Function NewFailoverClusterClient

sentinel.go:1199–1269

------------------------------------------------------------------------------ NewFailoverClusterClient returns a client that supports routing read-only commands to a replica node. Passing nil FailoverOptions will cause a panic.

(failoverOpt *FailoverOptions)

// to a replica node.
// Passing nil FailoverOptions will cause a panic.
func NewFailoverClusterClient(failoverOpt *FailoverOptions) *ClusterClient {
	if failoverOpt == nil {
		panic("redis: NewFailoverClusterClient nil options")
	}

	sentinelAddrs := make([]string, len(failoverOpt.SentinelAddrs))
	copy(sentinelAddrs, failoverOpt.SentinelAddrs)

	failover := &sentinelFailover{
		opt:           failoverOpt,
		sentinelAddrs: sentinelAddrs,
	}

	opt := failoverOpt.clusterOptions()
	if failoverOpt.DB != 0 {
		onConnect := opt.OnConnect

		opt.OnConnect = func(ctx context.Context, cn *Conn) error {
			if err := cn.Select(ctx, failoverOpt.DB).Err(); err != nil {
				return err
			}

			if onConnect != nil {
				return onConnect(ctx, cn)
			}

			return nil
		}
	}

	opt.ClusterSlots = func(ctx context.Context) ([]ClusterSlot, error) {
		masterAddr, err := failover.MasterAddr(ctx)
		if err != nil {
			return nil, err
		}

		nodes := []ClusterNode{{
			Addr: masterAddr,
		}}

		replicaAddrs, err := failover.replicaAddrs(ctx, false)
		if err != nil {
			return nil, err
		}

		for _, replicaAddr := range replicaAddrs {
			nodes = append(nodes, ClusterNode{
				Addr: replicaAddr,
			})
		}

		slots := []ClusterSlot{
			{
				Start: 0,
				End:   16383,
				Nodes: nodes,
			},
		}