temporal server grpc 接口实现
AdminHandler      gRPC handler interface for adminservice
WorkflowHandler   gRPC handler interface for workflowservice
Handler           gRPC handler interface for historyservice
Handler           gRPC handler interface for matchingservice

temporal/service/frontend/adminHandler.go
temporal/service/frontend/workflowHandler.go
temporal/service/history/handler.go
temporal/service/matching/handler.go

DLQMessageHandler is the interface handles namespace DLQ messages
DLQ messages ?  
DLQ(Dead Letter Queue) ?

temporal/common/persistence/dataInterfaces.go
  // ClusterMetadataManager is used to manage cluster-wide metadata and configuration
  ClusterMetadataManager interface {
    Closeable
    GetName() string
    GetClusterMembers(request *GetClusterMembersRequest) (*GetClusterMembersResponse, error)
    UpsertClusterMembership(request *UpsertClusterMembershipRequest) error
    PruneClusterMembership(request *PruneClusterMembershipRequest) error
    ListClusterMetadata(request *ListClusterMetadataRequest) (*ListClusterMetadataResponse, error)
    GetCurrentClusterMetadata() (*GetClusterMetadataResponse, error)
    GetClusterMetadata(request *GetClusterMetadataRequest) (*GetClusterMetadataResponse, error)
    SaveClusterMetadata(request *SaveClusterMetadataRequest) (bool, error)
    DeleteClusterMetadata(request *DeleteClusterMetadataRequest) error
  }

temporal/common/util.go
// WorkflowIDToHistoryShard is used to map namespaceID-workflowID pair to a shardID
func WorkflowIDToHistoryShard(
	namespaceID string,
	workflowID string,
	numberOfShards int32,
) int32 {
	idBytes := []byte(namespaceID + "_" + workflowID)
	hash := farm.Fingerprint32(idBytes)
	return int32(hash%uint32(numberOfShards)) + 1 // ShardID starts with 1
}