Organization is undoubtedly a critical component of large-scale development projects. In scenarios in which hundreds of people are working on the same project, a lack of management and coordination can have drastic implications on the project’s completion. By tracking and updating the changes every contributor makes to the ‘big picture,’ there is less room for error and more room for productivity and success. Every time someone goes to work on the project, they should know exactly what has already been completed, added, changed, and so on. Otherwise, they might end up working on something that’s already been finished – or worse, something that has no applicability to the project anymore.
Version control manages complex projects with many contributors. It is a means of tracking collaborative changes to a project so that each collaborator is constantly aware of, or has access to, the most recent state of the project. Any and all updates are recorded instantly by means of version control software (VCS) and consolidated so that the version of the project everyone has access to is as up-to-date and dynamic as possible.
In the context of software development, when a developer needs to save a new version of a project (or a file within the project), version control software will require them to write a short description of the changes they made to the file. This mandatory step forces developers to stay organized, whether they like it or not. Implementing version control, then, is a way of intentionally making sure that the completion of the project is smooth and does not run into any major organizational issues. After all, the process of managing hundreds (or even thousands!) of files and versions is much more troublesome and susceptible to errors than is the task of creating the project itself.
How does version control work?
Version control is executed in a rather straightforward fashion. The first step after setting up a version control system for your project is to specify the directory you want to be under version control. This is called a repository. You can check out a repository from a host, as would be the case with a distributed model of version control (explained later), or simply choose for the VCS which directories or files you want under version control. Most version control software operates within the confines of a number of user actions. Changes are tracked in bulk in most version control systems, so the developer submits their changes to the repository as a collection of actions called a commit. Commits are saved as changesets and titled with a revision that indicates the order that changes to the repository or file were made (e.g. an incrementally increasing number for each changeset). This nomenclature system prevents confusion and streamlines the process of reverting to previous versions, if necessary.
Individual users can request updates from the VCS in order to get the latest version of the project. To streamline the process, the VCS will only download changes that were made since your last request instead of updating the entire repository. As you make changes to files, the VCS will notify you if you are trying to overwrite another developer’s changes. Generally, the VCS will allow you to view the differences between your attempted edits and the recent revision that is causing the conflict. This is called diffing. You then have the option of overwriting the file or keeping the past revision. This feature in VCS is particularly useful in large teams, where overwriting can be a serious issue.
Two of the more powerful functions in version control are branching and merging. Together, they allow users to experiment on a project outside of its final version. Branching is an alternative to committing your changes in which the changes are not applied directly to the final version of the project. Instead, the VCS creates an amended copy of the repository, called a branch. It retains all the properties of the main repository (the trunk), but changes made to the branch do not get committed to the trunk. This is particularly useful when experimenting on something new that may not work out for the final version of the project – instead of committing the changes to the trunk and running the risk of having to ultimately revert to a previous version, you can safely work on it in a branch. Even better, modifications to the trunk can still be made while you have branches!
If a branch turns out to be a successful endeavor, you can merge it into the trunk. The VCS will ensure that there are no conflicts between the trunk and the branch being merged, and if there are, it will prompt the user to decide on the proper course of action. Merging is significant in that it allows branches to be completely separate from the trunk, while still being applicable to the overall project because of the ability to be merged, if necessary. For example, a developer can experiment within a branch to try to solve a bug without worrying about introducing errors to the main code file for everyone else. If they end up solving the bug fix, it can be merged to the trunk using version control, and therefore the branch had some applicability to the trunk.
What are the types of version control software?
There are a few major types of version control software, all of which are viable methods of implementing version control. The centralized model of version control works within a client-server paradigm, in which one centralized, localized repository is accessible by a number of clients. Popular version control systems like Subversion utilize this model for its simplicity and ease of use.
