Chapter 8.151MonitoringThe Red Hat Network Monitoring entitlement allows you to perform a whole host of actions designedto keep your systems running properly and efficiently. With it, you can keep close watch on systemresources, network services, databases, and both standard and custom applications.Monitoring provides both real-time and historical state-change information, as well as specific metricdata. You are not only notified of failures immediately and warned of performance degradation beforeit becomes critical, but you are also given the information necessary to conduct capacity planning andevent correlation. For instance, the results of a probe recording CPU usage across systems wouldprove invaluable in balancing loads on those systems.Monitoring entails establishing notification methods, installing probes on systems, regularly reviewingthe status of all probes, and generating reports displaying historical data for a system or service.This chapter seeks to identify common tasks associated with the Monitoring entitlement. Remember,virtually all changes affecting your Monitoring infrastructure must be finalized by updating yourconfiguration, through the Scout Config Push page.8.1. PrerequisitesBefore attempting to implement RHN Monitoring within your infrastructure, ensure you have all of thenecessary tools in place. At a minimum, you need:• Monitoring entitlements — These entitlements are required for all systems that are to be monitored.Monitoring is supported only on Red Hat Enterprise Linux systems.• RHN Satellite with Monitoring — Monitoring systems must be connected to a Satellite with a baseoperating system of Red Hat Enterprise Linux AS 4, Red Hat Enterprise Linux 5 or later. Refer to theRHN Satellite Installation Guide within Help for installation instructions.• Monitoring Administrator — This role must be granted to users installing probes, creating notificationmethods, or altering the monitoring infrastructure in any way. (Remember, the Satellite Administratorautomatically inherits the abilities of all other roles within an organization and can therefore conductthese tasks.). Assign this role through the User Details page for the user.• Red Hat Network Monitoring Daemon — This daemon, along with the SSH key for the scout, isrequired on systems that are monitored in order for the internal process monitors to be executed.You may, however, be able to run these probes using the systems' existing SSH daemon (sshd).Refer to Section 8.2, “Red Hat Network Monitoring Daemon (rhnmd)” for installation instructions anda quick list of probes requiring this secure connection. Refer to Appendix D, Probes for the completelist of available probes.8.2. Red Hat Network Monitoring Daemon (rhnmd)To get the most out of your Monitoring entitlement, Red Hat suggests installing the Red Hat NetworkMonitoring Daemon on your client systems. Based upon OpenSSH, rhnmd enables the RHN Satelliteto communicate securely with the client system to access internal processes and retrieve probe status.Please note that the Red Hat Network Monitoring Daemon requires that monitored systems allowconnections on port 4545. You may avoid opening this port and installing the daemon altogether byusing sshd instead. Refer to Section 8.2.3, “Configuring SSH” for details.
