servicediscovery

Documentation

Index

• Constants
• Variables
• func NewMockServiceDiscovery(urls []string, tlsCfg *tls.Config) *mockServiceDiscovery
• type APIKind
• type LeaderSwitchedCallbackFunc
• type ServiceClient
• type ServiceDiscovery
  • func NewDefaultServiceDiscovery(ctx context.Context, cancel context.CancelFunc, urls []string, ...) ServiceDiscovery
  • func NewServiceDiscovery(ctx context.Context, cancel context.CancelFunc, wg *sync.WaitGroup, ...) ServiceDiscovery
  • func NewTSOServiceDiscovery(ctx context.Context, metacli metastorage.Client, ...) ServiceDiscovery
• type UpdateKeyspaceIDFunc

Constants

const (
	// MemberUpdateInterval is the interval to update the member list.
	MemberUpdateInterval = time.Minute
	// UpdateMemberMaxBackoffTime is the max time to back off when updating the member list.
	UpdateMemberMaxBackoffTime = 100 * time.Millisecond
	// UpdateMemberBackOffBaseTime is the base time to back off when updating the member list.
	// Here we use 20ms is because getting timestamp will print a warning log if the time exceeds 30ms.
	UpdateMemberBackOffBaseTime = 20 * time.Millisecond
	// UpdateMemberTimeout is the timeout to update the member list.
	// Use a shorter timeout to recover faster from network isolation.
	UpdateMemberTimeout = time.Second
)

Variables

var MemberHealthCheckInterval = time.Second

MemberHealthCheckInterval might be changed in the unit to shorten the testing time.

Functions

func NewMockServiceDiscovery

func NewMockServiceDiscovery(urls []string, tlsCfg *tls.Config) *mockServiceDiscovery

NewMockServiceDiscovery creates a mock service discovery.

Types

type APIKind

type APIKind int

APIKind defines how this API should be handled.

const (
	// ForwardAPIKind means this API should be forwarded from the followers to the leader.
	ForwardAPIKind APIKind = iota
	// UniversalAPIKind means this API can be handled by both the leader and the followers.
	UniversalAPIKind
)

type LeaderSwitchedCallbackFunc

type LeaderSwitchedCallbackFunc func(string) error

LeaderSwitchedCallbackFunc is the callback function for leader switched event

type ServiceClient

type ServiceClient interface {
	// GetURL returns the client url of the PD/etcd server.
	GetURL() string
	// GetClientConn returns the gRPC connection of the service client.
	// It returns nil if the connection is not available.
	GetClientConn() *grpc.ClientConn
	// BuildGRPCTargetContext builds a context object with a gRPC context.
	// ctx: the original context object.
	// mustLeader: whether must send to leader.
	BuildGRPCTargetContext(ctx context.Context, mustLeader bool) context.Context
	// IsConnectedToLeader returns whether the connected PD server is leader.
	IsConnectedToLeader() bool
	// Available returns if the network or other availability for the current service client is available.
	Available() bool
	// NeedRetry checks if client need to retry based on the PD server error response.
	// And It will mark the client as unavailable if the pd error shows the follower can't handle request.
	NeedRetry(*pdpb.Error, error) bool
}

ServiceClient is an interface that defines a set of operations for a raw PD gRPC client to specific PD server.

