Online DDL: dynamic cut-over threshold via `ALTER VITESS_MIGRATION ..…

…. CUTOVER_THRESHOLD ...` command (vitessio#17126)

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

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

@@ -484,7 +484,7 @@ func testScheduler(t *testing.T) {
 		testTableSequentialTimes(t, t1uuid, t2uuid)
 	})
 	t.Run("Postpone launch CREATE", func(t *testing.T) {
-		t1uuid = testOnlineDDLStatement(t, createParams(createT1IfNotExistsStatement, ddlStrategy+" --postpone-launch", "vtgate", "", "", true)) // skip wait
+		t1uuid = testOnlineDDLStatement(t, createParams(createT1IfNotExistsStatement, ddlStrategy+" --postpone-launch --cut-over-threshold=14s", "vtgate", "", "", true)) // skip wait
 		time.Sleep(2 * time.Second)
 		rs := onlineddl.ReadMigrations(t, &vtParams, t1uuid)
 		require.NotNil(t, rs)
@@ -501,6 +501,10 @@ func testScheduler(t *testing.T) {
 			for _, row := range rs.Named().Rows {
 				postponeLaunch := row.AsInt64("postpone_launch", 0)
 				assert.Equal(t, int64(0), postponeLaunch)
+
+				cutOverThresholdSeconds := row.AsInt64("cutover_threshold_seconds", 0)
+				// Threshold supplied in DDL strategy
+				assert.EqualValues(t, 14, cutOverThresholdSeconds)
 			}
 			status := onlineddl.WaitForMigrationStatus(t, &vtParams, shards, t1uuid, normalWaitTime, schema.OnlineDDLStatusComplete, schema.OnlineDDLStatusFailed)
 			fmt.Printf("# Migration status (for debug purposes): <%s>\n", status)
@@ -580,6 +584,9 @@ func testScheduler(t *testing.T) {
 				assert.Equal(t, int64(1), postponeCompletion)
 			}
 		})
+		t.Run("set cut-over threshold", func(t *testing.T) {
+			onlineddl.CheckSetMigrationCutOverThreshold(t, &vtParams, shards, t1uuid, 17700*time.Millisecond, "")
+		})
 		t.Run("complete", func(t *testing.T) {
 			onlineddl.CheckCompleteMigration(t, &vtParams, shards, t1uuid, true)
 			status := onlineddl.WaitForMigrationStatus(t, &vtParams, shards, t1uuid, normalWaitTime, schema.OnlineDDLStatusComplete, schema.OnlineDDLStatusFailed)
@@ -592,6 +599,11 @@ func testScheduler(t *testing.T) {
 			for _, row := range rs.Named().Rows {
 				postponeCompletion := row.AsInt64("postpone_completion", 0)
 				assert.Equal(t, int64(0), postponeCompletion)
+
+				cutOverThresholdSeconds := row.AsInt64("cutover_threshold_seconds", 0)
+				// Expect 17800*time.Millisecond to be truncated to 17 seconds
+				assert.EqualValues(t, 17, cutOverThresholdSeconds)
+
 				assert.False(t, row["shadow_analyzed_timestamp"].IsNull())
 			}
 		})
@@ -1062,6 +1074,10 @@ func testScheduler(t *testing.T) {
 			for _, row := range rs.Named().Rows {
 				retries := row.AsInt64("retries", 0)
 				assert.Greater(t, retries, int64(0))
+
+				cutOverThresholdSeconds := row.AsInt64("cutover_threshold_seconds", 0)
+				// No explicit cut-over threshold given. Expect the default 10s
+				assert.EqualValues(t, 10, cutOverThresholdSeconds)
 			}
 		})
 	})
@@ -1088,6 +1104,13 @@ func testScheduler(t *testing.T) {
 			executedUUID := testOnlineDDLStatement(t, createParams(trivialAlterT1Statement, ddlStrategy, "vtctl", "", "", true)) // skip wait
 			require.Equal(t, uuid, executedUUID)
 
+			t.Run("set low cut-over threshold", func(t *testing.T) {
+				onlineddl.CheckSetMigrationCutOverThreshold(t, &vtParams, shards, uuid, 2*time.Second, "cut-over min value")
+			})
+			t.Run("set high cut-over threshold", func(t *testing.T) {
+				onlineddl.CheckSetMigrationCutOverThreshold(t, &vtParams, shards, uuid, 2000*time.Second, "cut-over max value")
+			})
+
 			// expect it to complete
 			status := onlineddl.WaitForMigrationStatus(t, &vtParams, shards, uuid, normalWaitTime, schema.OnlineDDLStatusComplete, schema.OnlineDDLStatusFailed)
 			fmt.Printf("# Migration status (for debug purposes): <%s>\n", status)
@@ -1098,6 +1121,10 @@ func testScheduler(t *testing.T) {
 			for _, row := range rs.Named().Rows {
 				retries := row.AsInt64("retries", 0)
 				assert.Greater(t, retries, int64(0))
+
+				cutOverThresholdSeconds := row.AsInt64("cutover_threshold_seconds", 0)
+				// Teh default remains unchanged.
+				assert.EqualValues(t, 10, cutOverThresholdSeconds)
 			}
 		})
 	})

go/test/endtoend/onlineddl/vtgate_util.go

@@ -255,6 +255,16 @@ func CheckForceMigrationCutOver(t *testing.T, vtParams *mysql.ConnParams, shards
 	}
 }
 
