System architecture

Helix TeamHub software is composed of popular and powerful open source technologies, which are used in today’s most advanced cloud solutions. The architecture is layered. Each component has its own role in serving user requests.

The entire stack is provided as a standalone native operating system package, also known as a Standard setup. Alternatively, the Helix TeamHub stack can be split into a number of servers, known as a Enterprise setup, and further expanded to a High Availability (HA) cluster. Regardless of the deployment type, the logical layers are as follows:

Proxy

Nginx proxy sits at front and handles all user requests. Based on the operation type (static page, version control system, or Web application) requests are forwarded to the appropriate component.

HTTP server

Helix TeamHub has three HTTP servers: Apache, Unicorn and Puma. Apache is responsible for handling version control operations, Unicorn serves Helix TeamHub Web applications, and Puma handles webSocket connections.

Application

Helix TeamHub consists of two major components. On the front end is Ember powered application responsible for providing UI to TeamHub APIs. The back end is powered by Ruby on Rails, which exposes RESTful APIs and the TeamHub Admin UI. It's important to note, TeamHub adheres to an API-first strategy. Any functionality seen in the TeamHub UI can be achieved programmatically with Helix TeamHub APIs.

Packages

Helix TeamHub relies on various open source packages that are bundled with TeamHub. Packages are precompiled for TeamHub supported operating systems, and are completely isolated from the rest of the system. Following are some of the packages bundled with TeamHub:

• Git, Subversion, Mercurial - TeamHub supported Version Control Systems.
• Resque - Handles background jobs.
• GraphicsMagick - Processes images uploaded to TeamHub.

Database

At the heart of the stack are the two NoSQL databases. MongoDB is used for storing application data. Redis keeps intermediate data, background jobs and events for example.

File system hierarchy

Helix TeamHub closely follows Linux File System Hierarchy Standard for its data and bundled packages. Here is the layout of the file system hierarchy TeamHub uses:

• /opt/hth The root folder for application and its dependencies.
• /opt/hth/bin The admin utilities and tools (see Helix TeamHub control).
• /var/opt/hth/shared The data directory with all user data, such as repositories and uploads.
• /var/opt/hth/db The database directory.
• /var/opt/hth/backups The directory where backups are stored.
• /var/log/hth Application and system logs.

For a detailed list of system-wide configuration files that TeamHub touches, see System overrides.