Online DDL: Fail a --in-order-completion migration, if a _prior_ migration within the same context is 'failed' or 'cancelled'

go/test/endtoend/onlineddl/scheduler/onlineddl_scheduler_test.go

@@ -198,7 +198,7 @@ func waitForReadyToComplete(t *testing.T, uuid string, expected bool) {
  case <-ticker.C:
  case <-ctx.Done():
  }
- require.NoError(t, ctx.Err())
+ require.NoError(t, ctx.Err(), "waiting for ready_to_complete=%t for %v", expected, uuid)
  }
 }
 
@@ -422,6 +422,14 @@ func testScheduler(t *testing.T) {
  assert.GreaterOrEqual(t, endTime2, endTime1)
  })
  }
+ testTableCompletionAndStartTimes := func(t *testing.T, uuid1, uuid2 string) {
+ // expect uuid1 to complete before uuid2
+ t.Run("Compare t1, t2 completion times", func(t *testing.T) {
+ endTime1 := testReadTimestamp(t, uuid1, "completed_timestamp")
+ startedTime2 := testReadTimestamp(t, uuid2, "started_timestamp")
+ assert.GreaterOrEqual(t, startedTime2, endTime1)
+ })
+ }
  testAllowConcurrent := func(t *testing.T, name string, uuid string, expect int64) {
  t.Run("verify allow_concurrent: "+name, func(t *testing.T) {
  rs := onlineddl.ReadMigrations(t, &vtParams, uuid)
@@ -434,7 +442,7 @@ func testScheduler(t *testing.T) {
  }
 