+// CheckSetMigrationCutOverThreshold sets the cut-over threshold for a given migration.
+func CheckSetMigrationCutOverThreshold(t *testing.T, vtParams *mysql.ConnParams, shards []cluster.Shard, uuid string, threshold time.Duration, expectError string) {
+	query, err := sqlparser.ParseAndBind("alter vitess_migration %a cutover_threshold %a",
+		sqltypes.StringBindVariable(uuid),
+		sqltypes.StringBindVariable(threshold.String()),
+	)
+	require.NoError(t, err)
+	_ = VtgateExecQuery(t, vtParams, query, expectError)
+}
+
 // CheckMigrationStatus verifies that the migration indicated by given UUID has the given expected status
 func CheckMigrationStatus(t *testing.T, vtParams *mysql.ConnParams, shards []cluster.Shard, uuid string, expectStatuses ...schema.OnlineDDLStatus) bool {
 	ksName := shards[0].PrimaryTablet().VttabletProcess.Keyspace

go/vt/schema/online_ddl.go

@@ -24,6 +24,7 @@ import (
 	"regexp"
 	"strconv"
 	"strings"
+	"time"
 
 	vtrpcpb "vitess.io/vitess/go/vt/proto/vtrpc"
 	"vitess.io/vitess/go/vt/sqlparser"
@@ -116,6 +117,7 @@ type OnlineDDL struct {
 	Retries            int64           `json:"retries,omitempty"`
 	ReadyToComplete    int64           `json:"ready_to_complete,omitempty"`
 	WasReadyToComplete int64           `json:"was_ready_to_complete,omitempty"`
+	CutOverThreshold   time.Duration   `json:"cutover_threshold,omitempty"`
 }
 
 // ParseOnlineDDLStatement parses the given SQL into a statement and returns the action type of the DDL statement, or error

go/vt/sidecardb/schema/onlineddl/schema_migrations.sql

@@ -76,6 +76,7 @@ CREATE TABLE IF NOT EXISTS schema_migrations
     `removed_foreign_key_names`       text             NOT NULL,
     `last_cutover_attempt_timestamp`  timestamp        NULL DEFAULT NULL,
     `force_cutover`                   tinyint unsigned NOT NULL DEFAULT '0',
+    `cutover_threshold_seconds`       int unsigned     NOT NULL DEFAULT '0',
     PRIMARY KEY (`id`),
     UNIQUE KEY `uuid_idx` (`migration_uuid`),
     KEY `keyspace_shard_idx` (`keyspace`(64), `shard`(64)),

go/vt/sqlparser/ast.go

@@ -491,11 +491,12 @@ type (
 
 	// AlterMigration represents a ALTER VITESS_MIGRATION statement
 	AlterMigration struct {
-		Type   AlterMigrationType
-		UUID   string
-		Expire string
-		Ratio  *Literal
-		Shards string
+		Type      AlterMigrationType
+		UUID      string
+		Expire    string
+		Ratio     *Literal
+		Threshold string
+		Shards    string
 	}
 
 	// AlterTable represents a ALTER TABLE statement.

go/vt/sqlparser/ast_format.go

@@ -322,8 +322,13 @@ func (node *AlterMigration) Format(buf *TrackedBuffer) {
 		alterType = "force_cutover"
 	case ForceCutOverAllMigrationType:
 		alterType = "force_cutover all"
+	case SetCutOverThresholdMigrationType:
+		alterType = "cutover_threshold"
 	}
 	buf.astPrintf(node, " %#s", alterType)
+	if node.Threshold != "" {
+		buf.astPrintf(node, " '%#s'", node.Threshold)
+	}
 	if node.Expire != "" {
 		buf.astPrintf(node, " expire '%#s'", node.Expire)
 	}

go/vt/sqlparser/constants.go

@@ -915,6 +915,7 @@ const (
 	UnthrottleAllMigrationType
 	ForceCutOverMigrationType
 	ForceCutOverAllMigrationType
+	SetCutOverThresholdMigrationType
 )
 
 // ColumnStorage constants

go/vt/sqlparser/keywords.go

@@ -205,6 +205,7 @@ var keywords = []keyword{
 	{"current_timestamp", CURRENT_TIMESTAMP},
 	{"current_user", CURRENT_USER},
 	{"cursor", UNUSED},
+	{"cutover_threshold", CUTOVER_THRESHOLD},
 	{"data", DATA},
 	{"database", DATABASE},
 	{"databases", DATABASES},

go/vt/sqlparser/parse_test.go

@@ -2482,6 +2482,8 @@ var (
 		input: "alter vitess_migration force_cutover all",
 	}, {
 		input: "alter vitess_migration '9748c3b7_7fdb_11eb_ac2c_f875a4d24e90' force_cutover",
+	}, {
+		input: "alter vitess_migration '9748c3b7_7fdb_11eb_ac2c_f875a4d24e90' cutover_threshold '17s'",
 	}, {
 		input:  "alter vitess_migration '9748c3b7_7fdb_11eb_ac2c_f875a4d24e90' FORCE_CUTOVER",
 		output: "alter vitess_migration '9748c3b7_7fdb_11eb_ac2c_f875a4d24e90' force_cutover",