Online DDL: better support for subsecond --force-cut-over-after DDL…

… strategy flag value. (#16635)

Signed-off-by: Shlomi Noach <[email protected]>

go/vt/schema/ddl_strategy_test.go

@@ -328,6 +328,13 @@ func TestParseDDLStrategy(t *testing.T) {
 			runtimeOptions:    "",
 			forceCutOverAfter: 3 * time.Minute,
 		},
+		{
+			strategyVariable:  "vitess --force-cut-over-after=-1ms",
+			strategy:          DDLStrategyVitess,
+			options:           "--force-cut-over-after=-1ms",
+			runtimeOptions:    "",
+			forceCutOverAfter: -1 * time.Millisecond,
+		},
 		{
 			strategyVariable: "vitess --force-cut-over-after=r3m",
 			strategy:         DDLStrategyVitess,

go/vt/vttablet/onlineddl/executor.go

@@ -3845,7 +3845,7 @@ func (e *Executor) reviewRunningMigrations(ctx context.Context) (countRunnning i
 		uuid := row["migration_uuid"].ToString()
 		cutoverAttempts := row.AsInt64("cutover_attempts", 0)
 		sinceLastCutoverAttempt := time.Second * time.Duration(row.AsInt64("seconds_since_last_cutover_attempt", 0))
-		sinceReadyToComplete := time.Second * time.Duration(row.AsInt64("seconds_since_ready_to_complete", 0))
+		sinceReadyToComplete := time.Microsecond * time.Duration(row.AsInt64("microseconds_since_ready_to_complete", 0))
 		onlineDDL, migrationRow, err := e.readMigration(ctx, uuid)
 		if err != nil {
 			return countRunnning, cancellable, err

go/vt/vttablet/onlineddl/executor_test.go

@@ -481,6 +481,38 @@ func TestShouldCutOverAccordingToBackoff(t *testing.T) {
 			expectShouldCutOver:      false,
 			expectShouldForceCutOver: false,
 		},
+		{
+			name:                     "zero since ready",
+			cutoverAttempts:          3,
+			forceCutOverAfter:        time.Second,
+			sinceReadyToComplete:     0,
+			expectShouldCutOver:      false,
+			expectShouldForceCutOver: false,
+		},
+		{
+			name:                     "zero since read, zero cut-over-after",
+			cutoverAttempts:          3,
+			forceCutOverAfter:        0,
+			sinceReadyToComplete:     0,
+			expectShouldCutOver:      false,
+			expectShouldForceCutOver: false,
+		},
+		{
+			name:                     "microsecond",
+			cutoverAttempts:          3,
+			forceCutOverAfter:        time.Microsecond,
+			sinceReadyToComplete:     time.Millisecond,
+			expectShouldCutOver:      true,
+			expectShouldForceCutOver: true,
+		},
+		{
+			name:                     "microsecond, not ready",
+			cutoverAttempts:          3,
+			forceCutOverAfter:        time.Millisecond,
+			sinceReadyToComplete:     time.Microsecond,
+			expectShouldCutOver:      false,
+			expectShouldForceCutOver: false,
+		},
 		{
 			name:                     "cutover-after overrides backoff",
 			cutoverAttempts:          3,

go/vt/vttablet/onlineddl/schema.go

@@ -304,7 +304,7 @@ const (
 			postpone_completion,
 			force_cutover,
 			cutover_attempts,
-			ifnull(timestampdiff(second, ready_to_complete_timestamp, now()), 0) as seconds_since_ready_to_complete,
+			ifnull(timestampdiff(microsecond, ready_to_complete_timestamp, now(6)), 0) as microseconds_since_ready_to_complete,
 			ifnull(timestampdiff(second, last_cutover_attempt_timestamp, now()), 0) as seconds_since_last_cutover_attempt,
 			timestampdiff(second, started_timestamp, now()) as elapsed_seconds
 		FROM _vt.schema_migrations