  // CREATE
- t.Run("CREATE TABLEs t1, t1", func(t *testing.T) {
+ t.Run("CREATE TABLEs t1, t2", func(t *testing.T) {
  { // The table does not exist
  t1uuid = testOnlineDDLStatement(t, createParams(createT1Statement, ddlStrategy, "vtgate", "just-created", "", false))
  onlineddl.CheckMigrationStatus(t, &vtParams, shards, t1uuid, schema.OnlineDDLStatusComplete)
@@ -1183,6 +1191,36 @@ func testScheduler(t *testing.T) {
  })
  })
  // in-order-completion
+ t.Run("in-order-completion: multiple drops for nonexistent tables and views, sequential", func(t *testing.T) {
+ u, err := schema.CreateOnlineDDLUUID()
+ require.NoError(t, err)
+
+ sqls := []string{
+ fmt.Sprintf("drop table if exists t4_%s", u),
+ fmt.Sprintf("drop view if exists t1_%s", u),
+ fmt.Sprintf("drop table if exists t2_%s", u),
+ fmt.Sprintf("drop view if exists t3_%s", u),
+ }
+ sql := strings.Join(sqls, ";")
+ var vuuids []string
+ t.Run("drop multiple tables and views, in-order-completion", func(t *testing.T) {
+ uuidList := testOnlineDDLStatement(t, createParams(sql, ddlStrategy+" --in-order-completion", "vtctl", "", "", true)) // skip wait
+ vuuids = strings.Split(uuidList, "\n")
+ assert.Equal(t, 4, len(vuuids))
+ for _, uuid := range vuuids {
+ status := onlineddl.WaitForMigrationStatus(t, &vtParams, shards, uuid, normalWaitTime, schema.OnlineDDLStatusComplete, schema.OnlineDDLStatusFailed)
+ fmt.Printf("# Migration status (for debug purposes): <%s>\n", status)
+ onlineddl.CheckMigrationStatus(t, &vtParams, shards, uuid, schema.OnlineDDLStatusComplete)
+ }
+ })
+ require.Equal(t, 4, len(vuuids))
+ for i := range vuuids {
+ if i > 0 {
+ testTableCompletionTimes(t, vuuids[i-1], vuuids[i])
+ testTableCompletionAndStartTimes(t, vuuids[i-1], vuuids[i])
+ }
+ }
+ })
  t.Run("in-order-completion: multiple drops for nonexistent tables and views", func(t *testing.T) {
  u, err := schema.CreateOnlineDDLUUID()
  require.NoError(t, err)
@@ -1212,6 +1250,79 @@ func testScheduler(t *testing.T) {
  }
  }
  })
+
+ t.Run("in-order-completion: bail out on first error", func(t *testing.T) {
+ u, err := schema.CreateOnlineDDLUUID()
+ require.NoError(t, err)
+
+ sqls := []string{
+ fmt.Sprintf("drop table if exists t4_%s", u),
+ fmt.Sprintf("drop view if exists t1_%s", u),
+ fmt.Sprintf("drop table t2_%s", u), // non existent
+ fmt.Sprintf("drop view if exists t3_%s", u),
+ }
+ sql := strings.Join(sqls, ";")
+ var vuuids []string
+ t.Run("apply schema", func(t *testing.T) {
+ uuidList := testOnlineDDLStatement(t, createParams(sql, ddlStrategy+" --in-order-completion", "vtctl", "", "", true)) // skip wait
+ vuuids = strings.Split(uuidList, "\n")
+ assert.Equal(t, 4, len(vuuids))
+ for _, uuid := range vuuids[0:2] {
+ status := onlineddl.WaitForMigrationStatus(t, &vtParams, shards, uuid, normalWaitTime, schema.OnlineDDLStatusComplete, schema.OnlineDDLStatusFailed)
+ fmt.Printf("# Migration status (for debug purposes): <%s>\n", status)
+ onlineddl.CheckMigrationStatus(t, &vtParams, shards, uuid, schema.OnlineDDLStatusComplete)
+ }
+ {
+ uuid := vuuids[2] // the failed one
+ status := onlineddl.WaitForMigrationStatus(t, &vtParams, shards, uuid, normalWaitTime, schema.OnlineDDLStatusComplete, schema.OnlineDDLStatusFailed)
+ fmt.Printf("# Migration status (for debug purposes): <%s>\n", status)
+ onlineddl.CheckMigrationStatus(t, &vtParams, shards, uuid, schema.OnlineDDLStatusFailed)
+ }
+ {
+ uuid := vuuids[3] // should consequently fail without even running
+ status := onlineddl.WaitForMigrationStatus(t, &vtParams, shards, uuid, normalWaitTime, schema.OnlineDDLStatusComplete, schema.OnlineDDLStatusFailed)
+ fmt.Printf("# Migration status (for debug purposes): <%s>\n", status)
+ onlineddl.CheckMigrationStatus(t, &vtParams, shards, uuid, schema.OnlineDDLStatusQueued, schema.OnlineDDLStatusFailed)
+
+ rs := onlineddl.ReadMigrations(t, &vtParams, uuid)
+ require.NotNil(t, rs)
+ for _, row := range rs.Named().Rows {
+ message := row["message"].ToString()
+ require.Contains(t, message, vuuids[2]) // Indicating this migration failed due to vuuids[2] failure
+ }
+ }
+ })
+ testTableCompletionTimes(t, vuuids[0], vuuids[1])
+ testTableCompletionAndStartTimes(t, vuuids[0], vuuids[1])
+ testTableCompletionAndStartTimes(t, vuuids[1], vuuids[2])
+ })
+ t.Run("in-order-completion concurrent: bail out on first error", func(t *testing.T) {
+ sqls := []string{
+ `alter table t1_test force`,
+ `alter table t2_test force`,
+ }
+ sql := strings.Join(sqls, ";")
+ var vuuids []string
+ t.Run("apply schema", func(t *testing.T) {
+ uuidList := testOnlineDDLStatement(t, createParams(sql, ddlStrategy+" --in-order-completion --postpone-completion --allow-concurrent", "vtctl", "", "", true)) // skip wait
+ vuuids = strings.Split(uuidList, "\n")
+ assert.Equal(t, 2, len(vuuids))
+ for _, uuid := range vuuids {
+ waitForReadyToComplete(t, uuid, true)
+ }
+ t.Run("cancel 1st migration", func(t *testing.T) {
+ onlineddl.CheckCancelMigration(t, &vtParams, shards, vuuids[0], true)
+ status := onlineddl.WaitForMigrationStatus(t, &vtParams, shards, vuuids[0], normalWaitTime, schema.OnlineDDLStatusFailed, schema.OnlineDDLStatusCancelled)
+ fmt.Printf("# Migration status (for debug purposes): <%s>\n", status)
+ onlineddl.CheckMigrationStatus(t, &vtParams, shards, vuuids[0], schema.OnlineDDLStatusCancelled)
+ })
+ t.Run("expect 2nd migration to fail", func(t *testing.T) {
+ status := onlineddl.WaitForMigrationStatus(t, &vtParams, shards, vuuids[1], normalWaitTime, schema.OnlineDDLStatusFailed, schema.OnlineDDLStatusCancelled)
+ fmt.Printf("# Migration status (for debug purposes): <%s>\n", status)
+ onlineddl.CheckMigrationStatus(t, &vtParams, shards, vuuids[1], schema.OnlineDDLStatusFailed)
+ })
+ })
+ })
  t.Run("in-order-completion: two new views, one depends on the other", func(t *testing.T) {
  u, err := schema.CreateOnlineDDLUUID()
  require.NoError(t, err)

go/vt/vttablet/onlineddl/executor.go

@@ -2854,6 +2854,31 @@ func (e *Executor) getCompletedMigrationByContextAndSQL(ctx context.Context, onl
  return completedUUID, nil
 }
 
