Bottleneckmon - Brocade Communications Systems 1606 Command Reference Manual

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bottleneckMon

bottleneckMon
Monitors and reports latency bottleneck conditions on F_Ports.
Synopsis bottleneckmon --enable [ -alert ] [-thresh threshold] [-time window] [-qtime quiet_time]
bottleneckmon --disable [slot ]/port_list [[slot ]port_list] ...
bottleneckmon --show [-interval interval ] [-span span_size] [slot/]port
bottleneckmon --status
bottleneckmon --help
Description Use this command to control the monitoring of latency bottlenecks on F_Ports, to enable and
configure alerts for detected bottlenecks, and to display statistics on bottleneck events on a
specified port. A latency bottleneck occurs when egress throughput at a port is lower than the
offered load because of latency in the return of credits from the other end of the link. This is not a
permanent condition. The load does not exceed the physical capacity of the channel as such, but
can occur because of an underperforming device connected to the fabric port. Bottleneck
monitoring can help identify these devices.
When bottleneck monitoring is enabled on a port and -alert is specified, the command triggers
RASLOG alerts when the port is experiencing latency depending on the configured alert
parameters. The command takes a sample every second to determine if the port is affected by a
latency bottleneck. You can configure a severity threshold and the time interval over which the
bottleneck is measured.
For example, setting a threshold of 0.8 and a time window of 30 seconds specifies that an alert
should be sent when 80% of the one-second samples over any period of 30 seconds were affected
by bottleneck conditions. The -qtime option can be used to throttle alerts by specifying the
minimum number of seconds between consecutive alerts.
The alerting parameters cannot be modified on a port where bottleneck detection is enabled. You
must first disable and then re-enable alerting with new parameters.
Bottleneck monitoring works both in non-Virtual Fabric mode and in Virtual Fabric Mode. If Virtual
Fabrics are enabled, bottleneck monitoring is configured per logical switch. If a port is removed
from a logical switch after bottleneck detection is enabled on the port, the configuration is retained
in that logical switch. If the port is added again to the same logical switch, bottleneck detection is
automatically re-enabled for this port using the retained configuration. This feature allows you to
configure more than one logical switch to perform bottleneck detection on the same port, although
only one logical switch performs the operation on the port at any given time.
The --show option displays a history of the bottleneck severity on the specified port. Each line of
output shows the percentage of one-second intervals affected by latency during the time window
shown on that line. The following information is displayed:
Alerts?
Threshold
Time (s)
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[slot/]port_list [[slot ]port_list] ...
Enabled (Y) or disabled (N).
The severity threshold for triggering an alert. This threshold indicates the
percentage of one-second intervals affected by the bottleneck condition
within a specified time window. The severity threshold is expressed as a
fraction between 0 and 1.
The time window in seconds over which the bottlenecking percentage is
computed and compared with the threshold.
Fabric OS Command Reference
53-1001337-01