Bottleneckmon - Brocade Communications Systems 8 Command Reference Manual

bottleneckMon

Monitors and reports latency and congestion bottlenecks on F_Ports and E_Ports.
Synopsis bottleneckmon --enable [ -cthresh congestion_threshold] [-lthresh latency_threshold] [
bottleneckmon --disable
bottleneckmon --config [-cthresh congestion_threshold] [-lthresh latency_threshold]
bottleneckmon --configclear [slot]port_list
bottleneckmon --exclude [slot]port_list
bottleneckmon --include [slot]port_list
bottleneckmon --show [-interval seconds] [-span seconds] [-refresh]
bottleneckmon --status
bottleneckmon --help
Description Use this command to monitor latency and congestion bottlenecks on F[L]_Ports and E_Ports. The
configuration options supported by this command include the following management functions:
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In Fabric OS v6.4.0 and later, enabling or disabling bottleneck monitoring is a switch-wide
operation. If Virtual Fabrics are enabled, the configuration is applied per logical switch and affects
all ports on the current logical switch. After the (logical) switch-wide bottleneck monitoring
parameters have been set, you can you can fine-tune the configuration for specific ports.
A bottleneck is defined as a condition where the offered load at a given port exceeds the
throughput at the port. This command supports detection of two types of bottleneck conditions:
congestion and latency.
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Fabric OS Command Reference
53-1001764-02
-time seconds] [-qtime seconds] [-alert | -noalert]
[-time seconds][-qtime seconds] [[slot]port_list] [-alert | -noalert]
[-congestion | -latency ] [[slot/]port | *]
Enabling or disabling bottleneck monitoring on a switch and optionally configuring thresholds
and alert parameters.
Changing alert parameters on specified ports after you have enabled the feature on the switch.
Configuring severity thresholds for congestion and latency bottlenecks for a switch or for a
specified port list.
Clearing the configuration on specified ports only (this option cannot be performed
switch-wide).
Excluding specified ports from being monitored or including previously excluded ports.
Generating history or status reports that show congestion bottlenecks and latency bottlenecks.
A congestion bottleneck arises from link over-utilization. This happens when the offered load
exceeds throughput and throughput is at 100%. Frames attempt to egress at a faster rate than
the line rate allows. Link utilization is measured once every second at the port (or when
trunked ports are monitored at the trunk master). A congestion bottleneck is assumed if the
utilization during the measured second is 95% or more.
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 offered load exceeds throughput and throughput is less than 100%.
In this case, the load does not exceed the physical capacity of the channel as such, but can
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