- Helps developers create & maintain versions for their source code.
- Developers can collaborate on code & track changes
- Required for any development project.
gitis most commonly used.- Azure DevOps has Azure Repos that support
gitand Team Foundation Version Control. - Flow
- Each developer has their own copy
- They make changes
- Push their changes into central repository
- Other developers pull changes into their repositories
- If developer makes changes to same line of code it results in conflict.
- Other developers must resolve the conflict.
- Other solution: Locking
- Single developer locks a part of the code.
- Other developers cannot work on the locked part of the code.
- Git does not provide any locking functionality, since it is decentralized
git lfsthat's supported by some git providers like GitHub supports File Locking
- Centralized solutions such as SVN & ClearCase supports it.
- In a centralized repository like
SVNeveryone commits to a single repository.- If you lose server without backups, then everything is gone
- In a decentralized repository like
giteveryone commits to their own local copy (repository) of the remote repository and then pushes their changes to the remote repository.- You can work offline, as you don't need network to e.g. diff, check history, commit ,merge, switching branches, obtaining other revisions of a file
| name | type | license | description | Azure Repos support | Terminology |
|---|---|---|---|---|---|
| git | distributed | open-source | most popular, a lot tooling | ✔️ | pull & push |
| TFVC | centralized | proprietary | branches = paths, granular permissions down to a file level | ✔️ | check-in & check-out |
| mercurial | distributed | open-source | used by .eg. Facebook & Mozilla, simpler than GIT | ❌ | pull & push |
| svn (apache subversion) | centralized | open-source | branches = paths, granular permissions down to a file level | ❌ | commit & update |
| Helix Core (Perforce) | centralized | proprietary | branches = paths, granular permissions down to a file level | ❌ | check-in & check-out |
| ClearCase | centralized | proprietary | file-based architecture (where everything happens e.g. tagging at the file level) | ❌ |
- Git is distributed where each developer has own copy of the repository
- so who has the master?
- Many teams uses centralized Git model
- Possible to setup a Git server to host the repositories, but then maintenance is needed
- or there are e.g. GitHub, Atlassian, Azure Repos on internet.
- 💡 In Azure DevOps: Choose TFVC for granular permissions on branch (=path) level, otherwise use GIT.
- Types
- Main Only - commit your changes to the main branch and optionally indicate development and release milestones with tags
- ❗ The mutability and lack of history with TFVC labels can add risk of change control.
- Development isolation
- Have stable main branch, you can branch one or more dev branches from main
- Enables isolation and concurrent development
- Feature isolation
- Special derivation of the development isolation
- Branch one or more feature branches from main, as shown, or from your dev branches
- Release isolation
- Introduces one or more release branches from main
- Never forward integrate (FI) from main.
- Patches and hot fixes made to the release can be reverse integrated (RI) back to the main.
- Introduces one or more release branches from main
- Servicing and Release isolation
- Allows e.g. service packs
- release branch should never be modified
- Never forward integrate from main to servicing, and servicing to release.
- Altough not recommended, you can continue to evolve by introducing e.g. hotfix branches to releases=> Servicing, Hotfix, Release isolation
- Main Only - commit your changes to the main branch and optionally indicate development and release milestones with tags
