Merge branch 'master' into meiji163/parallel-repl

.gitignore

@@ -3,3 +3,4 @@
 /libexec/
 /.vendor/
 .idea/
+*.tmp

go.mod

@@ -11,9 +11,9 @@ require (
 	github.com/stretchr/testify v1.9.0
 	github.com/testcontainers/testcontainers-go v0.34.0
 	golang.org/x/net v0.24.0
-	golang.org/x/sync v0.8.0
-	golang.org/x/term v0.19.0
-	golang.org/x/text v0.14.0
+	golang.org/x/sync v0.10.0
+	golang.org/x/term v0.27.0
+	golang.org/x/text v0.21.0
 )
 
 require (
@@ -66,7 +66,7 @@ require (
 	go.opentelemetry.io/otel/metric v1.24.0 // indirect
 	go.opentelemetry.io/otel/trace v1.24.0 // indirect
 	go.uber.org/atomic v1.7.0 // indirect
-	golang.org/x/crypto v0.22.0 // indirect
-	golang.org/x/sys v0.21.0 // indirect
+	golang.org/x/crypto v0.31.0 // indirect
+	golang.org/x/sys v0.28.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -183,8 +183,8 @@ go.uber.org/zap v1.18.1/go.mod h1:xg/QME4nWcxGxrpdeYfq7UvYrLh66cuVKdrbD1XF/NI=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
-golang.org/x/crypto v0.22.0 h1:g1v0xeRhjcugydODzvb3mEM9SQ0HGp9s/nh3COQ/C30=
-golang.org/x/crypto v0.22.0/go.mod h1:vr6Su+7cTlO45qkww3VDJlzDn0ctJvRgYbC2NvXHt+M=
+golang.org/x/crypto v0.31.0 h1:ihbySMvVjLAeSH1IbfcRTkD/iNscyz8rGzjF/E5hV6U=
+golang.org/x/crypto v0.31.0/go.mod h1:kDsLvtWBEx7MV9tJOj9bnXsPbxwJQ6csT/x4KIN4Ssk=
 golang.org/x/exp v0.0.0-20181106170214-d68db9428509/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/lint v0.0.0-20190930215403-16217165b5de/go.mod h1:6SW0HCj/g11FgYtHlgUYUwCkIfeOF89ocIRzGO/8vkc=
 golang.org/x/mod v0.2.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
@@ -199,8 +199,8 @@ golang.org/x/net v0.24.0/go.mod h1:2Q7sJY5mzlzWjKtYUEXSlBWCdyaioyXzRB2RtU8KVE8=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.8.0 h1:3NFvSEYkUoMifnESzZl15y791HH1qU2xm6eCJU5ZPXQ=
-golang.org/x/sync v0.8.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
+golang.org/x/sync v0.10.0 h1:3NQrjDixjgGwUOCaF8w2+VYHv0Ve/vGYSbdkTa98gmQ=
+golang.org/x/sync v0.10.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190916202348-b4ddaad3f8a3/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
@@ -211,15 +211,15 @@ golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBc
 golang.org/x/sys v0.8.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.11.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.15.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-golang.org/x/sys v0.21.0 h1:rF+pYz3DAGSQAxAu1CbC7catZg4ebC4UIeIhKxBZvws=
-golang.org/x/sys v0.21.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-golang.org/x/term v0.19.0 h1:+ThwsDv+tYfnJFhF4L8jITxu1tdTWRTZpdsWgEgjL6Q=
-golang.org/x/term v0.19.0/go.mod h1:2CuTdWZ7KHSQwUzKva0cbMg6q2DMI3Mmxp+gKJbskEk=
+golang.org/x/sys v0.28.0 h1:Fksou7UEQUWlKvIdsqzJmUmCX3cZuD2+P3XyyzwMhlA=
+golang.org/x/sys v0.28.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/term v0.27.0 h1:WP60Sv1nlK1T6SupCHbXzSaN0b9wUmsPoRS9b61A23Q=
+golang.org/x/term v0.27.0/go.mod h1:iMsnZpn0cago0GOrHO2+Y7u7JPn5AylBrcoWkElMTSM=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
-golang.org/x/text v0.14.0 h1:ScX5w1eTa3QqT8oi6+ziP7dTV1S2+ALU0bI+0zXKWiQ=
-golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
+golang.org/x/text v0.21.0 h1:zyQAAkrwaneQ066sspRyJaG9VNi/YJ1NfzcGB3hZ/qo=
+golang.org/x/text v0.21.0/go.mod h1:4IBbMaMmOPCJ8SecivzSH54+73PCFmPWxNTLm+vZkEQ=
 golang.org/x/time v0.0.0-20220210224613-90d013bbcef8 h1:vVKdlvoWBphwdxWKrFZEuM0kGgGLxUOYcY4U/2Vjg44=
 golang.org/x/time v0.0.0-20220210224613-90d013bbcef8/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=

