cįigure 2 reports the number of unique human committers per week to the main repository, January 2010-July 2015. Most of this traffic originates from Google's distributed build-and-test systems. Each day the repository serves billions of file read requests, with approximately 800,000 queries per second during peak traffic and an average of approximately 500,000 queries per second each workday. On a typical workday, they commit 16,000 changes to the codebase, and another 24,000 changes are committed by automated systems.
SOURCETREE APP MASSIVE SOFTWARE
Google's codebase is shared by more than 25,000 Google software developers from dozens of offices in countries around the world.
SOURCETREE APP MASSIVE CODE
The Linux kernel is a prominent example of a large open source software repository containing approximately 15 million lines of code in 40,000 files. In 2014, approximately 15 million lines of code were changed b in approximately 250,000 files in the Google repository on a weekly basis. The total number of files also includes source files copied into release branches, files that are deleted at the latest revision, configuration files, documentation, and supporting data files see the table here for a summary of Google's repository statistics from January 2015. The repository contains 86TB a of data, including approximately two billion lines of code in nine million unique source files. The Google codebase includes approximately one billion files and has a history of approximately 35 million commits spanning Google's entire 18-year existence. Google's monolithic software repository, which is used by 95% of its software developers worldwide, meets the definition of an ultra-large-scale 4 system, providing evidence the single-source repository model can be scaled successfully. We explain Google's "trunk-based development" strategy and the support systems that structure workflow and keep Google's codebase healthy, including software for static analysis, code cleanup, and streamlined code review. Here, we provide background on the systems and workflows that make feasible managing and working productively with such a large repository. This centralized system is the foundation of many of Google's developer workflows. Google uses a homegrown version-control system to host one large codebase visible to, and used by, most of the software developers in the company. This article outlines the scale of that codebase and details Google's custom-built monolithic source repository and the reasons the model was chosen. As a result, the technology used to host the codebase has also evolved significantly. Meanwhile, the number of Google software developers has steadily increased, and the size of the Google codebase has grown exponentially (see Figure 1). This approach has served Google well for more than 16 years, and today the vast majority of Google's software assets continues to be stored in a single, shared repository. Credit: Iwona Usakiewicz / Andrij Borys AssociatesĮarly Google employees decided to work with a shared codebase managed through a centralized source control system.