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 its build history, so you will never loose your last successful build.
Figure 13-1. Discarding old builds
The problem with discarding old builds is that you loose the build history at the same time. Jenkins uses the build records to produce graphs of test results and build metrics. If you limit the number of builds to be kept to twenty, for example, Jenkins will only display graphs containing the last ...