syncer

Documentation

Index

• Constants
• Variables
• type SchemaSyncer
  • func NewSchemaSyncer(etcdCli *clientv3.Client, id string) SchemaSyncer

Constants

const (
	// InitialVersion is the initial schema version for every server.
	// It's exported for testing.
	InitialVersion = "0"
)

Variables

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
)

Types

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 context.Context) error
	// UpdateSelfVersion updates the current version to the self path on etcd.
	UpdateSelfVersion(ctx context.Context, jobID int64, version int64) error
	// OwnerUpdateGlobalVersion updates the latest version to the global path on etcd until updating is successful or the ctx is done.
	OwnerUpdateGlobalVersion(ctx context.Context, version int64) error
	// GlobalVersionCh gets the chan for watching global version.
	GlobalVersionCh() clientv3.WatchChan
	// WatchGlobalSchemaVer watches the global schema version.
	WatchGlobalSchemaVer(ctx context.Context)
	// 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 context.Context) error
	// OwnerCheckAllVersions checks whether all followers' schema version are equal to
	// the latest schema version. (exclude the isolated TiDB)
	// It returns until all servers' versions are equal to the latest version.
	OwnerCheckAllVersions(ctx context.Context, jobID int64, latestVer int64) error
	// Close ends SchemaSyncer.
	Close()
}

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

func NewSchemaSyncer

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

NewSchemaSyncer creates a new SchemaSyncer.