Dell EMC SmartFabric OS10 User Guide Release 10.5.0

Buffer statistics tracking

OS10 offers the Buffer Statistics Tracking (BST) feature to observe buffer usage across the switch without any impact to performance. This feature maintains separate sets of counters for buffer usage accounting:

• Ingress priority-group
• Ingress service-pool
• Ingress shared-headroom-pool
• Egress queue
• Egress service-pool

You can obtain a snapshot of the buffer statistics for the different buffer objects, such as a snapshot of all ingress priority-groups associated to a port, all egress unicast queues bound to a port, and so on.

You can enable BST at the global level. OS10 tracks buffer utilization and provides the maximum peak statistics value over a period of time and the current value of the monitored BST counter.

Use the buffer-statistics-tracking command in SYSTEM-QOS mode to enable BST:

OS10# configure terminal
OS10(config)# configure system-qos
OS10(config-sys-qos)# buffer-statistics-tracking

Clear the counter

You can choose to reset the peak buffer utilization value and determine a new peak buffer utilization value. Use the clear qos statistics type buffer-statistics-tracking command to clear the tracked value and to refresh this counter.

BST tracks peak buffer utilization over a period of time. At any given point in time, the peak buffer usage from the past is displayed.

For example, if you enable BST at time T0 and use the show command to view the peak buffer utilization value at time T1, the peak usage between T0 and T1 is displayed. If you view the peak buffer utilization again at time T2, the peak usage between T0 and T2 is displayed. However, if you clear the counter using the clear qos statistics type buffer-statistics-tracking command at time T3 and view the peak buffer utilization at time T4, the peak usage between T3 and T4 is displayed.

Advantages of BST include:

• Detecting microburst congestions
• Monitoring buffer utilization and historical trends
• Determining optimal sizes and thresholds for the ingress or egress shared buffers and headroom on a given port or queue based on real-time data

After you disable BST, be sure to clear the counter using the clear qos statistics type buffer-statistics-tracking command.