Schema Tracking Refactor: Merge schema-tracking in health-streamer in…

…to schema.Engine (#13121) * test: add test to verify the expectations of health stream Signed-off-by: Manan Gupta <manan@planetscale.com> * test: augment the test to also test the case where views are enabled in vttablets Signed-off-by: Manan Gupta <manan@planetscale.com> * feat: use the schema engine notifier to run the reload in health-streamer Signed-off-by: Manan Gupta <manan@planetscale.com> * feat: deprecate the flag controlling the interval of health-streamer reload Signed-off-by: Manan Gupta <manan@planetscale.com> * test: augment test to verify schema tracking works for alters in views as well Signed-off-by: Manan Gupta <manan@planetscale.com> * feat: add a view table type and augment loadTable function to assign it correctly Signed-off-by: Manan Gupta <manan@planetscale.com> * feat: change health streamer to use the tables got from the schemaEngine instead of detecting the schema changes on its own Signed-off-by: Manan Gupta <manan@planetscale.com> * feat: make the schema engine capable of storing the table and view information in a database Signed-off-by: Manan Gupta <manan@planetscale.com> * feat: remove unused functions Signed-off-by: Manan Gupta <manan@planetscale.com> * feat: fix health streamer tests Signed-off-by: Manan Gupta <manan@planetscale.com> * test: fix tests by also deleting the tablet record for the tablets that are removed Signed-off-by: Manan Gupta <manan@planetscale.com> * feat: fix deadlocks and incorrect writes from health-streamer Signed-off-by: Manan Gupta <manan@planetscale.com> * feat: improve how we start health streamer and engine Signed-off-by: Manan Gupta <manan@planetscale.com> * feat: use the newly introduced field Signed-off-by: Manan Gupta <manan@planetscale.com> * feat: use sqlparser.string to get the escaped table name Signed-off-by: Manan Gupta <manan@planetscale.com> * test: fix the default configuration test's expectation Signed-off-by: Manan Gupta <manan@planetscale.com> * test: add the new tables to the expected output of tests Signed-off-by: Manan Gupta <manan@planetscale.com> * test: fix test expectation to match MySQL 8.0 behaviour Signed-off-by: Manan Gupta <manan@planetscale.com> * feat: fix schema change test Signed-off-by: Manan Gupta <manan@planetscale.com> * feat: fix state manager test Signed-off-by: Manan Gupta <manan@planetscale.com> * feat: use the same flag for the context in schema-engine Signed-off-by: Manan Gupta <manan@planetscale.com> * test: refactor test to use a single stream call Signed-off-by: Manan Gupta <manan@planetscale.com> * feat: revert changes to json marshal in config Signed-off-by: Manan Gupta <manan@planetscale.com> * feat: fix health stream timeout test Signed-off-by: Manan Gupta <manan@planetscale.com> * feat: refactor engine notifier to send tables instead of strings Signed-off-by: Manan Gupta <manan@planetscale.com> * feat: add tests for all the functions in the db.go file and fix a couple of them Signed-off-by: Manan Gupta <manan@planetscale.com> * feat: refactor code and fix a couple of bugs Signed-off-by: Manan Gupta <manan@planetscale.com> * test: add more tests for the reload database logic Signed-off-by: Manan Gupta <manan@planetscale.com> * test: fix schema version test Signed-off-by: Manan Gupta <manan@planetscale.com> * test: added more tests for all the schema.engine functions Signed-off-by: Manan Gupta <manan@planetscale.com> * test: fix engine test flakiness Signed-off-by: Manan Gupta <manan@planetscale.com> * test: add health-streamer test Signed-off-by: Manan Gupta <manan@planetscale.com> * feat: fix data race in fakedb Signed-off-by: Manan Gupta <manan@planetscale.com> * test: add header comments to tests Signed-off-by: Manan Gupta <manan@planetscale.com> * feat: rename views table columns to table_schema and table_name Signed-off-by: Manan Gupta <manan@planetscale.com> * feat: fix detectViewChange query Signed-off-by: Manan Gupta <manan@planetscale.com> * feat: fix the summary Signed-off-by: Manan Gupta <manan@planetscale.com> --------- Signed-off-by: Manan Gupta <manan@planetscale.com>
vitessio · May 31, 2023 · 9e892eb · 9e892eb
1 parent a4b8e26
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diff --git a/changelog/17.0/17.0.0/summary.md b/changelog/17.0/17.0.0/summary.md
@@ -22,6 +22,7 @@
     - [Support for MySQL 8.0 `binlog_transaction_compression`](#binlog-compression)
   - **[VTTablet](#vttablet)**
     - [VTTablet: Initializing all replicas with super_read_only](#vttablet-initialization)
+    - [Vttablet Schema Reload Timeout](#vttablet-schema-reload-timeout) 
     - [Settings pool enabled](#settings-pool)
   - **[VReplication](#VReplication)**
     - [Support for the `noblob` binlog row image mode](#noblob)
@@ -319,6 +320,10 @@ This is even more important if you are running Vitess on the vitess-operator.
 You must ensure your `init_db.sql` is up-to-date with the new default for `v17.0.0`.
 The default file can be found in `./config/init_db.sql`.
 
