Distributed Version Control System (DVCS)
A Distributed Version Control System (DVCS) is a Version Control System that enables multiple users to simultaneously work on a codebase, with changes merged and maintained in a distributed manner across multiple repositories.
- AKA: Distributed Revision Control System, Distributed Source Control System.
- Context:
- It can solve distributed version control tasks (in which the complete codebase, including its full change history, is mirrored on every software developer's computer).
- It distributes the full history of the repository to each user’s computer, allowing operations such as commits, branches, and merges to be performed locally, thereby decentralizing the control over the source code.
- It can store complete copies of a project’s repository on each developer’s machine, which inherently serves as a backup and reduces dependency on a central server.
- It can enable developers to work offline and synchronize changes with other team members later, enhancing flexibility in development environments.
- It can perform operations like branching and merging more quickly since these actions don't require communication with a central server.
- It can encourage collaboration through pull requests or merge requests, where changes are reviewed before being integrated into the main project.
- It can increase security concerns as each developer has a full copy of the project’s repository, raising the stakes for managing sensitive data securely.
- …
- Example(s):
- Counter-Example(s):
- See: Centralized Version Control System, Codebase, Branching (Version Control), Merge (Version Control), Client-Server Model, Distributed Content Management System, Repository, Source Code Management (SCM) System, Code Collaboration.
References
2024a
- (Wikipedia, 2024) ⇒ https://en.wikipedia.org/wiki/Distributed_version_control Retrieved:2024-4-14.
- In software development, distributed version control (also known as distributed revision control) is a form of version control in which the complete codebase, including its full history, is mirrored on every developer's computer. Compared to centralized version control, this enables automatic management branching and merging, speeds up most operations (except pushing and pulling), improves the ability to work offline, and does not rely on a single location for backups. Git, the world's most popular version control system,is a distributed version control system.
In 2010, software development author Joel Spolsky described distributed version control systems as "possibly the biggest advance in software development technology in the [past] ten years".
- In software development, distributed version control (also known as distributed revision control) is a form of version control in which the complete codebase, including its full history, is mirrored on every developer's computer. Compared to centralized version control, this enables automatic management branching and merging, speeds up most operations (except pushing and pulling), improves the ability to work offline, and does not rely on a single location for backups. Git, the world's most popular version control system,is a distributed version control system.
2024b
- (ChatGPT-OpenAI, 2024) ⇒ Prompt: Summarize the concept Distributed Version Control System (DVCS) in 1- 2 paragraphs. ChatGPT (model:gpt-4-turbo-preview). Retrieved: 2024-04-14.
- QUOTE: A Distributed Version Control System (DVCS), such as Git or Mercurial, is an advanced approach to version control that allows multiple developers to work more efficiently and independently on a project. Unlike centralized version control systems where a single repository on a server is the focal point for all changes, in a DVCS, each contributor maintains a personal copy of the entire repository, including its full history of changes. This means that every clone of the repository is a full backup, which enhances collaboration and significantly improves data integrity and disaster recovery processes.
The decentralized nature of DVCS enables developers to work offline, commit changes, create branches, and merge updates locally before sharing their changes with the rest of the team. This proves particularly useful in fostering parallel development, allowing for isolated environments for features or bug fixes without affecting the main project. Once a developer is ready to share their work, they can push their changes to a shared server, from where others can pull updates. The inherent flexibility and robustness of DVCS systems facilitate a more dynamic development workflow, improve productivity, and support complex project hierarchies more effectively than their centralized counterparts.
- QUOTE: A Distributed Version Control System (DVCS), such as Git or Mercurial, is an advanced approach to version control that allows multiple developers to work more efficiently and independently on a project. Unlike centralized version control systems where a single repository on a server is the focal point for all changes, in a DVCS, each contributor maintains a personal copy of the entire repository, including its full history of changes. This means that every clone of the repository is a full backup, which enhances collaboration and significantly improves data integrity and disaster recovery processes.
