HP StorageWorks 2/16V Brocade Fabric Watch Administrator's Guide - Supporting - Page 34

1 Port persistence In-between event triggers Fabric Watch event triggers are usually set to notify the user of a warning or failure condition, but there is an exception. You can define the In-Between event trigger to receive a notification of fault recovery. For example, when measuring port performance, crossing the high threshold triggers an Above threshold event, which displays a warning message. The threshold might be crossed for a period so brief that is not a true cause for an alarm. An In-Between event trigger indicates that the port performance has returned to the acceptable range. Use the In-Between event trigger to: - Verify a successful recovery from a faulty condition. - Reset the counter value for the next event. - Identify an element that is consistently operating under marginal condition. Figure 8 illustrates event notification using an In-Between event trigger. The arrow marked with one indicates the point at which event notification occurs. FIGURE 8 In-between event trigger Fabric Watch alarm behavior Fabric Watch alarm behavior depends on the threshold states associated with the Above, Below and Changed thresholds. Threshold states can be INFORMATIVE, IN_RANGE, and OUT_OF_RANGE. Alarms are generated only for the following transitions: • IN_RANGE to OUT_OF_RANGE An alarm is generated • OUT_OF_RANGE to IN_RANGE An alarm is generated No alarm is generated for INFORMATIVE to IN_RANGE (or IN_RANGE to INFORMATIVE) See Appendix , "Default Threshold Values" for more details about the threshold states for Above, Below, and Changed. Port persistence The data collected in port monitoring can vary a great deal over short time periods. Therefore, the port can become a source of frequent event messages (the data can exceed the threshold range and return to a value within the threshold range). 18 Fabric Watch Administrator's Guide 53-0000438-01