+#### <a id="vttablet-schema-reload-timeout"/> Vttablet Schema Reload Timeout
+
+A new flag, `--schema-change-reload-timeout` has been added to timeout the reload of the schema that Vttablet does periodically. This is required because sometimes this operation can get stuck after MySQL restarts, etc. More details available in the issue https://github.com/vitessio/vitess/issues/13001.
+
 #### <a id="settings-pool"/> Settings Pool
 This was introduced in v15 and it enables pooling the connection with modified connection settings.
 To know more what it does read the [v15 release notes](https://github.com/vitessio/vitess/releases/tag/v15.0.0) or the [blog](https://vitess.io/blog/2023-03-27-connection-pooling-in-vitess/) or [docs](https://vitess.io/docs/17.0/reference/query-serving/reserved-conn/)
@@ -385,6 +390,8 @@ This could be a breaking change for grpc api users based on how they have implem
   `schema_change_check_interval` now **only** accepts Go duration values. This affects `vtctld`.
 * The flag `durability_policy` is no longer used by vtctld. Instead it reads the durability policies for all keyspaces from the topology server.
 * The flag `use_super_read_only` is deprecated and will be removed in a later release. This affects `vttablet`.
+* The flag `queryserver-config-schema-change-signal-interval` is deprecated and will be removed in a later release. This affects `vttablet`.
+  Schema-tracking has been refactored in this release to not use polling anymore, therefore the signal interval isn't required anymore.
 
 In `vttablet` various flags that took float values as seconds have updated to take the standard duration syntax as well.
 Float-style parsing is now deprecated and will be removed in a later release.

diff --git a/go/flags/endtoend/vttablet.txt b/go/flags/endtoend/vttablet.txt
@@ -233,7 +233,6 @@ Usage of vttablet:
       --queryserver-config-query-pool-waiter-cap int                     query server query pool waiter limit, this is the maximum number of queries that can be queued waiting to get a connection (default 5000)
       --queryserver-config-query-timeout duration                        query server query timeout (in seconds), this is the query timeout in vttablet side. If a query takes more than this timeout, it will be killed. (default 30s)
       --queryserver-config-schema-change-signal                          query server schema signal, will signal connected vtgates that schema has changed whenever this is detected. VTGates will need to have -schema_change_signal enabled for this to work (default true)
-      --queryserver-config-schema-change-signal-interval duration        query server schema change signal interval defines at which interval the query server shall send schema updates to vtgate. (default 5s)
       --queryserver-config-schema-reload-time duration                   query server schema reload time, how often vttablet reloads schemas from underlying MySQL instance in seconds. vttablet keeps table schemas in its own memory and periodically refreshes it from MySQL. This config controls the reload time. (default 30m0s)
       --queryserver-config-stream-buffer-size int                        query server stream buffer size, the maximum number of bytes sent from vttablet for each stream call. It's recommended to keep this value in sync with vtgate's stream_buffer_size. (default 32768)
       --queryserver-config-stream-pool-size int                          query server stream connection pool size, stream pool is used by stream queries: queries that return results to client in a streaming fashion (default 200)
@@ -269,7 +268,7 @@ Usage of vttablet:
       --s3_backup_storage_root string                                    root prefix for all backup-related object names.
       --s3_backup_tls_skip_verify_cert                                   skip the 'certificate is valid' check for SSL connections.
       --sanitize_log_messages                                            Remove potentially sensitive information in tablet INFO, WARNING, and ERROR log messages such as query parameters.
-      --schema-change-reload-timeout duration                            query server schema change signal reload timeout, this is how long to wait for the signaled schema reload operation to complete before giving up (default 30s)
+      --schema-change-reload-timeout duration                            query server schema change reload timeout, this is how long to wait for the signaled schema reload operation to complete before giving up (default 30s)
       --schema-version-max-age-seconds int                               max age of schema version records to kept in memory by the vreplication historian
       --security_policy string                                           the name of a registered security policy to use for controlling access to URLs - empty means allow all for anyone (built-in policies: deny-all, read-only)
       --service_map strings                                              comma separated list of services to enable (or disable if prefixed with '-') Example: grpc-queryservice