go/base/context.go

@@ -197,6 +197,7 @@ type MigrationContext struct {
 	CurrentLag                             int64
 	currentProgress                        uint64
 	etaNanoseonds                          int64
+	EtaRowsPerSecond                       int64
 	ThrottleHTTPIntervalMillis             int64
 	ThrottleHTTPStatusCode                 int64
 	ThrottleHTTPTimeoutMillis              int64

go/cmd/gh-ost/main.go

@@ -107,7 +107,7 @@ func main() {
 	chunkSize := flag.Int64("chunk-size", 1000, "amount of rows to handle in each iteration (allowed range: 10-100,000)")
 	dmlBatchSize := flag.Int64("dml-batch-size", 10, "batch size for DML events to apply in a single transaction (range 1-100)")
 	defaultRetries := flag.Int64("default-retries", 60, "Default number of retries for various operations before panicking")
-	cutOverLockTimeoutSeconds := flag.Int64("cut-over-lock-timeout-seconds", 3, "Max number of seconds to hold locks on tables while attempting to cut-over (retry attempted when lock exceeds timeout)")
+	cutOverLockTimeoutSeconds := flag.Int64("cut-over-lock-timeout-seconds", 3, "Max number of seconds to hold locks on tables while attempting to cut-over (retry attempted when lock exceeds timeout) or attempting instant DDL")
 	niceRatio := flag.Float64("nice-ratio", 0, "force being 'nice', imply sleep time per chunk time; range: [0.0..100.0]. Example values: 0 is aggressive. 1: for every 1ms spent copying rows, sleep additional 1ms (effectively doubling runtime); 0.7: for every 10ms spend in a rowcopy chunk, spend 7ms sleeping immediately after")
 	flag.IntVar(&migrationContext.NumWorkers, "workers", 8, "Number of concurrent workers for applying DML events. Each worker uses one goroutine.")
 

go/logic/applier.go

@@ -257,6 +257,15 @@ func (this *Applier) ValidateOrDropExistingTables() error {
 func (this *Applier) AttemptInstantDDL() error {
 	query := this.generateInstantDDLQuery()
 	this.migrationContext.Log.Infof("INSTANT DDL query is: %s", query)
+
+	// Reuse cut-over-lock-timeout from regular migration process to reduce risk
+	// in situations where there may be long-running transactions.
+	tableLockTimeoutSeconds := this.migrationContext.CutOverLockTimeoutSeconds * 2
+	this.migrationContext.Log.Infof("Setting LOCK timeout as %d seconds", tableLockTimeoutSeconds)
+	lockTimeoutQuery := fmt.Sprintf(`set /* gh-ost */ session lock_wait_timeout:=%d`, tableLockTimeoutSeconds)
+	if _, err := this.db.Exec(lockTimeoutQuery); err != nil {
+		return err
+	}
 	// We don't need a trx, because for instant DDL the SQL mode doesn't matter.
 	_, err := this.db.Exec(query)
 	return err

go/logic/inspect.go

@@ -22,7 +22,8 @@ import (
 	"github.com/openark/golib/sqlutils"
 )
 
-const startSlavePostWaitMilliseconds = 500 * time.Millisecond
+const startReplicationPostWait = 250 * time.Millisecond
+const startReplicationMaxWait = 2 * time.Second
 
