HP Fabric OS v7.0.1, Administrator'S Manual

Page: 337 / 584

Fabric OS Administrator’s Guide 299
53-1002446-01
Bottleneck detection overview
13
•
How many affected seconds are needed to generate the alert.
•
How long to stay quiet after an alert
Changing alerting parameters affects RASlog alerting as well as SNMP traps.
Using alerting parameters to determine whether alerts are generated
You have the option of receiving per-port alerts based on the latency and congestion history of the
port. Alerts are generated based on the number of affected seconds over a specified period of
time. If the number of affected seconds is higher than the threshold, an alert is generated. This
process is done independently for latency and congestion.
The bottleneckmon alerting parameters determine whether an alert is generated.
For example, Figure 48 shows an interval of 12 seconds, in which 6 seconds are affected by a
congestion bottleneck and 3 seconds are affected by a latency bottleneck.
FIGURE 48
Affected seconds for bottleneck detection
The -time parameter specifies the time window. For this example, -time = 12 seconds.
The -cthresh and -lthresh parameters specify the thresholds on number of affected seconds that
trigger alerts for congestion and latency bottlenecks, respectively. For this example, assume the
default values for these parameters:
•
-cthresh = 0.8 (80%)
•
-lthresh = 0.1 (10%)
For this time window, 50% of the seconds (6 out of 12 seconds) are affected by congestion. This is
below the threshold of 80%, so an alert would not be generated for a congestion bottleneck.
For the same time window, 25% of the seconds (3 out of 12 seconds) are affected by latency. This
exceeds the threshold of 10%, so an alert would be generated for a latency bottleneck.
Time (seconds)
Affected by congestion bottleneck?
Yes
No
0 1 2 3 4 5 6 7 8 9 10 11 12
Time (seconds)
Affected by latency bottleneck?
0 1 2 3 4 5 6 7 8 9 10 11 12