diff --git a/go/mysql/fakesqldb/server.go b/go/mysql/fakesqldb/server.go
@@ -124,6 +124,10 @@ type DB struct {
 	// if fakesqldb is asked to serve queries or query patterns that it has not been explicitly told about it will
 	// error out by default. However if you set this flag then any unmatched query results in an empty result
 	neverFail atomic.Bool
+
+	// lastError stores the last error in returning a query result.
+	lastErrorMu sync.Mutex
+	lastError   error
 }
 
 // QueryHandler is the interface used by the DB to simulate executed queries
@@ -176,6 +180,7 @@ func New(t testing.TB) *DB {
 		connections:              make(map[uint32]*mysql.Conn),
 		queryPatternUserCallback: make(map[*regexp.Regexp]func(string)),
 		patternData:              make(map[string]exprResult),
+		lastErrorMu:              sync.Mutex{},
 	}
 
 	db.Handler = db
@@ -245,6 +250,13 @@ func (db *DB) CloseAllConnections() {
 	}
 }
 
+// LastError gives the last error the DB ran into
+func (db *DB) LastError() error {
+	db.lastErrorMu.Lock()
+	defer db.lastErrorMu.Unlock()
+	return db.lastError
+}
+
 // WaitForClose should be used after CloseAllConnections() is closed and
 // you want to provoke a MySQL client error with errno 2006.
 //
@@ -342,7 +354,14 @@ func (db *DB) WarningCount(c *mysql.Conn) uint16 {
 }
 
 // HandleQuery is the default implementation of the QueryHandler interface
-func (db *DB) HandleQuery(c *mysql.Conn, query string, callback func(*sqltypes.Result) error) error {
+func (db *DB) HandleQuery(c *mysql.Conn, query string, callback func(*sqltypes.Result) error) (err error) {
+	defer func() {
+		if err != nil {
+			db.lastErrorMu.Lock()
+			db.lastError = err
+			db.lastErrorMu.Unlock()
+		}
+	}()
 	if db.allowAll.Load() {
 		return callback(&sqltypes.Result{})
 	}
@@ -413,7 +432,7 @@ func (db *DB) HandleQuery(c *mysql.Conn, query string, callback func(*sqltypes.R
 		return callback(&sqltypes.Result{})
 	}
 	// Nothing matched.
-	err := fmt.Errorf("fakesqldb:: query: '%s' is not supported on %v",
+	err = fmt.Errorf("fakesqldb:: query: '%s' is not supported on %v",
 		sqlparser.TruncateForUI(query), db.name)
 	log.Errorf("Query not found: %s", sqlparser.TruncateForUI(query))
 

diff --git a/go/test/endtoend/cluster/cluster_process.go b/go/test/endtoend/cluster/cluster_process.go
@@ -929,6 +929,46 @@ func (cluster *LocalProcessCluster) StreamTabletHealth(ctx context.Context, vtta
 	return responses, nil
 }
 