 // Inspector reads data from the read-MySQL-server (typically a replica, but can be the master)
 // It is used for gaining initial status and structure, and later also follow up on progress and changelog
@@ -302,12 +303,50 @@ func (this *Inspector) restartReplication() error {
 	if startError != nil {
 		return startError
 	}
-	time.Sleep(startSlavePostWaitMilliseconds)
+
+	// loop until replication is running unless we hit a max timeout.
+	startTime := time.Now()
+	for {
+		replicationRunning, err := this.validateReplicationRestarted()
+		if err != nil {
+			return fmt.Errorf("Failed to validate if replication had been restarted: %w", err)
+		}
+		if replicationRunning {
+			break
+		}
+		if time.Since(startTime) > startReplicationMaxWait {
+			return fmt.Errorf("Replication did not restart within the maximum wait time of %s", startReplicationMaxWait)
+		}
+		this.migrationContext.Log.Debugf("Replication not yet restarted, waiting...")
+		time.Sleep(startReplicationPostWait)
+	}
 
 	this.migrationContext.Log.Debugf("Replication restarted")
 	return nil
 }
 
+// validateReplicationRestarted checks that the Slave_IO_Running and Slave_SQL_Running are both 'Yes'
+// returns true if both are 'Yes', false otherwise
+func (this *Inspector) validateReplicationRestarted() (bool, error) {
+	errNotRunning := fmt.Errorf("Replication not running on %s", this.connectionConfig.Key.String())
+	query := `show /* gh-ost */ slave status`
+	err := sqlutils.QueryRowsMap(this.db, query, func(rowMap sqlutils.RowMap) error {
+		if rowMap.GetString("Slave_IO_Running") != "Yes" || rowMap.GetString("Slave_SQL_Running") != "Yes" {
+			return errNotRunning
+		}
+		return nil
+	})
+
+	if err != nil {
+		// If the error is that replication is not running, return that and not an error
+		if errors.Is(err, errNotRunning) {
+			return false, nil
+		}
+		return false, err
+	}
+	return true, nil
+}
+
 // applyBinlogFormat sets ROW binlog format and restarts replication to make
 // the replication thread apply it.
 func (this *Inspector) applyBinlogFormat() error {
@@ -589,6 +628,7 @@ func (this *Inspector) applyColumnTypes(databaseName, tableName string, columnsL
 		columnName := m.GetString("COLUMN_NAME")
 		columnType := m.GetString("COLUMN_TYPE")
 		columnOctetLength := m.GetUint("CHARACTER_OCTET_LENGTH")
+		extra := m.GetString("EXTRA")
 		for _, columnsList := range columnsLists {
 			column := columnsList.GetColumn(columnName)
 			if column == nil {
@@ -621,6 +661,9 @@ func (this *Inspector) applyColumnTypes(databaseName, tableName string, columnsL
 				column.Type = sql.BinaryColumnType
 				column.BinaryOctetLength = columnOctetLength
 			}
+			if strings.Contains(extra, " GENERATED") {
+				column.IsVirtual = true
+			}
 			if charset := m.GetString("CHARACTER_SET_NAME"); charset != "" {
 				column.Charset = charset
 			}

go/logic/migrator.go

@@ -826,11 +826,18 @@ func (this *Migrator) initiateStatus() {
 	this.printStatus(ForcePrintStatusAndHintRule)
 	ticker := time.NewTicker(time.Second)
 	defer ticker.Stop()
+	var previousCount int64
 	for range ticker.C {
 		if atomic.LoadInt64(&this.finishedMigrating) > 0 {
 			return
 		}
 		go this.printStatus(HeuristicPrintStatusRule)
+		totalCopied := atomic.LoadInt64(&this.migrationContext.TotalRowsCopied)
+		if previousCount > 0 {
+			copiedThisLoop := totalCopied - previousCount
+			atomic.StoreInt64(&this.migrationContext.EtaRowsPerSecond, copiedThisLoop)
+		}
+		previousCount = totalCopied
 	}
 }
 
@@ -932,9 +939,20 @@ func (this *Migrator) getMigrationETA(rowsEstimate int64) (eta string, duration
 		duration = 0
 	} else if progressPct >= 0.1 {
 		totalRowsCopied := this.migrationContext.GetTotalRowsCopied()
-		elapsedRowCopySeconds := this.migrationContext.ElapsedRowCopyTime().Seconds()
-		totalExpectedSeconds := elapsedRowCopySeconds * float64(rowsEstimate) / float64(totalRowsCopied)
-		etaSeconds := totalExpectedSeconds - elapsedRowCopySeconds
+		etaRowsPerSecond := atomic.LoadInt64(&this.migrationContext.EtaRowsPerSecond)
+		var etaSeconds float64
+		// If there is data available on our current row-copies-per-second rate, use it.
+		// Otherwise we can fallback to the total elapsed time and extrapolate.
+		// This is going to be less accurate on a longer copy as the insert rate
+		// will tend to slow down.
+		if etaRowsPerSecond > 0 {
+			remainingRows := float64(rowsEstimate) - float64(totalRowsCopied)
+			etaSeconds = remainingRows / float64(etaRowsPerSecond)
+		} else {
+			elapsedRowCopySeconds := this.migrationContext.ElapsedRowCopyTime().Seconds()
+			totalExpectedSeconds := elapsedRowCopySeconds * float64(rowsEstimate) / float64(totalRowsCopied)
+			etaSeconds = totalExpectedSeconds - elapsedRowCopySeconds
+		}
 		if etaSeconds >= 0 {
 			duration = time.Duration(etaSeconds) * time.Second
 		} else {

