Chapter 13. Maintaining Jenkins
In this chapter, we will be discussing a few tips and tricks that you might find useful when maintaining a large Jenkins instance. We will look at things like how to limit, and keep tabs on, disk usage, how to give Jenkins enough memory and how to archive build jobs or migrate them from one server to another. Some of these topics are discussed elsewhere in the book, but here we will be looking at things from the point of view of the system administrator.
Monitoring Disk Space
Build History takes disk space. In addition, Jenkins analyzes the build records when it loads a project configuration, so a build job with a thousand archived builds is going to take a lot longer to load than one with only fifty. If you have a large Jenkins server with tens or hundreds of build jobs, multiply this accordingly.
Probably the simplest way to keep a cap on disk usage is to limit the number of builds a project maintains in its history. You can configure this by ticking the Discard Old Builds checkbox at the top of the project configuration page (see Figure 13-1). If you tell Jenkins to only keep the last 20 builds, it will start discarding (and deleting) older build jobs once it reaches this number. You can limit them by number (i.e., no more than 20 builds) or by date (i.e., builds no older than 30 days). It does this intelligently, though: if there has ever been a successful build, Jenkins will always keep at least the latest successful build as part of ...