policy

type BackendCtx interface {
	ID() string
	Addr() string
	// ConnCount indicates the count of current connections.
	ConnCount() int
	// ConnScore = current connections + incoming connections - outgoing connections.
	ConnScore() int
	Healthy() bool
	Local() bool
	Keyspace() string
	GetBackendInfo() observer.BackendInfo
}

type BalancePolicy interface {
	Init(cfg *config.Config)
	BackendToRoute(backends []BackendCtx) BackendCtx
	// RouteableBackends returns the backends that are eligible for routing under the current policy.
	RouteableBackends(backends []BackendCtx) []BackendCtx
	// balanceCount is the count of connections to balance per second.
	BackendsToBalance(backends []BackendCtx) (from, to BackendCtx, balanceCount float64, reason string, logFields []zap.Field)
	SetConfig(cfg *config.Config)
}

type SimpleBalancePolicy struct {
}