Continua CI has been built with a distributed architecture in mind, which grows as your development workload increases. Continua CI consists of one Server which controls and directs the build workflow, and multiple agents that are responsible for building and running actions. By default, Continua CI will install an agent on the Continua Server so right from the start there will always be at least one agent available to Continua CI.
Continua's distributed architecture only comes into effect once extra concurrent builds have been added to your Continua CI license. There is only one version of Continua so no matter which price plan you are currently on, you will always have a fully functioning copy of Continua CI. Where the different price plans differ however is the number of concurrent builds and agents that can be associated with Continua CI. Continua's distributed architecture is only available to users that have installed additional build licenses as Continua's free license only allows users to run 1 build at a time and this will always be run on the agent installed locally on the Continua server.
Server & Agent Architecture
Continua CI's distributed architecture is based around the idea that the Continua Server will distribute the workload to all the Continua agents. Once a build has begun, the server gets the first stage in the current build and executes the following workflow:
- The server checks all the actions in current stage and picks the next available agent that can run all the actions.
- The server sends all the required information to the agent including repositories, variables, files and actions.
- The agent then steps through and executes each action in the stage.
- The agent sends all the designated information back to the server.
- The server moves onto the next stage and begins the workflow again.
Figure 1. Continua's server and agent architecture
Single Build over multiple agents