go/logic/migrator_test.go

@@ -215,6 +215,15 @@ func TestMigratorGetMigrationStateAndETA(t *testing.T) {
 		require.Equal(t, "4h29m44s", eta)
 		require.Equal(t, "4h29m44s", etaDuration.String())
 	}
+	{
+		// Test using rows-per-second added data.
+		migrationContext.TotalRowsCopied = 456
+		migrationContext.EtaRowsPerSecond = 100
+		state, eta, etaDuration := migrator.getMigrationStateAndETA(123456)
+		require.Equal(t, "migrating", state)
+		require.Equal(t, "20m30s", eta)
+		require.Equal(t, "20m30s", etaDuration.String())
+	}
 	{
 		migrationContext.TotalRowsCopied = 456
 		state, eta, etaDuration := migrator.getMigrationStateAndETA(456)

go/sql/builder.go

@@ -546,6 +546,12 @@ func NewDMLUpdateQueryBuilder(databaseName, tableName string, tableColumns, shar
 	if uniqueKeyColumns.Len() == 0 {
 		return nil, fmt.Errorf("no unique key columns found in NewDMLUpdateQueryBuilder")
 	}
+	// If unique key contains virtual columns, those column won't be in sharedColumns
+	// which only contains non-virtual columns
+	nonVirtualUniqueKeyColumns := uniqueKeyColumns.FilterBy(func(column Column) bool { return !column.IsVirtual })
+	if !nonVirtualUniqueKeyColumns.IsSubsetOf(sharedColumns) {
+		return nil, fmt.Errorf("unique key columns is not a subset of shared columns in NewDMLUpdateQueryBuilder")
+	}
 	databaseName = EscapeName(databaseName)
 	tableName = EscapeName(tableName)
 	setClause, err := BuildSetPreparedClause(mappedSharedColumns)
@@ -580,11 +586,6 @@ func NewDMLUpdateQueryBuilder(databaseName, tableName string, tableColumns, shar
 // BuildQuery builds the arguments array for a DML event UPDATE query.
 // It returns the query string, the shared arguments array, and the unique key arguments array.
 func (b *DMLUpdateQueryBuilder) BuildQuery(valueArgs, whereArgs []interface{}) (string, []interface{}, []interface{}, error) {
-	// TODO: move this check back to `NewDMLUpdateQueryBuilder()`, needs fix on generated columns.
-	if !b.uniqueKeyColumns.IsSubsetOf(b.sharedColumns) {
-		return "", nil, nil, fmt.Errorf("unique key columns is not a subset of shared columns in DMLUpdateQueryBuilder")
-	}
-
 	sharedArgs := make([]interface{}, 0, b.sharedColumns.Len())
 	for _, column := range b.sharedColumns.Columns() {
 		tableOrdinal := b.tableColumns.Ordinals[column.Name]

go/sql/builder_test.go

@@ -688,9 +688,7 @@ func TestBuildDMLUpdateQuery(t *testing.T) {
 	{
 		sharedColumns := NewColumnList([]string{"id", "name", "position", "age"})
 		uniqueKeyColumns := NewColumnList([]string{"age", "surprise"})
-		builder, err := NewDMLUpdateQueryBuilder(databaseName, tableName, tableColumns, sharedColumns, sharedColumns, uniqueKeyColumns)
-		require.NoError(t, err)
-		_, _, _, err = builder.BuildQuery(valueArgs, whereArgs)
+		_, err := NewDMLUpdateQueryBuilder(databaseName, tableName, tableColumns, sharedColumns, sharedColumns, uniqueKeyColumns)
 		require.Error(t, err)
 	}
 	{

go/sql/types.go

@@ -40,6 +40,7 @@ type CharacterSetConversion struct {
 type Column struct {
 	Name                 string
 	IsUnsigned           bool
+	IsVirtual            bool
 	Charset              string
 	Type                 ColumnType
 	EnumValues           string
@@ -244,6 +245,16 @@ func (this *ColumnList) IsSubsetOf(other *ColumnList) bool {
 	return true
 }
 
