load-balance dynamic-adjust enable

Function

The load-balance dynamic-adjust enable command enables the dynamic load balancing adjustment function.

The undo load-balance dynamic-adjust enable command disables the dynamic load balancing adjustment function.

By default, the dynamic load balancing adjustment function is disabled on an interface board.

Format

load-balance dynamic-adjust enable

undo load-balance dynamic-adjust enable

Parameters

None

Views

Slot view

Default Level

3: Management level

Task Name and Operations

Task Name	Operations
forwarding	write

Usage Guidelines

Usage Scenario

The device supports multiple load balancing configurations, including IP packet, VPLS, VLL load balancing configurations. If these configurations cannot prevent uneven load balancing, run the load-balance dynamic-adjust enable command to enable the dynamic load balancing adjustment function on a specific board. This function enables the Router to dynamically adjust load balancing on a board, improving the hash precision.

Precautions

In VS mode, this command is supported only by the admin VS.

The dynamic load balancing adjustment function configured using the load-balance dynamic-adjust enable command does not take effect for tunnel interfaces with service classes configured.

Dynamic load balancing adjustment enables a device to re-select path based on the hash algorithm. As a result, this causes a temporary packet mis-sequence, and the packet mis-sequence problem is rectified after dynamic load balancing adjustment is complete.

Applicable scenarios:
Multiple flows are hashed to one or two outbound interfaces, with other outbound interfaces unattended.
After dynamic load balancing adjustment is enabled, the default traffic offset threshold implemented by the system is 30%. After the adjustment is successful, the offset threshold is less than 30% and cannot be determined. In addition, an offset threshold cannot be configured using a command. If the traffic offset threshold is set to a value lower than 30%, for example, 1%, the dynamic adjustment result cannot be ensured.
Inapplicable scenarios:
No outbound interface has traffic.
The number of flows to be load-balanced is lower than four times the number of load balancing outbound interfaces. For example, ten flows are load-balanced to three outbound interfaces.
A burst of traffic is sent to one outbound interface at a rate higher than the average traffic rate multiplying a factor of 1+traffic offset threshold. The average traffic rate is calculated based on a 1-minute traffic statistics, slightly deviating from the actual value. Therefore, reducing the traffic offset threshold by 2% or 3% in calculation is recommended.

Example

# Enable the dynamic load balancing adjustment function.

<HUAWEI> system-view
[~HUAWEI] slot 1
[*HUAWEI-slot-1] load-balance dynamic-adjust enable