+// StreamTabletHealthUntil invokes a HealthStream on a local cluster Vttablet and
+// returns the responses. It waits until a certain condition is met. The amount of time to wait is an input that it takes.
+func (cluster *LocalProcessCluster) StreamTabletHealthUntil(ctx context.Context, vttablet *Vttablet, timeout time.Duration, condition func(shr *querypb.StreamHealthResponse) bool) error {
+	tablet, err := cluster.VtctlclientGetTablet(vttablet)
+	if err != nil {
+		return err
+	}
+
+	conn, err := tabletconn.GetDialer()(tablet, grpcclient.FailFast(false))
+	if err != nil {
+		return err
+	}
+
+	conditionSuccess := false
+	timeoutExceeded := false
+	go func() {
+		time.Sleep(timeout)
+		timeoutExceeded = true
+	}()
+
+	err = conn.StreamHealth(ctx, func(shr *querypb.StreamHealthResponse) error {
+		if condition(shr) {
+			conditionSuccess = true
+		}
+		if timeoutExceeded || conditionSuccess {
+			return io.EOF
+		}
+		return nil
+	})
+
+	if conditionSuccess {
+		return nil
+	}
+
+	if timeoutExceeded {
+		return errors.New("timeout exceed while waiting for the condition in StreamHealth")
+	}
+	return err
+}
+
 func (cluster *LocalProcessCluster) VtctlclientGetTablet(tablet *Vttablet) (*topodatapb.Tablet, error) {
 	result, err := cluster.VtctlclientProcess.ExecuteCommandWithOutput("GetTablet", "--", tablet.Alias)
 	if err != nil {

diff --git a/go/test/endtoend/cluster/vtctldclient_process.go b/go/test/endtoend/cluster/vtctldclient_process.go
@@ -93,6 +93,18 @@ func VtctldClientProcessInstance(hostname string, grpcPort int, tmpDirectory str
 	return vtctldclient
 }
 
+// PlannedReparentShard executes vtctlclient command to make specified tablet the primary for the shard.
+func (vtctldclient *VtctldClientProcess) PlannedReparentShard(Keyspace string, Shard string, alias string) (err error) {
+	output, err := vtctldclient.ExecuteCommandWithOutput(
+		"PlannedReparentShard",
+		fmt.Sprintf("%s/%s", Keyspace, Shard),
+		"--new-primary", alias)
+	if err != nil {
+		log.Errorf("error in PlannedReparentShard output %s, err %s", output, err.Error())
+	}
+	return err
+}
+
 // CreateKeyspace executes the vtctl command to create a keyspace
 func (vtctldclient *VtctldClientProcess) CreateKeyspace(keyspaceName string, sidecarDBName string) (err error) {
 	var output string

diff --git a/go/test/endtoend/tabletmanager/custom_rule_topo_test.go b/go/test/endtoend/tabletmanager/custom_rule_topo_test.go
@@ -119,5 +119,5 @@ func TestTopoCustomRule(t *testing.T) {
 	// Reset the VtTabletExtraArgs
 	clusterInstance.VtTabletExtraArgs = []string{}
 	// Tear down custom processes
-	killTablets(t, rTablet)
+	killTablets(rTablet)
 }
diff --git a/go/test/endtoend/tabletmanager/main_test.go b/go/test/endtoend/tabletmanager/main_test.go
@@ -95,6 +95,7 @@ func TestMain(m *testing.M) {
 		// List of users authorized to execute vschema ddl operations
 		clusterInstance.VtGateExtraArgs = []string{
 			"--vschema_ddl_authorized_users=%",
+			"--enable-views",
 			"--discovery_low_replication_lag", tabletUnhealthyThreshold.String(),
 		}
 		// Set extra tablet args for lock timeout

diff --git a/go/test/endtoend/tabletmanager/tablet_health_test.go b/go/test/endtoend/tabletmanager/tablet_health_test.go
@@ -27,12 +27,12 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"k8s.io/utils/strings/slices"
 
