If you tick the “Disable automatic artifact archiving” checkbox here, Jenkins will refrain from storing the
jar files your project build generates. This is a good way of making your friendly system administrator
happy.
Note that sometimes you do need to store the Maven artifacts. For example, they often come in handy
when implementing a build pipeline (see Section 10.7, “Build Pipelines and Promotions”). In this case,
you can always choose to archive the artifacts you need manually, and then use the “Discard old builds”
option to refine how long you keep them for.
13.3. Monitoring the Server Load
Jenkins provides build-in monitoring of server activity. On the Manage Jenkins screen, click on the
Load Statistics icon. This will display a graph of the server load over time for the master node (see
Figure 13.7, “Jenkins Load Statistics”). This graph keeps track of three metrics: the total number of
executors, the number of busy executors, and queue length.
The total number of executors (the blue line) includes the executors on the master and on the
slave nodes. This can vary when slaves are brought on and offline, and can be a useful indicator of how
well your dynamic provisioning of slave nodes is working.
The number of busy executors (the red line) indicates how many of your executors are occupied
executing builds. You should make sure you have enough spare capacity here to absorb spikes in
build jobs. If all of your executors are permanently occupied running build jobs, you should add more
executors and/or slave nodes.
The queue length (the gray line) is the number of build jobs awaiting executing. Build jobs are queued
when all of the executors are occupied. This metric does not include jobs that are waiting for an upstream
build job to finish, so it gives a reasonable idea of when your server could benefit from extra capacity.