Documentation
¶
Overview ¶
Package wrr provides weighted round-robin load balancing selector. The selector picks instances based on their weight values in metadata. Supported weight values in metadata["weight"]: 100, 80, 50, 20, 10, default 1. When the instance count exceeds wrrP2CFallbackThreshold (100), it automatically falls back to P2C to avoid O(n) per-selection overhead becoming a CPU hotspot.
加权轮询负载均衡选择器包，提供基于权重的轮询选择算法。 选择器根据实例 metadata 中的权重值进行选择。 支持的 metadata["weight"] 权重值：100, 80, 50, 20, 10，默认为 1。 当实例数量超过 wrrP2CFallbackThreshold (100) 时，自动降级到 P2C， 避免 O(n) 的每次选择开销成为 CPU 热点。
Eg:
// 注册 Provider app.Register(wrr.NewProvider()) // 使用选择器 selector := c.MustMake(discoverycontract.SelectorKey).(discoverycontract.Selector) instance, doneFunc, _ := selector.Select(ctx, instances)
Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Provider ¶
type Provider struct{}
Provider registers the WRR selector contract.
Provider 注册加权轮询选择器契约。
func NewProvider ¶
func NewProvider() *Provider
NewProvider creates a new WRR selector provider instance.
NewProvider 创建新的加权轮询选择器 Provider 实例。
func (*Provider) Boot ¶
func (p *Provider) Boot(c runtimecontract.Container) error
Boot is a no-op for WRR selector provider.
Boot 加权轮询选择器 Provider 无启动逻辑。
func (*Provider) DependsOn ¶
DependsOn returns the keys this provider depends on. WRR selector has no dependencies.
DependsOn 返回该 provider 依赖的 key。 WRR selector 无依赖。
func (*Provider) IsDefer ¶
IsDefer returns true, selector can be deferred until first use.
IsDefer 返回 true，选择器可延迟初始化直到首次使用。
func (*Provider) Name ¶
Name returns the provider name "selector.wrr".
Name 返回 Provider 名称 "selector.wrr"。
type WRRSelector ¶
type WRRSelector struct {
// contains filtered or unexported fields
}
WRRSelector implements discoverycontract.Selector with weighted round-robin algorithm. When the instance count exceeds wrrP2CFallbackThreshold, it falls back to P2C to avoid the O(n) per-selection overhead becoming a CPU hotspot.
WRRSelector 使用加权轮询算法实现 discoverycontract.Selector 接口。 当实例数量超过 wrrP2CFallbackThreshold 时，自动降级到 P2C， 避免 O(n) 的每次选择开销成为 CPU 热点。
func NewWRRSelector ¶
func NewWRRSelector() *WRRSelector
NewWRRSelector creates a new WRR selector instance.
NewWRRSelector 创建新的加权轮询选择器实例。
func (*WRRSelector) Select ¶
func (s *WRRSelector) Select(ctx context.Context, instances []transportcontract.ServiceInstance, opts ...discoverycontract.SelectOption) ( selected transportcontract.ServiceInstance, done discoverycontract.DoneFunc, err error, )
Select picks an instance using weighted round-robin algorithm. Core logic: Calculate weights, add to current, pick max, subtract total. Falls back to P2C when instance count exceeds wrrP2CFallbackThreshold.
Select 使用加权轮询算法选择实例。 核心逻辑：计算权重、累加到当前权重、选择最大值、减去总权重。 实例数量超过 wrrP2CFallbackThreshold 时自动降级到 P2C。
Source Files