ddl

Documentation

Index

• Constants
• Variables
• type BaseCallback
  • func (c *BaseCallback) OnChanged(err error) error
  • func (c *BaseCallback) OnJobRunBefore(job *model.Job)
  • func (c *BaseCallback) OnJobUpdated(job *model.Job)
  • func (c *BaseCallback) OnWatched(ctx goctx.Context)
• type Callback
• type DDL
  • func NewDDL(ctx goctx.Context, etcdCli *clientv3.Client, store kv.Storage, ...) DDL
• type Event
  • func (e *Event) String() string
• type SchemaSyncer
  • func NewMockSchemaSyncer() SchemaSyncer
  • func NewSchemaSyncer(etcdCli *clientv3.Client, id string) SchemaSyncer

Constants

const (
	// DDLAllSchemaVersions is the path on etcd that is used to store all servers current schema versions.
	// It's exported for testing.
	DDLAllSchemaVersions = "/tidb/ddl/all_schema_versions"
	// DDLGlobalSchemaVersion is the path on etcd that is used to store the latest schema versions.
	// It's exported for testing.
	DDLGlobalSchemaVersion = "/tidb/ddl/global_schema_version"
	// InitialVersion is the initial schema version for every server.
	// It's exported for testing.
	InitialVersion = "0"
)

const (

	// DDLOwnerKey is the ddl owner path that is saved to etcd, and it's exported for testing.
	DDLOwnerKey = "/tidb/ddl/fg/owner"
)

Variables

var (
	// TableColumnCountLimit is limit of the number of columns in a table.
	// It's exported for testing.
	TableColumnCountLimit = 512
	// EnableSplitTableRegion is a flag to decide whether to split a new region for
	// a newly created table. It takes effect only if the Storage supports split
	// region.
	EnableSplitTableRegion = false
)

var (

	// ErrInvalidDBState returns for invalid database state.
	ErrInvalidDBState = terror.ClassDDL.New(codeInvalidDBState, "invalid database state")
	// ErrInvalidTableState returns for invalid Table state.
	ErrInvalidTableState = terror.ClassDDL.New(codeInvalidTableState, "invalid table state")
	// ErrInvalidColumnState returns for invalid column state.
	ErrInvalidColumnState = terror.ClassDDL.New(codeInvalidColumnState, "invalid column state")
	// ErrInvalidIndexState returns for invalid index state.
	ErrInvalidIndexState = terror.ClassDDL.New(codeInvalidIndexState, "invalid index state")
	// ErrInvalidForeignKeyState returns for invalid foreign key state.
	ErrInvalidForeignKeyState = terror.ClassDDL.New(codeInvalidForeignKeyState, "invalid foreign key state")
	// ErrUnsupportedModifyPrimaryKey returns an error when add or drop the primary key.
	// It's exported for testing.
	ErrUnsupportedModifyPrimaryKey = terror.ClassDDL.New(codeUnsupportedModifyPrimaryKey, "unsupported %s primary key")

	// ErrColumnBadNull returns for a bad null value.
	ErrColumnBadNull = terror.ClassDDL.New(codeBadNull, "column cann't be null")
	// ErrCantRemoveAllFields returns for deleting all columns.
	ErrCantRemoveAllFields = terror.ClassDDL.New(codeCantRemoveAllFields, "can't delete all columns with ALTER TABLE")
	// ErrCantDropFieldOrKey returns for dropping a non-existent field or key.
	ErrCantDropFieldOrKey = terror.ClassDDL.New(codeCantDropFieldOrKey, "can't drop field; check that column/key exists")
	// ErrInvalidOnUpdate returns for invalid ON UPDATE clause.
	ErrInvalidOnUpdate = terror.ClassDDL.New(codeInvalidOnUpdate, "invalid ON UPDATE clause for the column")
	// ErrTooLongIdent returns for too long name of database/table/column.
	ErrTooLongIdent = terror.ClassDDL.New(codeTooLongIdent, "Identifier name too long")
	// ErrWrongDBName returns for wrong database name.
	ErrWrongDBName = terror.ClassDDL.New(codeWrongDBName, mysql.MySQLErrName[mysql.ErrWrongDBName])
	// ErrWrongTableName returns for wrong table name.
	ErrWrongTableName = terror.ClassDDL.New(codeWrongTableName, mysql.MySQLErrName[mysql.ErrWrongTableName])
	// ErrWrongColumnName returns for wrong column name.
	ErrWrongColumnName = terror.ClassDDL.New(codeWrongColumnName, mysql.MySQLErrName[mysql.ErrWrongColumnName])
	// ErrWrongNameForIndex returns for wrong index name.
	ErrWrongNameForIndex = terror.ClassDDL.New(codeWrongNameForIndex, mysql.MySQLErrName[mysql.ErrWrongNameForIndex])
)

var (
	// CheckVersFirstWaitTime is a waitting time before the owner checks all the servers of the schema version,
	// and it's an exported variable for testing.
	CheckVersFirstWaitTime = 50 * time.Millisecond
	// SyncerSessionTTL is the etcd session's TTL in seconds.
	// and it's an exported variable for testing.
	SyncerSessionTTL = 10 * 60
)

var RunWorker = true

RunWorker indicates if this TiDB server starts DDL worker and can run DDL job.

