vstreamer

Documentation

Index

• Constants
• Variables
• func AdjustPacketSize(size int) func()
• func GetBinlogRotationThreshold() int64
• func SetBinlogRotationThreshold(threshold int64)
• type ColExpr
• type Engine
  • func NewEngine(env tabletenv.Env, ts srvtopo.Server, se *schema.Engine, ...) *Engine
  • func (vse *Engine) Close()
  • func (vse *Engine) InitDBConfig(keyspace, shard string)
  • func (vse *Engine) IsOpen() bool
  • func (vse *Engine) Open()
  • func (vse *Engine) ServeHTTP(response http.ResponseWriter, request *http.Request)
  • func (vse *Engine) Stream(ctx context.Context, startPos string, tablePKs []*binlogdatapb.TableLastPK, ...) error
  • func (vse *Engine) StreamResults(ctx context.Context, query string, ...) error
  • func (vse *Engine) StreamRows(ctx context.Context, query string, lastpk []sqltypes.Value, ...) error
• type Filter
• type Opcode
• type PacketSizer
  • func DefaultPacketSizer() PacketSizer
• type Plan
• type RowStreamer
  • func NewRowStreamer(ctx context.Context, cp dbconfigs.Connector, se *schema.Engine, query string, ...) RowStreamer
• type Table
  • func (ta *Table) FindColumn(name sqlparser.IdentifierCI) int

Constants

const (
	// Equal is used to filter a comparable column on a specific value
	Equal = Opcode(iota)
	// VindexMatch is used for an in_keyrange() construct
	VindexMatch
	// LessThan is used to filter a comparable column if < specific value
	LessThan
	// LessThanEqual is used to filter a comparable column if <= specific value
	LessThanEqual
	// GreaterThan is used to filter a comparable column if > specific value
	GreaterThan
	// GreaterThanEqual is used to filter a comparable column if >= specific value
	GreaterThanEqual
	// NotEqual is used to filter a comparable column if != specific value
	NotEqual
)

Variables

var HeartbeatTime = 900 * time.Millisecond

HeartbeatTime is set to slightly below 1s, compared to idleTimeout set by VPlayer at slightly above 1s. This minimizes conflicts between the two timeouts.

Functions

func AdjustPacketSize

func AdjustPacketSize(size int) func()

AdjustPacketSize temporarily adjusts the default packet sizes to the given value. Calling the returned cleanup function resets them to their original value. This function is only used for testing.

func GetBinlogRotationThreshold

func GetBinlogRotationThreshold() int64

GetBinlogRotationThreshold returns the current byte size at which a VStreamer will attempt to rotate the binary log before starting a GTID snapshot based stream (e.g. a ResultStreamer or RowStreamer).

func SetBinlogRotationThreshold

func SetBinlogRotationThreshold(threshold int64)

SetBinlogRotationThreshold sets the byte size at which a VStreamer will attempt to rotate the binary log before starting a GTID snapshot based stream (e.g. a ResultStreamer or RowStreamer).

Types

type ColExpr

type ColExpr struct {
	// ColNum specifies the source column value.
	ColNum int

	// Vindex and VindexColumns, if set, will be used to generate
	// a keyspace_id. If so, ColNum is ignored.
	// VindexColumns contains the column numbers of the table,
	// and not the column numbers of the stream to be sent.
	Vindex        vindexes.Vindex
	VindexColumns []int

	Field *querypb.Field

	FixedValue sqltypes.Value
}

ColExpr represents a column expression.

type Engine

type Engine struct {
	// contains filtered or unexported fields
}

Engine is the engine for handling vreplication streaming requests.

func NewEngine

func NewEngine(env tabletenv.Env, ts srvtopo.Server, se *schema.Engine, lagThrottler *throttle.Throttler, cell string) *Engine

NewEngine creates a new Engine. Initialization sequence is: NewEngine->InitDBConfig->Open. Open and Close can be called multiple times and are idempotent.

func (*Engine) Close

func (vse *Engine) Close()

Close closes the Engine service.

func (*Engine) InitDBConfig

func (vse *Engine) InitDBConfig(keyspace, shard string)

InitDBConfig initializes the target parameters for the Engine.

func (*Engine) IsOpen

func (vse *Engine) IsOpen() bool

IsOpen checks if the engine is opened

func (*Engine) Open

func (vse *Engine) Open()

Open starts the Engine service.

func (*Engine) ServeHTTP

func (vse *Engine) ServeHTTP(response http.ResponseWriter, request *http.Request)

ServeHTTP shows the current VSchema.

func (*Engine) Stream

func (vse *Engine) Stream(ctx context.Context, startPos string, tablePKs []*binlogdatapb.TableLastPK, filter *binlogdatapb.Filter, send func([]*binlogdatapb.VEvent) error) error

Stream starts a new stream. This streams events from the binary logs

func (*Engine) StreamResults

func (vse *Engine) StreamResults(ctx context.Context, query string, send func(*binlogdatapb.VStreamResultsResponse) error) error

StreamResults streams results of the query with the gtid.

func (*Engine) StreamRows

func (vse *Engine) StreamRows(ctx context.Context, query string, lastpk []sqltypes.Value, send func(*binlogdatapb.VStreamRowsResponse) error) error

StreamRows streams rows. This streams the table data rows (so we can copy the table data snapshot)

type Filter

type Filter struct {
	Opcode Opcode
	ColNum int
	Value  sqltypes.Value

	// Parameters for VindexMatch.
	// Vindex, VindexColumns and KeyRange, if set, will be used
	// to filter the row.
	// VindexColumns contains the column numbers of the table,
	// and not the column numbers of the stream to be sent.
	Vindex        vindexes.Vindex
	VindexColumns []int
	KeyRange      *topodatapb.KeyRange
}

Filter contains opcodes for filtering.

type Opcode

type Opcode int

Opcode enumerates the operators supported in a where clause

type PacketSizer

type PacketSizer interface {
	ShouldSend(byteCount int) bool
	Record(byteCount int, duration time.Duration)
	Limit() int
}

PacketSizer is a controller that adjusts the size of the packets being sent by the vstreamer at runtime

func DefaultPacketSizer

func DefaultPacketSizer() PacketSizer

DefaultPacketSizer creates a new PacketSizer using the default settings. If dynamic packet sizing is enabled, this will return a dynamicPacketSizer.

type Plan

type Plan struct {
	Table *Table

	// ColExprs is the list of column expressions to be sent
	// in the stream.
	ColExprs []ColExpr

	// Filters is the list of filters to be applied to the columns
	// of the table.
	Filters []Filter
	// contains filtered or unexported fields
}

Plan represents the plan for a table.

type RowStreamer

type RowStreamer interface {
	Stream() error
	Cancel()
}

RowStreamer exposes an externally usable interface to rowStreamer.

func NewRowStreamer

func NewRowStreamer(ctx context.Context, cp dbconfigs.Connector, se *schema.Engine, query string, lastpk []sqltypes.Value, send func(*binlogdatapb.VStreamRowsResponse) error, vse *Engine) RowStreamer

NewRowStreamer returns a RowStreamer

type Table

type Table struct {
	Name   string
	Fields []*querypb.Field
}

Table contains the metadata for a table.

func (*Table) FindColumn

func (ta *Table) FindColumn(name sqlparser.IdentifierCI) int

FindColumn finds a column in the table. It returns the index if found. Otherwise, it returns -1.