type ServiceDiscovery

type ServiceDiscovery interface {
	// Init initialize the concrete client underlying
	Init() error
	// Close releases all resources
	Close()
	// GetClusterID returns the ID of the cluster
	GetClusterID() uint64
	// GetKeyspaceID returns the ID of the keyspace
	GetKeyspaceID() uint32
	// SetKeyspaceID sets the ID of the keyspace
	SetKeyspaceID(id uint32)
	// GetKeyspaceGroupID returns the ID of the keyspace group
	GetKeyspaceGroupID() uint32
	// GetServiceURLs returns the URLs of the servers providing the service
	GetServiceURLs() []string
	// GetServingEndpointClientConn returns the grpc client connection of the serving endpoint
	// which is the leader in a quorum-based cluster or the primary in a primary/secondary
	// configured cluster.
	GetServingEndpointClientConn() *grpc.ClientConn
	// GetClientConns returns the mapping {URL -> a gRPC connection}
	GetClientConns() *sync.Map
	// GetServingURL returns the serving endpoint which is the leader in a quorum-based cluster
	// or the primary in a primary/secondary configured cluster.
	GetServingURL() string
	// GetBackupURLs gets the URLs of the current reachable backup service
	// endpoints. Backup service endpoints are followers in a quorum-based cluster or
	// secondaries in a primary/secondary configured cluster.
	GetBackupURLs() []string
	// GetServiceClient tries to get the leader/primary ServiceClient.
	// If the leader ServiceClient meets network problem,
	// it returns a follower/secondary ServiceClient which can forward the request to leader.
	GetServiceClient() ServiceClient
	// GetServiceClientByKind tries to get the ServiceClient with the given API kind.
	GetServiceClientByKind(kind APIKind) ServiceClient
	// GetAllServiceClients tries to get all ServiceClient.
	// If the leader is not nil, it will put the leader service client first in the slice.
	GetAllServiceClients() []ServiceClient
	// GetOrCreateGRPCConn returns the corresponding grpc client connection of the given url.
	GetOrCreateGRPCConn(url string) (*grpc.ClientConn, error)
	// ScheduleCheckMemberChanged is used to trigger a check to see if there is any membership change
	// among the leader/followers in a quorum-based cluster or among the primary/secondaries in a
	// primary/secondary configured cluster.
	ScheduleCheckMemberChanged()
	// CheckMemberChanged immediately check if there is any membership change among the leader/followers
	// in a quorum-based cluster or among the primary/secondaries in a primary/secondary configured cluster.
	CheckMemberChanged() error
	// ExecAndAddLeaderSwitchedCallback executes the callback once and adds it to the callback list then.
	ExecAndAddLeaderSwitchedCallback(cb LeaderSwitchedCallbackFunc)
	// AddLeaderSwitchedCallback adds callbacks which will be called when the leader
	// in a quorum-based cluster or the primary in a primary/secondary configured cluster
	// is switched.
	AddLeaderSwitchedCallback(cb LeaderSwitchedCallbackFunc)
	// AddMembersChangedCallback adds callbacks which will be called when any leader/follower
	// in a quorum-based cluster or any primary/secondary in a primary/secondary configured cluster
	// is changed.
	AddMembersChangedCallback(cb func())
}

ServiceDiscovery defines the general interface for service discovery on a quorum-based cluster or a primary/secondary configured cluster.

func NewDefaultServiceDiscovery

func NewDefaultServiceDiscovery(
	ctx context.Context, cancel context.CancelFunc,
	urls []string, tlsCfg *tls.Config,
) ServiceDiscovery

NewDefaultServiceDiscovery returns a new default service discovery-based client.

func NewServiceDiscovery

func NewServiceDiscovery(
	ctx context.Context, cancel context.CancelFunc,
	wg *sync.WaitGroup,
	serviceModeUpdateCb func(pdpb.ServiceMode),
	updateKeyspaceIDFunc UpdateKeyspaceIDFunc,
	keyspaceID uint32,
	urls []string, tlsCfg *tls.Config, option *opt.Option,
) ServiceDiscovery

NewServiceDiscovery returns a new service discovery-based client.

func NewTSOServiceDiscovery

func NewTSOServiceDiscovery(
	ctx context.Context, metacli metastorage.Client, serviceDiscovery ServiceDiscovery,
	keyspaceID uint32, tlsCfg *tls.Config, option *opt.Option,
) ServiceDiscovery

NewTSOServiceDiscovery returns a new client-side service discovery for the independent TSO service.

type UpdateKeyspaceIDFunc

type UpdateKeyspaceIDFunc func() error

UpdateKeyspaceIDFunc is the function type for updating the keyspace ID.