Types

type BaseCallback

type BaseCallback struct {
}

BaseCallback implements Callback.OnChanged interface.

func (*BaseCallback) OnChanged

func (c *BaseCallback) OnChanged(err error) error

OnChanged implements Callback interface.

func (*BaseCallback) OnJobRunBefore

func (c *BaseCallback) OnJobRunBefore(job *model.Job)

OnJobRunBefore implements Callback.OnJobRunBefore interface.

func (*BaseCallback) OnJobUpdated

func (c *BaseCallback) OnJobUpdated(job *model.Job)

OnJobUpdated implements Callback.OnJobUpdated interface.

func (*BaseCallback) OnWatched

func (c *BaseCallback) OnWatched(ctx goctx.Context)

OnWatched implements Callback.OnWatched interface.

type Callback

type Callback interface {
	// OnChanged is called after schema is changed.
	OnChanged(err error) error
	// OnJobRunBefore is called before running job.
	OnJobRunBefore(job *model.Job)
	// OnJobUpdated is called after the running job is updated.
	OnJobUpdated(job *model.Job)
	// OnWatched is called after watching owner is completed.
	OnWatched(ctx goctx.Context)
}

Callback is the interface supporting callback function when DDL changed.

type DDL

type DDL interface {
	CreateSchema(ctx context.Context, name model.CIStr, charsetInfo *ast.CharsetOpt) error
	DropSchema(ctx context.Context, schema model.CIStr) error
	CreateTable(ctx context.Context, ident ast.Ident, cols []*ast.ColumnDef,
		constrs []*ast.Constraint, options []*ast.TableOption) error
	CreateTableWithLike(ctx context.Context, ident, referIdent ast.Ident) error
	DropTable(ctx context.Context, tableIdent ast.Ident) (err error)
	CreateIndex(ctx context.Context, tableIdent ast.Ident, unique bool, indexName model.CIStr,
		columnNames []*ast.IndexColName, indexOption *ast.IndexOption) error
	DropIndex(ctx context.Context, tableIdent ast.Ident, indexName model.CIStr) error
	GetInformationSchema() infoschema.InfoSchema
	AlterTable(ctx context.Context, tableIdent ast.Ident, spec []*ast.AlterTableSpec) error
	TruncateTable(ctx context.Context, tableIdent ast.Ident) error
	RenameTable(ctx context.Context, oldTableIdent, newTableIdent ast.Ident) error
	// SetLease will reset the lease time for online DDL change,
	// it's a very dangerous function and you must guarantee that all servers have the same lease time.
	SetLease(ctx goctx.Context, lease time.Duration)
	// GetLease returns current schema lease time.
	GetLease() time.Duration
	// Stats returns the DDL statistics.
	Stats(vars *variable.SessionVars) (map[string]interface{}, error)
	// GetScope gets the status variables scope.
	GetScope(status string) variable.ScopeFlag
	// Stop stops DDL worker.
	Stop() error
	// RegisterEventCh registers event channel for ddl.
	RegisterEventCh(chan<- *Event)
	// SchemaSyncer gets the schema syncer.
	SchemaSyncer() SchemaSyncer
	// OwnerManager gets the owner manager, and it's used for testing.
	OwnerManager() owner.Manager
	// WorkerVars gets the session variables for DDL worker.
	WorkerVars() *variable.SessionVars
	// SetHook sets the hook. It's exported for testing.
	SetHook(h Callback)
}

DDL is responsible for updating schema in data store and maintaining in-memory InfoSchema cache.

func NewDDL

func NewDDL(ctx goctx.Context, etcdCli *clientv3.Client, store kv.Storage,
	infoHandle *infoschema.Handle, hook Callback, lease time.Duration, ctxPool *pools.ResourcePool) DDL

NewDDL creates a new DDL.

type Event

type Event struct {
	Tp         model.ActionType
	TableInfo  *model.TableInfo
	ColumnInfo *model.ColumnInfo
	IndexInfo  *model.IndexInfo
}

Event is an event that a ddl operation happened.

func (*Event) String

func (e *Event) String() string

String implements fmt.Stringer interface.

type SchemaSyncer

type SchemaSyncer interface {
	// Init sets the global schema version path to etcd if it isn't exist,
	// then watch this path, and initializes the self schema version to etcd.
	Init(ctx goctx.Context) error
	// UpdateSelfVersion updates the current version to the self path on etcd.
	UpdateSelfVersion(ctx goctx.Context, version int64) error
	// RemoveSelfVersionPath remove the self path from etcd.
	RemoveSelfVersionPath() error
	// OwnerUpdateGlobalVersion updates the latest version to the global path on etcd until updating is successful or the ctx is done.
	OwnerUpdateGlobalVersion(ctx goctx.Context, version int64) error
	// GlobalVersionCh gets the chan for watching global version.
	GlobalVersionCh() clientv3.WatchChan
	// MustGetGlobalVersion gets the global version. The only reason it fails is that ctx is done.
	MustGetGlobalVersion(ctx goctx.Context) (int64, error)
	// Done() returns a channel that closes when the syncer is no longer being refreshed.
	Done() <-chan struct{}
	// Restart restarts the syncer when it's on longer being refreshed.
	Restart(ctx goctx.Context) error
	// OwnerCheckAllVersions checks whether all followers' schema version are equal to
	// the latest schema version. If the result is false, wait for a while and check again util the processing time reach 2 * lease.
	// It returns until all servers' versions are equal to the latest version or the ctx is done.
	OwnerCheckAllVersions(ctx goctx.Context, latestVer int64) error
}

SchemaSyncer is used to synchronize schema version between the DDL worker leader and followers through etcd.

func NewMockSchemaSyncer

func NewMockSchemaSyncer() SchemaSyncer

NewMockSchemaSyncer creates a new mock SchemaSyncer.

func NewSchemaSyncer

func NewSchemaSyncer(etcdCli *clientv3.Client, id string) SchemaSyncer

NewSchemaSyncer creates a new SchemaSyncer.