2024c
- (GitLab, 2024) ⇒ https://about.gitlab.com/topics/version-control/benefits-distributed-version-control-system/ Retrieved:2024-4-14.
- QUOTE:A distributed version control system (DVCS) brings a local copy of the complete repository to every team member’s computer, so they can commit, branch, and merge locally. The server doesn’t have to store a physical file for each branch — it just needs the differences between each commit.
Distributed source code management systems, such as Git, Mercurial, and Bazaar, mirror the repository and its entire history as a local copy on individual hard drives.
Distributed version control systems help software development teams create strong workflows and hierarchies, with each developer pushing code changes to their own repository and maintainers setting a code review process to ensure only quality code merges into the main repository.
A DVCS can be puzzling, especially if a team member is accustomed to centralized source code systems, because a contributor can no longer rely on a server to resolve conflicts when merging and has to resolve them locally, which can result in confusing merge commits. However, despite the initial discomfort, a distributed source control system can ensure stable code development when multiple developers contribute to software development projects.
- QUOTE:A distributed version control system (DVCS) brings a local copy of the complete repository to every team member’s computer, so they can commit, branch, and merge locally. The server doesn’t have to store a physical file for each branch — it just needs the differences between each commit.
2012
- (Lionetti, 2012) ⇒ Giancarlo Lionetti (2012). "Centralized vs. Distributed Version Control". In: Atlassian Documentation.
- QUOTE: In the past five years or so a new breed of tools has appeared: so-called “distributed” version control systems (DVCS for short). The three most popular of these are Mercurial, Git and Bazaar.
These systems do not necessarily rely on a central server to store all the versions of a project’s files. Instead, every developer “clones” a copy of a repository and has the full history of the project on their own hard drive. This copy (or “clone”) has all of the metadata of the original.
This method may sound wasteful, but in practice, it’s not a problem. Most programming projects consist mostly of plain text files (and maybe a few images), and disk space is so cheap that storing many copies of a file doesn’t create a noticable dent in a hard drive’s free space. Modern systems also compress the files to use even less space.
The act of getting new changes from a repository is usually called “pulling,” and the act of moving your own changes to a repository is called “pushing”. In both cases, you move changesets (changes to files grouped as coherent wholes), not single-file diffs.
One common misconception about distributed version control systems is that there cannot be a central project repository. This is simply not true – there is nothing stopping you from saying “this copy of the project is the authoritative one.” This means that instead of a central repository being required by the tools you use, it is now optional and purely a social issue.
- Advantages Over Centralized Version Control
The act of cloning an entire repository gives distributed version control tools several advantages over centralized systems:
- Performing actions other than pushing and pulling changesets is extremely fast because the tool only needs to access the hard drive, not a remote server.
- Committing new changesets can be done locally without anyone else seeing them. Once you have a group of changesets ready, you can push all of them at once.
- Everything but pushing and pulling can be done without an internet connection. So you can work on a plane, and you won’t be forced to commit several bugfixes as one big changeset.
- Since each programmer has a full copy of the project repository, they can share changes with one or two other people at a time if they want to get some feedback before showing the changes to everyone.
- Disadvantages Compared to Centralized Version Control
To be quite honest, there are almost no disadvantages to using a distributed version control system over a centralized one. Distributed systems do not prevent you from having a single “central” repository, they just provide more options on top of that.
There are only two major inherent disadvantages to using a distributed system:
- If your project contains many large, binary files that cannot be easily compressed, the space needed to store all versions of these files can accumulate quickly.
- If your project has a very long history (50,000 changesets or more), downloading the entire history can take an impractical amount of time and disk space.
The authors and contributors of modern distributed version control systems are working on solving these problems, but at the moment, no bundled, built-in features solve them.
- QUOTE: In the past five years or so a new breed of tools has appeared: so-called “distributed” version control systems (DVCS for short). The three most popular of these are Mercurial, Git and Bazaar.