+// readFailedCancelledMigrationsInContextBeforeMigration returns UUIDs for migrations that are failed/cancelled
+// and are in the same context as given migration and _precede_ it chronologically (have lower `id` value)
+func (e *Executor) readFailedCancelledMigrationsInContextBeforeMigration(ctx context.Context, onlineDDL *schema.OnlineDDL) (uuids []string, err error) {
+ if onlineDDL.MigrationContext == "" {
+ // only applies to migrations with an explicit context
+ return nil, nil
+ }
+ query, err := sqlparser.ParseAndBind(sqlSelectFailedCancelledMigrationsInContextBeforeMigration,
+ sqltypes.StringBindVariable(onlineDDL.MigrationContext),
+ sqltypes.StringBindVariable(onlineDDL.UUID),
+ )
+ if err != nil {
+ return nil, err
+ }
+ r, err := e.execQuery(ctx, query)
+ if err != nil {
+ return uuids, err
+ }
+ for _, row := range r.Named().Rows {
+ uuid := row["migration_uuid"].ToString()
+ uuids = append(uuids, uuid)
+ }
+ return uuids, err
+}
+
 // failMigration marks a migration as failed
 func (e *Executor) failMigration(ctx context.Context, onlineDDL *schema.OnlineDDL, withError error) error {
  defer e.triggerNextCheckInterval()
@@ -2865,6 +2890,23 @@ func (e *Executor) failMigration(ctx context.Context, onlineDDL *schema.OnlineDD
  return withError
 }
 
+// validateInOrderMigration checks whether an in-order migration should be forced to fail, either before running or
+// while running.
+// This may happen if a prior migration in the same context has failed or was cancelled.
+func (e *Executor) validateInOrderMigration(ctx context.Context, onlineDDL *schema.OnlineDDL) (wasFailed bool, err error) {
+ if !onlineDDL.StrategySetting().IsInOrderCompletion() {
+ return false, nil
+ }
+ uuids, err := e.readFailedCancelledMigrationsInContextBeforeMigration(ctx, onlineDDL)
+ if err != nil {
+ return false, err
+ }
+ if len(uuids) == 0 {
+ return false, err
+ }
+ return true, e.failMigration(ctx, onlineDDL, fmt.Errorf("migration %v cannot run because prior migration %v in same context has failed/was cancelled", onlineDDL.UUID, uuids[0]))
+}
+
 // analyzeDropDDLActionMigration analyzes a DROP <TABLE|VIEW> migration.
 func (e *Executor) analyzeDropDDLActionMigration(ctx context.Context, onlineDDL *schema.OnlineDDL) error {
  // Schema analysis:
@@ -3384,6 +3426,58 @@ func (e *Executor) executeMigration(ctx context.Context, onlineDDL *schema.Onlin
  return nil
 }
 
+// getNonConflictingMigration finds a single 'ready' migration which does not conflict with running migrations.
+// Conflicts are:
+// - a migration is 'ready' but is not set to run _concurrently_, and there's a running migration that is also non-concurrent
+// - a migration is 'ready' but there's another migration 'running' on the exact same table
+func (e *Executor) getNonConflictingMigration(ctx context.Context) (*schema.OnlineDDL, error) {
+ pendingMigrationsUUIDs, err := e.readPendingMigrationsUUIDs(ctx)
+ if err != nil {
+ return nil, err
+ }
+ r, err := e.execQuery(ctx, sqlSelectReadyMigrations)
+ if err != nil {
+ return nil, err
+ }
+ for _, row := range r.Named().Rows {
+ uuid := row["migration_uuid"].ToString()
+ onlineDDL, migrationRow, err := e.readMigration(ctx, uuid)
+ if err != nil {
+ return nil, err
+ }
+ isImmediateOperation := migrationRow.AsBool("is_immediate_operation", false)
+
+ if conflictFound, _ := e.isAnyConflictingMigrationRunning(onlineDDL); conflictFound {
+ continue // this migration conflicts with a running one
+ }
+ if e.countOwnedRunningMigrations() >= maxConcurrentOnlineDDLs {
+ return nil, nil // too many running migrations
+ }
+ if isImmediateOperation && onlineDDL.StrategySetting().IsInOrderCompletion() {
+ // This migration is immediate: if we run it now, it will complete within a second or two at most.
+ if len(pendingMigrationsUUIDs) > 0 && pendingMigrationsUUIDs[0] != onlineDDL.UUID {
+ continue
+ }
+ }
+ // We will fail an in-order migration if there's _prior_ migrations within the same migration-context
+ // which have failed.
+ if onlineDDL.StrategySetting().IsInOrderCompletion() {
+ wasFailed, err := e.validateInOrderMigration(ctx, onlineDDL)
+ if err != nil {
+ return nil, err
+ }
+ if wasFailed {
+ continue
+ }
+ }
+ // This migration seems good to go
+ return onlineDDL, err
+ }
+ // no non-conflicting migration found...
+ // Either all ready migrations are conflicting, or there are no ready migrations...
+ return nil, nil
+}
+
 // runNextMigration picks up to one 'ready' migration that is able to run, and executes it.
 // Possible scenarios:
 // - no migration is in 'ready' state -- nothing to be done
@@ -3405,47 +3499,7 @@ func (e *Executor) runNextMigration(ctx context.Context) error {
  return nil
  }
 
