Brocade Fabric Watch Administrator's Guide - Supporting Fabric OS v5.3.0 (53-1000438-01, June 2007)

Fabric Watch Administrator’s Guide 17
53-0000438-01
Configuring events
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the high threshold (event 1 in Figure 6). When the data value becomes less than the high threshold
and buffer value, Fabric Watch triggers a second event (Event 2) to indicate that it has returned to
normal operation. The second event will not be triggered until the counter value falls below the high
threshold and buffer values.
FIGURE 6 Above event trigger with buffer zone
Below event trigger
The Below event trigger generates an event when a data value becomes less than the low
threshold boundary.
When a buffer is defined, the event will be triggered when the value goes below the lower
threshold. A second event will not be generated until the value crosses the buffer region set above
the lower threshold.
Changed event trigger
Use the Changed event trigger for an element that requires “rate of change” monitoring. When
Fabric Watch detects a change in the counter value between two sample periods (defined by the
time base), it triggers an event regardless of high or low threshold settings. Figure 7 shows events
generated when the data value changes. Each arrow in the figure indicates a generated event.
FIGURE 7 Changed threshold
Use Changed event triggers with discretion. They are most useful when a change in value is
expected to be rare. Monitoring a fabric element that is subject to frequent change generates so
many events that it can render it virtually useless. For example, this trigger type is appropriate for
FRU failures. It is not appropriate for temperature monitoring.