qos queue drr
Function
The qos queue drr command sets the WDRR weight of queues that participate in WDRR scheduling.
The undo qos queue drr command restores the default WDRR weight of queues that participate in WDRR scheduling.
By default, the WDRR weight of queues that participate in WDRR scheduling is 1.
Only the S5720-EI, S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S5735-L, S5735S-L, S5735S-L-M, S5735-S, S5735S-S, S5735-S-I, S6720-EI, S6720-HI, S6720S-EI, S6730-H, S6730S-H, S6730-S, and S6730S-S support this command in interface mode.
Only the S2720-EI, S5720I-SI, S5720-LI, S5720S-LI, S5720S-SI, S5720-SI, S5730S-EI, S5730-SI, S6720-LI, S6720S-LI, S6720S-SI, and S6720-SI support this command using a schedule template.
Parameters
Parameter |
Description |
Value |
|---|---|---|
queue-index |
Specifies the index of a queue. |
The value is an integer that ranges from 0 to 7. |
weight weight |
Specifies a WDRR weight. |
The value is an integer. The value range is as follows:
|
Views
GE interface view, XGE interface view, 25GE interface view, MultiGE interface view, 40GE interface view, 100GE interface view, port group view, Scheduling profile view
Usage Guidelines
Usage Scenario
WDRR schedules packets based on the packet length used as the weight. If the packet length is too long, WDRR allows the negative weight value so that long packets can be scheduled. In the next round, the queue with the negative weight value is not scheduled until its weight value becomes positive.
WDRR offsets the disadvantages of PQ scheduling and WRR scheduling. In PQ scheduling, packets in queues with lower priorities cannot be scheduled for a long time if congestion occurs. In WRR scheduling, bandwidth is allocated improperly when the packet length of each queue is different or variable.
When WDRR scheduling is used, set the weight for each queue. The switch schedules queues in turn according to the weights.
Precautions
When WDRR scheduling is applied and the weight of a queue is set to 0, the queue uses PQ scheduling and the scheduling mode is PQ+WDRR.
For the S2720-EI, S5720I-SI, S5720-LI, S5720S-LI, S5720S-SI, S5720-SI, S5730S-EI, S5730-SI, S6720-LI, S6720S-LI, S6720S-SI, and S6720-SI:
When configuring the PQ+WDRR scheduling mode, ensure that queues with weight 0 (queues using PQ scheduling) are consecutively configured, without being interrupted by the configuration of the queues using WDRR scheduling.
If PQ+WDRR scheduling is used and the numbers of the queues using PQ scheduling are consecutive (for example, queue 0, queues 0 and 1, and queues 0 to 2), the device schedules packets in queues using PQ scheduling after scheduling for the packets in queues using WDRR scheduling is completed.
On the S5720-EI, if the queue scheduling mode is changed or the weight is changed during queue scheduling, packet loss occurs within 250 ms.
On the S6720-EI and S6720S-EI, if the queue scheduling mode is changed or the weight is changed during queue scheduling, packet loss occurs within 20 ms.
To set the same WDRR weight on multiple interfaces, perform the configuration on a port group to reduce the workload.
Example
<HUAWEI> system-view [HUAWEI] interface gigabitethernet 0/0/1 [HUAWEI-GigabitEthernet0/0/1] qos drr [HUAWEI-GigabitEthernet0/0/1] qos queue 4 drr weight 9
<HUAWEI> system-view [HUAWEI] qos schedule-profile test [HUAWEI-qos-schedule-profile-test] qos drr [HUAWEI-qos-schedule-profile-test] qos queue 4 drr weight 9 [HUAWEI-qos-schedule-profile-test] quit [HUAWEI] interface gigabitethernet 0/0/1 [HUAWEI-GigabitEthernet0/0/1] qos schedule-profile test