queryCoord的balancer分析

queryCoord的balancer分析

milvus版本:v2.3.2

涉及到一个参数设置：

queryCoord.balancer = ScoreBasedBalancer

milvus内置的balancer有3种：

代码位置:internal\querycoordv2\balance\balance.go

var (
    RoundRobinBalancerName    = "RoundRobinBalancer"
    RowCountBasedBalancerName = "RowCountBasedBalancer"
    ScoreBasedBalancerName    = "ScoreBasedBalancer"
)

Balance接口:

type Balance interface {
   
    AssignSegment(collectionID int64, segments []*meta.Segment, nodes []int64) []SegmentAssignPlan
    AssignChannel(channels []*meta.DmChannel, nodes []int64) []ChannelAssignPlan
    BalanceReplica(replica *meta.Replica) ([]SegmentAssignPlan, []ChannelAssignPlan)
}

这个接口有3个实现。

ScoreBasedBalancer、RoundRobinBalancer、RowCountBasedBalancer。

func (controller *CheckerController) check(ctx context.Context, checkerType string) {
   
    checker := controller.checkers[checkerType]
    tasks := checker.Check(ctx)

    for _, task := range tasks {
   
        err := controller.scheduler.Add(task)
        if err != nil {
   
            task.Cancel(err)
            continue
        }
    }
}

checker.Check()有4个实现，会调用AssignSegment、AssignChannel、BalanceReplica方法。