Appendix C.ProbesAs described in Section 6.9 Monitoring — , Monitoring-entitled systems can haveprobes applied to them that constantly confirm their health and full operability. Thisappendix lists the available probes broken down by command group, such as Apache.Many probes that monitor internal system aspects (such as the Linux::Disk Usage probe)rather than external aspects (such as the Network Services::SSH probe) require the instal-lation of the Red Hat Network Monitoring Daemon (rhnmd). This requirement is notedwithin the individual probe reference.Each probe has its own reference in this appendix that identifies required fields (markedwith *), default values, and the thresholds that may be set to trigger alerts. Similarly, thebeginning of each command group’s section contains information applicable to all probesin that group. Section C.1 Probe Guidelines covers general guidelines; the remaining sec-tions examine individual probes.NoteNearly all of the probes use Transmission Control Protocol (TCP) as their transport pro-tocol. Exceptions to this are noted within the individual probe references.C.1. Probe GuidelinesThe following general guidelines outline the meaning of each probe state, and provideguidance in setting thresholds for your probes.The following list provides a brief description of the meaning of each probe state:UnknownThe probes that cannot collect the metrics needed to determine probe state. Most(though not all) probes enter this state when exceeding their timeout period. Probes inthis state may be configured incorrectly, as well.PendingThe probes whose data has not been received by the RHN Satellite Server. It is normalfor new probes to be in this state. However, if all probes move into this state, yourmonitoring infrastructure may be failing.