However, this model comes with disadvantages. VCS is entirely dependent on the functionality of a single server, which can reduce speed and the reliability of backups. The lack of reliability in this model is why many people prefer the distributed/decentralized model of version control. In the distributed model, all developers have their own local repository, and changes between repositories are implemented manually. GitHub and Mercurial utilize this model because it is faster and allows for reliable branching and merging.
Distributed systems of version control are generally less intuitive at first than centralized systems, but they can be much more powerful for those who understand how to use them. All accounted for, both models are very effective, but each one has its own advantages based on the specific requirements of a project.
Why is version control advantageous?
Consistency – VCS consolidates final projects into a single version. This level of consistency across all collaborators allows for increased productivity and less room for organizational mishaps. The one version of the project will always be the final version – you won’t waste your time comparing two files to find out which one is outdated.
Backups – Using VCS allows developers to have detailed information on the history of their projects, which is relevant in several ways. Version control software logs all the changes made to the project, so if you ever need a previous version, all you have to do is request it from your repository. The same functionality applies when you want to restore your project to a previous version.
Intentionality – A significant advantage of version control is the intentionality that it requires from its users. Whether making decisions about overwriting conflicts or managing the overall direction of a project, both developers and project managers are forced to be direct in their actions. To an extent, version control also promotes more careful work, since one person’s changes will directly and immediately affect everybody else.
Traceability – In version control, traceability is the ability to know the origin of changes to the repository (what, when, and by whom). It allows developers to look at a project from both very broad and very narrow perspectives. In the narrow sense, errors and bugs can be identified at the source via the meticulous documentation that version control requires of its users. In the broad sense, project managers can see how the project is evolving as a collective whole, which can help them make decisions as to future efforts and the ultimate direction of the project. Being able to see clearly how the project has evolved in the past, and how it is currently evolving, gives project managers the tools they need to steer it in the right direction.
Team dynamics – Version control makes it easier to work together as a cohesive team. Besides some obvious improvements in workflow and project direction, VCS allows developers to work independently on any file at the same time and merge everything together later. This means that concurrent file editing is allowed! Overwriting another developer’s changes is not an issue when working on a version control system, because it requires developers to resolve issues that arise when attempting to overwrite a recent change. Less confusion about file versions also results in less errors overall, because collaborators know exactly what they’re working with.
Communication – Particularly in software development, comments can be a significant form of communication between developers, especially when it is unclear what another team member’s intentions were when they last edited a file. Version control simplifies this by requiring commits to have a short description of what changed, why it changed, and who changed it.
Accountability – Within workplace dynamics, version control drives individual accountability. Seeing as every change – and every error – made by a person can be traced back to them, version control can motivate developers to be more thoughtful and careful about their work. Of course, this can also have detrimental effects in which the team is constantly blaming one another for mistakes, especially when there is no uncertainty as to whose oversight led to the mistake.
Open source platforms – Version control systems are particularly useful within open source platforms as well. Most notably, when several people make contributions to source code, it is valuable to know precisely who made which changes, and when. Even disputes over ownership and IP infringements can be solved with the objectivity and precision of version control. In this sense, version control is applicable on all scales – even open source projects in which changes can be made by any number of different users.
When you have hundreds of people working on the same project, keeping on top of management can be an enormous task, but with VCS, it is one you no longer have to worry about. Of course, though, it is important to keep in mind that version control is not a foolproof method of managing a project. While it is an extremely convenient and effective method of keeping your project organized, relying solely on a VCS to do all this can have its drawbacks.
For one, it reduces to some extent the intentionality of organizing a project which can make the process of completing it smoother. Using version control is not an opportunity to care less about the organization of a project, but rather a tool to care more about it. By making the management process easier and more automated, project managers can focus more on directing the project without worrying about tedious details. Poor utilization of version control can be just as detrimental to the project as it would be to use no VCS at all.
The benefits of version control software can make it a critical component of large-scale development projects. Keep in mind, VCS has value even on the individual level — keeping your own personal projects organized is just as important too!