Understanding the master and slave architecture

A standalone Jenkins instance can grow fairly quickly into a disk-munching, CPU-eating monster. To prevent this from happening, we can scale Jenkins by implementing a slave node architecture, which can help us offload some of the responsibilities of the master Jenkins instance. Let's clarify this concept. A Jenkins slave node is simply a device configured to act as an automation executor on behalf of the master. The Jenkins master simply represents the base installation of Jenkins. The master will continue to perform basic operations and serve the user interface, while the slaves do the heavy lifting.

This distributed computing model will allow the Jenkins master to remain responsive to users, while offloading automation execution to the connected slave(s). To illustrate the concept of a master, and slave mode architecture let's look at an example. Figure 2-1 shows a Jenkins master and three slave nodes of varying OS types:

Figure 2-1: A Jenkins...