tabletconn

Documentation

Index

• Constants
• Variables
• func RegisterDialer(name string, dialer TabletDialer)
• type ErrFunc
• type OperationalError
  • func (e OperationalError) Error() string
• type ServerError
  • func (e *ServerError) Error() string
• type TabletConn
• type TabletDialer
  • func GetDialer() TabletDialer

Constants

const (
	// Refer to tabletserver/tablet_error.go for a more detailed explanation on
	// what these errors mean from the VtTablet perspective.
	ERR_NORMAL = iota
	ERR_RETRY
	ERR_FATAL
	ERR_TX_POOL_FULL
	ERR_NOT_IN_TX
)

const (
	ConnClosed = OperationalError("vttablet: Connection Closed")
	Cancelled  = OperationalError("vttablet: Context Cancelled")
)

Variables

var (
	// TabletProtocol is exported for unit tests
	TabletProtocol = flag.String("tablet_protocol", "grpc", "how to talk to the vttablets")
)

Functions

func RegisterDialer

func RegisterDialer(name string, dialer TabletDialer)

RegisterDialer is meant to be used by TabletDialer implementations to self register.

Types

type ErrFunc

type ErrFunc func() error

type OperationalError

type OperationalError string

OperationalError represents an error due to a failure to communicate with vttablet.

func (OperationalError) Error

func (e OperationalError) Error() string

type ServerError

type ServerError struct {
	Code int
	Err  string
}

ServerError represents an error that was returned from a vttablet server.

func (*ServerError) Error

func (e *ServerError) Error() string

type TabletConn

type TabletConn interface {
	// Execute executes a non-streaming query on vttablet.
	Execute(ctx context.Context, query string, bindVars map[string]interface{}, transactionId int64) (*mproto.QueryResult, error)

	// ExecuteBatch executes a group of queries.
	ExecuteBatch(ctx context.Context, queries []tproto.BoundQuery, asTransaction bool, transactionId int64) (*tproto.QueryResultList, error)

	// StreamExecute executes a streaming query on vttablet. It returns a channel, ErrFunc and error.
	// If error is non-nil, it means that the StreamExecute failed to send the request. Otherwise,
	// you can pull values from the channel till it's closed. Following this, you can call ErrFunc
	// to see if the stream ended normally or due to a failure.
	StreamExecute(ctx context.Context, query string, bindVars map[string]interface{}, transactionId int64) (<-chan *mproto.QueryResult, ErrFunc, error)

	// Transaction support
	Begin(ctx context.Context) (transactionId int64, err error)
	Commit(ctx context.Context, transactionId int64) error
	Rollback(ctx context.Context, transactionId int64) error

	// These should not be used for anything except tests for now; they will eventually
	// replace the existing methods.
	Execute2(ctx context.Context, query string, bindVars map[string]interface{}, transactionId int64) (*mproto.QueryResult, error)
	ExecuteBatch2(ctx context.Context, queries []tproto.BoundQuery, asTransaction bool, transactionId int64) (*tproto.QueryResultList, error)
	Begin2(ctx context.Context) (transactionId int64, err error)
	Commit2(ctx context.Context, transactionId int64) error
	Rollback2(ctx context.Context, transactionId int64) error
	StreamExecute2(ctx context.Context, query string, bindVars map[string]interface{}, transactionId int64) (<-chan *mproto.QueryResult, ErrFunc, error)

	// Close must be called for releasing resources.
	Close()

	// SetTarget can be called to change the target used for
	// subsequent calls. Can only be called if tabletType was not
	// set to UNKNOWN in TabletDialer.
	SetTarget(keyspace, shard string, tabletType pbt.TabletType) error

	// GetEndPoint returns the end point info.
	EndPoint() *pbt.EndPoint

	// SplitQuery splits a query into equally sized smaller queries by
	// appending primary key range clauses to the original query
	SplitQuery(ctx context.Context, query tproto.BoundQuery, splitColumn string, splitCount int) ([]tproto.QuerySplit, error)

	// StreamHealth streams StreamHealthResponse to the client
	StreamHealth(ctx context.Context) (<-chan *pb.StreamHealthResponse, ErrFunc, error)
}

TabletConn defines the interface for a vttablet client. It should not be concurrently used across goroutines.

type TabletDialer

type TabletDialer func(ctx context.Context, endPoint *pbt.EndPoint, keyspace, shard string, tabletType pbt.TabletType, timeout time.Duration) (TabletConn, error)

TabletDialer represents a function that will return a TabletConn object that can communicate with a tablet.

We support two modes of operation: 1 - using GetSessionId (right after dialing) to get a sessionId. 2 - using Target with each call (and never calling GetSessionId). If tabletType is set to UNKNOWN, we'll use mode 1. Mode 1 is being deprecated.

func GetDialer

func GetDialer() TabletDialer

GetDialer returns the dialer to use, described by the command line flag