- // getNonConflictingMigration finds a single 'ready' migration which does not conflict with running migrations.
- // Conflicts are:
- // - a migration is 'ready' but is not set to run _concurrently_, and there's a running migration that is also non-concurrent
- // - a migration is 'ready' but there's another migration 'running' on the exact same table
- getNonConflictingMigration := func() (*schema.OnlineDDL, error) {
- pendingMigrationsUUIDs, err := e.readPendingMigrationsUUIDs(ctx)
- if err != nil {
- return nil, err
- }
- r, err := e.execQuery(ctx, sqlSelectReadyMigrations)
- if err != nil {
- return nil, err
- }
- for _, row := range r.Named().Rows {
- uuid := row["migration_uuid"].ToString()
- onlineDDL, migrationRow, err := e.readMigration(ctx, uuid)
- if err != nil {
- return nil, err
- }
- isImmediateOperation := migrationRow.AsBool("is_immediate_operation", false)
-
- if conflictFound, _ := e.isAnyConflictingMigrationRunning(onlineDDL); conflictFound {
- continue // this migration conflicts with a running one
- }
- if e.countOwnedRunningMigrations() >= maxConcurrentOnlineDDLs {
- continue // too many running migrations
- }
- if isImmediateOperation && onlineDDL.StrategySetting().IsInOrderCompletion() {
- // This migration is immediate: if we run it now, it will complete within a second or two at most.
- if len(pendingMigrationsUUIDs) > 0 && pendingMigrationsUUIDs[0] != onlineDDL.UUID {
- continue
- }
- }
- // This migration seems good to go
- return onlineDDL, err
- }
- // no non-conflicting migration found...
- // Either all ready migrations are conflicting, or there are no ready migrations...
- return nil, nil
- }
- onlineDDL, err := getNonConflictingMigration()
+ onlineDDL, err := e.getNonConflictingMigration(ctx)
  if err != nil {
  return err
  }
@@ -3792,6 +3846,19 @@ func (e *Executor) reviewRunningMigrations(ctx context.Context) (countRunnning i
  _ = e.updateMigrationETASecondsByProgress(ctx, uuid)
  _ = e.updateMigrationLastThrottled(ctx, uuid, time.Unix(s.timeThrottled, 0), s.componentThrottled)
 
+ if onlineDDL.StrategySetting().IsInOrderCompletion() {
+ // We will fail an in-order migration if there's _prior_ migrations within the same migration-context
+ // which have failed.
+ wasFailed, err := e.validateInOrderMigration(ctx, onlineDDL)
+ if err != nil {
+ return err
+ }
+ if wasFailed {
+ return nil
+ }
+ }
+
+ // Check if the migration is ready to cut-over, and proceed to do so if it is.
  isReady, err := e.isVReplMigrationReadyToCutOver(ctx, onlineDDL, s)
  if err != nil {
  _ = e.updateMigrationMessage(ctx, uuid, err.Error())

go/vt/vttablet/onlineddl/schema.go

@@ -303,6 +303,7 @@ const (
  FROM _vt.schema_migrations
  WHERE
  migration_status='running'
+ ORDER BY id
  `
  sqlSelectCompleteMigrationsOnTable = `SELECT
  migration_uuid,
@@ -333,6 +334,18 @@ const (
  WHERE
  migration_status='running'
  AND liveness_timestamp < NOW() - INTERVAL %a MINUTE
+ ORDER BY id
+ `
+ sqlSelectFailedCancelledMigrationsInContextBeforeMigration = `SELECT
+ migration_uuid
+ FROM _vt.schema_migrations
+ WHERE
+ migration_context=%a
+ AND migration_status IN ('failed', 'cancelled')
+ AND id < (
+ SELECT id FROM _vt.schema_migrations WHERE migration_uuid=%a
+ )
+ ORDER BY id
  `
  sqlSelectPendingMigrations = `SELECT
  migration_uuid,
@@ -365,6 +378,7 @@ const (
  NOW() - INTERVAL %a SECOND,
  NOW() - INTERVAL retain_artifacts_seconds SECOND
  )
+ ORDER BY id
  `
  sqlFixCompletedTimestamp = `UPDATE _vt.schema_migrations
  SET