up to date, at the moment

C++ Style Guide

Please, if possible, follow Google C++ style guide. If you use an IDE or any common text editors, they have extensions that help you auto format and lint your code for style errors.