+func (this *ColumnList) FilterBy(f func(Column) bool) *ColumnList {
+	filteredCols := make([]Column, 0, len(this.columns))
+	for _, column := range this.columns {
+		if f(column) {
+			filteredCols = append(filteredCols, column)
+		}
+	}
+	return &ColumnList{Ordinals: this.Ordinals, columns: filteredCols}
+}
+
 func (this *ColumnList) Len() int {
 	return len(this.columns)
 }

localtests/docker-compose.yml

@@ -1,31 +1,25 @@
 services:
   mysql-primary:
-    image: mysql:8.0.39
+    image: $TEST_MYSQL_IMAGE
     container_name: mysql-primary
     command: --server-id=1 --log-bin=mysql-bin --binlog-format=row --gtid-mode=ON --enforce-gtid-consistency=ON
-    # volumes:
-    #   - /var/lib/mysql
     environment:
       MYSQL_ROOT_PASSWORD: opensesame
+      MYSQL_ROOT_HOST: '%'
       MYSQL_DATABASE: test
-      MYSQL_USER: repl
-      MYSQL_PASSWORD: repl
       MYSQL_TCP_PORT: 3307
     ports:
       - '3307:3307'
     expose:
       - '3307'
   mysql-replica:
-    image: mysql:8.0.39
+    image: $TEST_MYSQL_IMAGE
     container_name: mysql-replica
-    command: --server-id=2 --log-bin=mysql-bin --binlog-format=row --gtid-mode=ON --enforce-gtid-consistency=ON
-    # volumes:
-    #   - /var/lib/mysql
+    command: --server-id=2 --log-bin=mysql-bin --binlog-format=row --gtid-mode=ON --enforce-gtid-consistency=ON --log-slave-updates=ON
     environment:
       MYSQL_ROOT_PASSWORD: opensesame
+      MYSQL_ROOT_HOST: '%'
       MYSQL_DATABASE: test
-      MYSQL_USER: repl
-      MYSQL_PASSWORD: repl
       MYSQL_TCP_PORT: 3308
     ports:
       - '3308:3308'

localtests/generated-columns-unique/create.sql

@@ -3,6 +3,7 @@ create table gh_ost_test (
   id int auto_increment,
   `idb` varchar(36) CHARACTER SET utf8mb4 GENERATED ALWAYS AS (json_unquote(json_extract(`jsonobj`,_utf8mb4'$._id'))) STORED NOT NULL,
   `jsonobj` json NOT NULL,
+  updated datetime DEFAULT NULL,
   PRIMARY KEY (`id`,`idb`)
 ) auto_increment=1;
 
@@ -25,6 +26,11 @@ begin
   insert into gh_ost_test (id, jsonobj) values (null, '{"_id":13}');
   insert into gh_ost_test (id, jsonobj) values (null, '{"_id":17}');
   insert into gh_ost_test (id, jsonobj) values (null, '{"_id":19}');
-  insert into gh_ost_test (id, jsonobj) values (null, '{"_id":23}');
-  insert into gh_ost_test (id, jsonobj) values (null, '{"_id":27}');
+
+  update gh_ost_test set updated=NOW() where idb=5;
+  update gh_ost_test set updated=NOW() where idb=7;
+  update gh_ost_test set updated=NOW() where idb=11;
+  update gh_ost_test set updated=NOW() where idb=13;
+  update gh_ost_test set updated=NOW() where idb=17;
+  update gh_ost_test set updated=NOW() where idb=19;
 end ;;

localtests/generated-columns/create.sql

@@ -27,4 +27,6 @@ begin
   insert into gh_ost_test (id, a, b) values (null, 2,0);
   insert into gh_ost_test (id, a, b) values (null, 2,1);
   insert into gh_ost_test (id, a, b) values (null, 2,2);
+  update gh_ost_test set b=b+1 where id < 5;
+  update gh_ost_test set b=b-1 where id >= 5;
 end ;;