44a352e8e3
Summary: When there is an issue in the import process, there is not an easy way to detect this currently. As a first step towards making it possible to detect when there is an issue here, we expose the number if imports pending to `eden top`. If there is a problem blocking imports from happening, then they will start to queue up and the number of pending imports will keep growing. When there are a lot of pending imports it indicates that there may be a problem in the import process. note: there are cases when there are many pending imports under normal operation. It is common to batch fetch a bunch of files at once, and submitting all these prefetches at once will mean a lot of pending imports though there is no problem. Thus number of pending imports only indicates there *may* be an issue in the import process. (Thus we couple it with the duration of the longest import D20627754 for stronger signal) The other value in showing the number of pending imports is giving users more transparency into eden. When there is a big batch of imports this may leave the user waiting a while, and this gives a way for them to know why. They can see that eden is making progress rather than being stuck. Reviewed By: fanzeyi Differential Revision: D20527273 fbshipit-source-id: 59e0fdff6e7b154b409dfab385b4fdb02062b066 |
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| .github/workflows | ||
| build | ||
| CMake | ||
| common | ||
| eden | ||
| .gitignore | ||
| .projectid | ||
| .travis.yml | ||
| build.bat | ||
| build.sh | ||
| CMakeLists.txt | ||
| CODE_OF_CONDUCT.md | ||
| CONTRIBUTING.md | ||
| LICENSE | ||
| make-client.py | ||
| README.md | ||
| rustfmt.toml | ||
EdenSCM
EdenSCM is a cross-platform, highly scalable source control management system.
It aims to provide both user-friendly and powerful interfaces for users, as well as extreme scalability to deal with repositories containing many millions of files and many millions of commits.
EdenSCM is comprised of three main components:
- The
edenCLI: The client-side command line interface for users to interact with EdenSCM. - Mononoke: The server-side part of EdenSCM.
- EdenFS: A virtual filesystem for efficiently checking out large repositories.
EdenSCM's scalability goals are to ensure that all source control operations scale with the number of files in use by a developer, and not with the size of the repository itself. This enables fast, performant developer experiences even in massive repositories with many long files and very long commit histories.
The eden CLI
The eden CLI was originally based on
Mercurial, and shares many aspects of the UI
and features of Mercurial.
The CLI code can be found in the eden/scm subdirectory.
Building the eden CLI
The eden CLI currently builds and runs on Linux, Mac, and Windows. The
setup.py script is the main interface for building the CLI.
Mononoke
Mononoke is the server-side component of EdenSCM.
Despite having originally evolved from Mercurial, EdenSCM is not a distributed source control system. In order to support massive repositories, not all repository data is downloaded to the client system when checking out a repository. Clients ideally only download the minimal amount of data necessary, and then fetch additional data from the server as it is needed.
Building Mononoke
The Mononoke code lives under eden/mononoke
Mononoke currently builds and runs only on Linux, and is not yet buildable
outside of Facebook's internal environment. Work is still in progress to
support building Mononoke with Rust's cargo build system.
EdenFS
EdenFS is a virtual file system for managing EdenSCM checkouts.
EdenFS speeds up operations in large repositories by only populating working
directory files on demand, as they are accessed. This makes operations like
checkout much faster, in exchange for a small performance hit when first
accessing new files. This is quite beneficial in large repositories where
developers often only work with a small subset of the repository at a time.
EdenFS has similar performance advantages to using sparse checkouts, but a much better user experience. Unlike with sparse checkouts, EdenFS does not require manually curating the list of files to check out, and users can transparently access any file without needing to update the profile.
EdenFS also keeps track of which files have been modified, allowing very
efficient status queries that do not need to scan the working directory.
The filesystem monitoring tool Watchman
also integrates with EdenFS, allowing it to more efficiently track updates to
the filesystem.
Building EdenFS
EdenFS currently builds on Linux, Mac, and Windows.
The recommended way to build EdenFS is using the build.sh script in the
top-level of the repository. This script will download and build all of the
necessary dependencies for EdenFS, before building EdenFS itself. On Windows
use the build.bat script instead of build.sh.
This build script will create an output directory outside of the repository
where it will perform the build. You can control this output directory
location by passing a --scratch-path argument to the build script.
Support
EdenSCM is the primary source control system used at Facebook, and is used for Facebook's main monorepo code base.
Support for using EdenSCM outside of Facebook is still highly experimental. While we would be interested to hear feedback if you run into issues, supporting external users is not currently a high priority for the development team, so we unfortunately cannot guarantee prompt support at this time.
License
See LICENSE.