gateway

package
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Published: Jun 22, 2016 License: BSD-3-Clause Imports: 21 Imported by: 0

Documentation

Overview

Package gateway contains the routing layer of vtgate. A Gateway can take a query targeted to a keyspace/shard/tablet_type and send it off.

Index

Constants

This section is empty.

Variables

This section is empty.

Functions

func NewShardError

func NewShardError(in error, keyspace, shard string, tabletType topodatapb.TabletType, tablet *topodatapb.Tablet, inTransaction bool) error

NewShardError returns a ShardError which preserves the original error code if possible, adds the connection context and adds a bit to determine whether the keyspace/shard needs to be re-resolved for a potential sharding event (namely, if we were in a transaction).

func RegisterCreator

func RegisterCreator(name string, gc Creator)

RegisterCreator registers a Creator with given name.

Types

type Creator

type Creator func(hc discovery.HealthCheck, topoServer topo.Server, serv topo.SrvTopoServer, cell string, retryCount int, tabletTypesToWait []topodatapb.TabletType) Gateway

Creator is the factory method which can create the actual gateway object.

func GetCreator

func GetCreator() Creator

GetCreator returns the Creator specified by the gateway_implementation flag.

type Gateway

type Gateway interface {
	// Execute executes the non-streaming query for the specified keyspace, shard, and tablet type.
	Execute(ctx context.Context, keyspace, shard string, tabletType topodatapb.TabletType, query string, bindVars map[string]interface{}, transactionID int64) (*sqltypes.Result, error)

	// ExecuteBatch executes a group of queries for the specified keyspace, shard, and tablet type.
	ExecuteBatch(ctx context.Context, keyspace, shard string, tabletType topodatapb.TabletType, queries []querytypes.BoundQuery, asTransaction bool, transactionID int64) ([]sqltypes.Result, error)

	// StreamExecute executes a streaming query for the specified keyspace, shard, and tablet type.
	StreamExecute(ctx context.Context, keyspace, shard string, tabletType topodatapb.TabletType, query string, bindVars map[string]interface{}) (sqltypes.ResultStream, error)

	// Begin starts a transaction for the specified keyspace, shard, and tablet type.
	// It returns the transaction ID.
	Begin(ctx context.Context, keyspace string, shard string, tabletType topodatapb.TabletType) (int64, error)

	// Commit commits the current transaction for the specified keyspace, shard, and tablet type.
	Commit(ctx context.Context, keyspace, shard string, tabletType topodatapb.TabletType, transactionID int64) error

	// Rollback rolls back the current transaction for the specified keyspace, shard, and tablet type.
	Rollback(ctx context.Context, keyspace, shard string, tabletType topodatapb.TabletType, transactionID int64) error

	// BeginExecute executes a begin and the non-streaming query
	// for the specified keyspace, shard, and tablet type.
	BeginExecute(ctx context.Context, keyspace, shard string, tabletType topodatapb.TabletType, query string, bindVars map[string]interface{}) (*sqltypes.Result, int64, error)

	// BeginExecuteBatch executes a begin and a group of queries
	// for the specified keyspace, shard, and tablet type.
	BeginExecuteBatch(ctx context.Context, keyspace, shard string, tabletType topodatapb.TabletType, queries []querytypes.BoundQuery, asTransaction bool) ([]sqltypes.Result, int64, error)

	// SplitQuery splits a query into sub-queries for the specified keyspace, shard, and tablet type.
	SplitQuery(ctx context.Context, keyspace, shard string, tabletType topodatapb.TabletType, sql string, bindVariables map[string]interface{}, splitColumn string, splitCount int64) ([]querytypes.QuerySplit, error)

	// SplitQuery splits a query into sub-queries for the specified keyspace, shard, and tablet type.
	// TODO(erez): Rename to SplitQuery after migration to SplitQuery V2.
	SplitQueryV2(
		ctx context.Context,
		keyspace,
		shard string,
		tabletType topodatapb.TabletType,
		sql string,
		bindVariables map[string]interface{},
		splitColumns []string,
		splitCount int64,
		numRowsPerQueryPart int64,
		algorithm querypb.SplitQueryRequest_Algorithm) ([]querytypes.QuerySplit, error)

	// Close shuts down underlying connections.
	Close(ctx context.Context) error

	// CacheStatus returns a list of TabletCacheStatus per tablet.
	CacheStatus() TabletCacheStatusList
}

A Gateway is the query processing module for each shard, which is used by ScatterConn.

type ShardError

type ShardError struct {
	// ShardIdentifier is the keyspace+shard.
	ShardIdentifier string
	// InTransaction indicates if it is inside a transaction.
	InTransaction bool
	// Err preserves the original error, so that we don't need to parse the error string.
	Err error
	// ErrorCode is the error code to use for all the tablet errors in aggregate
	ErrorCode vtrpcpb.ErrorCode
}

ShardError is the error about a specific shard. It implements vterrors.VtError.

func (*ShardError) Error

func (e *ShardError) Error() string

Error returns the error string.

func (*ShardError) VtErrorCode

func (e *ShardError) VtErrorCode() vtrpcpb.ErrorCode

VtErrorCode returns the underlying Vitess error code. This is part of vterrors.VtError interface.

type TabletCacheStatus

type TabletCacheStatus struct {
	Keyspace   string
	Shard      string
	TabletType topodatapb.TabletType
	Name       string
	Addr       string

	QueryCount uint64
	QueryError uint64
	QPS        uint64
	AvgLatency float64 // in milliseconds
}

TabletCacheStatus contains the status per tablet for a gateway.

type TabletCacheStatusList

type TabletCacheStatusList []*TabletCacheStatus

TabletCacheStatusList is a slice of TabletCacheStatus.

func (TabletCacheStatusList) Len

func (gtcsl TabletCacheStatusList) Len() int

Len is part of sort.Interface.

func (TabletCacheStatusList) Less

func (gtcsl TabletCacheStatusList) Less(i, j int) bool

Less is part of sort.Interface.

func (TabletCacheStatusList) Swap

func (gtcsl TabletCacheStatusList) Swap(i, j int)

Swap is part of sort.Interface.

type TabletStatusAggregator

type TabletStatusAggregator struct {
	Keyspace   string
	Shard      string
	TabletType topodatapb.TabletType
	Name       string // the alternative name of a tablet
	Addr       string // the host:port of a tablet

	QueryCount uint64
	QueryError uint64
	// contains filtered or unexported fields
}

TabletStatusAggregator tracks tablet status for a gateway.

func NewTabletStatusAggregator

func NewTabletStatusAggregator(keyspace, shard string, tabletType topodatapb.TabletType, name string) *TabletStatusAggregator

NewTabletStatusAggregator creates a TabletStatusAggregator.

func (*TabletStatusAggregator) GetCacheStatus

func (tsa *TabletStatusAggregator) GetCacheStatus() *TabletCacheStatus

GetCacheStatus returns a TabletCacheStatus representing the current gateway status.

func (*TabletStatusAggregator) UpdateQueryInfo

func (tsa *TabletStatusAggregator) UpdateQueryInfo(addr string, tabletType topodatapb.TabletType, elapsed time.Duration, hasError bool)

UpdateQueryInfo updates the aggregator with the given information about a query.

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