migration

Documentation

Overview

Package migration contains the logic for running online schema changes.

Index

• type CutOver
  • func NewCutOver(db *sql.DB, config []*cutoverConfig, feed *repl.Client, ...) (*CutOver, error)
  • func (c *CutOver) Run(ctx context.Context) error
• type Migration
  • func (m *Migration) Run() error
• type Runner
  • func NewRunner(m *Migration) (*Runner, error)
  • func (r *Runner) Cancel()
  • func (r *Runner) Close() error
  • func (r *Runner) DumpCheckpoint(ctx context.Context) error
  • func (r *Runner) Progress() status.Progress
  • func (r *Runner) Run(ctx context.Context) error
  • func (r *Runner) SetLogger(logger loggers.Advanced)
  • func (r *Runner) SetMetricsSink(sink metrics.Sink)
  • func (r *Runner) Status() string

Types

type CutOver

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

func NewCutOver

func NewCutOver(db *sql.DB, config []*cutoverConfig, feed *repl.Client, dbConfig *dbconn.DBConfig, logger loggers.Advanced) (*CutOver, error)

NewCutOver contains the logic to perform the final cut over. It can cutover multiple tables at once based on config. A replication feed which is used to ensure consistency before the cut over.

func (*CutOver) Run

func (c *CutOver) Run(ctx context.Context) error

type Migration

type Migration struct {
	Host                 string        `name:"host" help:"Hostname" optional:"" default:"127.0.0.1:3306"`
	Username             string        `name:"username" help:"User" optional:"" default:"spirit"`
	Password             string        `name:"password" help:"Password" optional:"" default:"spirit"`
	Database             string        `name:"database" help:"Database" optional:"" default:"test"`
	Table                string        `name:"table" help:"Table" optional:""`
	Alter                string        `name:"alter" help:"The alter statement to run on the table" optional:""`
	Threads              int           `name:"threads" help:"Number of concurrent threads for copy and checksum tasks" optional:"" default:"4"`
	TargetChunkTime      time.Duration `name:"target-chunk-time" help:"The target copy time for each chunk" optional:"" default:"500ms"`
	ReplicaDSN           string        `name:"replica-dsn" help:"A DSN for a replica which (if specified) will be used for lag checking." optional:""`
	ReplicaMaxLag        time.Duration `` /* 127-byte string literal not displayed */
	LockWaitTimeout      time.Duration `name:"lock-wait-timeout" help:"The DDL lock_wait_timeout required for checksum and cutover" optional:"" default:"30s"`
	SkipDropAfterCutover bool          `name:"skip-drop-after-cutover" help:"Keep old table after completing cutover" optional:"" default:"false"`
	DeferCutOver         bool          `name:"defer-cutover" help:"Defer cutover (and checksum) until sentinel table is dropped" optional:"" default:"false"`
	ForceKill            bool          `` /* 152-byte string literal not displayed */
	Strict               bool          `name:"strict" help:"Exit on --alter mismatch when incomplete migration is detected" optional:"" default:"false"`
	Statement            string        `name:"statement" help:"The SQL statement to run (replaces --table and --alter)" optional:"" default:""`
	// TLS Configuration
	TLSMode            string `` /* 162-byte string literal not displayed */
	TLSCertificatePath string `name:"tls-ca" help:"Path to custom TLS CA certificate file" optional:""`

	// Experimental features
	// These are no longer hidden, we document them.
	EnableExperimentalBufferedCopy bool `` /* 154-byte string literal not displayed */

	EnableExperimentalLinting bool     `` /* 129-byte string literal not displayed */
	EnableExperimentalLinters []string `name:"enable-experimental-linters" help:"Experimental linters to enable (default \"all\")" optional:""`
	ExperimentalLinterConfig  []string `` /* 133-byte string literal not displayed */
	ExperimentalLintOnly      bool     `name:"experimental-lint-only" help:"Exit after executing linters" optional:"" default:"false"`

	// Hidden options for now (supports more obscure cash/sq usecases)
	InterpolateParams bool `name:"interpolate-params" help:"Enable interpolate params for DSN" optional:"" default:"false" hidden:""`
	// Used for tests so we can concurrently execute without issues even though
	// the sentinel name is shared. Basically it will be true here, but false
	// in the tests unless we set it explicitly true.
	RespectSentinel bool `name:"respect-sentinel" help:"Look for sentinel table to exist and block if it does" optional:"" default:"true" hidden:""`
}

func (*Migration) Run

func (m *Migration) Run() error

type Runner

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

func NewRunner

func NewRunner(m *Migration) (*Runner, error)

func (*Runner) Cancel

func (r *Runner) Cancel()

func (*Runner) Close

func (r *Runner) Close() error

func (*Runner) DumpCheckpoint

func (r *Runner) DumpCheckpoint(ctx context.Context) error

DumpCheckpoint is called approximately every minute. It writes the current state of the migration to the checkpoint table, which can be used in recovery. Previously resuming from checkpoint would always restart at the copier, but it can now also resume at the checksum phase.

func (*Runner) Progress

func (r *Runner) Progress() status.Progress

func (*Runner) Run

func (r *Runner) Run(ctx context.Context) error

func (*Runner) SetLogger

func (r *Runner) SetLogger(logger loggers.Advanced)

func (*Runner) SetMetricsSink

func (r *Runner) SetMetricsSink(sink metrics.Sink)

func (*Runner) Status

func (r *Runner) Status() string