 	"vitess.io/vitess/go/json2"
 	"vitess.io/vitess/go/mysql"
 	"vitess.io/vitess/go/test/endtoend/cluster"
 	"vitess.io/vitess/go/test/endtoend/utils"
-
 	querypb "vitess.io/vitess/go/vt/proto/query"
 	topodatapb "vitess.io/vitess/go/vt/proto/topodata"
 )
@@ -87,13 +87,15 @@ func TestTabletReshuffle(t *testing.T) {
 	err = clusterInstance.VtctlclientProcess.ExecuteCommand("Backup", rTablet.Alias)
 	assert.Error(t, err, "cannot perform backup without my.cnf")
 
-	killTablets(t, rTablet)
+	killTablets(rTablet)
 }
 
 func TestHealthCheck(t *testing.T) {
 	// Add one replica that starts not initialized
 	defer cluster.PanicHandler(t)
 	ctx := context.Background()
+	clusterInstance.DisableVTOrcRecoveries(t)
+	defer clusterInstance.EnableVTOrcRecoveries(t)
 
 	rTablet := clusterInstance.NewVttabletInstance("replica", 0, "")
 
@@ -192,7 +194,141 @@ func TestHealthCheck(t *testing.T) {
 	}
 
 	// Manual cleanup of processes
-	killTablets(t, rTablet)
+	killTablets(rTablet)
+}
+
+// TestHealthCheckSchemaChangeSignal tests the tables and views, which report their schemas have changed in the output of a StreamHealth.
+func TestHealthCheckSchemaChangeSignal(t *testing.T) {
+	// Add one replica that starts not initialized
+	defer cluster.PanicHandler(t)
+	ctx := context.Background()
+
+	vtParams := clusterInstance.GetVTParams(keyspaceName)
+	conn, err := mysql.Connect(ctx, &vtParams)
+	require.NoError(t, err)
+	defer conn.Close()
+
+	// Make sure the primary is the primary when the test starts.
+	// This state should be ensured before we actually test anything.
+	checkTabletType(t, primaryTablet.Alias, "PRIMARY")
+
+	// Run a bunch of DDL queries and verify that the tables/views changed show up in the health stream.
+	// These tests are for the part where `--queryserver-enable-views` flag is not set.
+	verifyHealthStreamSchemaChangeSignals(t, conn, &primaryTablet, false)
+
+	// We start a new vttablet, this time with `--queryserver-enable-views` flag specified.
+	tempTablet := clusterInstance.NewVttabletInstance("replica", 0, "")
+	// Start Mysql Processes and return connection
+	_, err = cluster.StartMySQLAndGetConnection(ctx, tempTablet, username, clusterInstance.TmpDirectory)
+	require.NoError(t, err)
+	oldArgs := clusterInstance.VtTabletExtraArgs
+	clusterInstance.VtTabletExtraArgs = append(clusterInstance.VtTabletExtraArgs, "--queryserver-enable-views")
+	defer func() {
+		clusterInstance.VtTabletExtraArgs = oldArgs
+	}()
+	// start vttablet process, should be in SERVING state as we already have a primary.
+	err = clusterInstance.StartVttablet(tempTablet, "SERVING", false, cell, keyspaceName, hostname, shardName)
+	require.NoError(t, err)
+
+	defer func() {
+		// Restore the primary tablet back to the original.
+		err = clusterInstance.VtctldClientProcess.PlannedReparentShard(keyspaceName, shardName, primaryTablet.Alias)
+		require.NoError(t, err)
+		// Manual cleanup of processes
+		killTablets(tempTablet)
+	}()
+
+	// Now we reparent the cluster to the new tablet we have.
+	err = clusterInstance.VtctldClientProcess.PlannedReparentShard(keyspaceName, shardName, tempTablet.Alias)
+	require.NoError(t, err)
+
+	checkTabletType(t, tempTablet.Alias, "PRIMARY")
+	// Run a bunch of DDL queries and verify that the tables/views changed show up in the health stream.
+	// These tests are for the part where `--queryserver-enable-views` flag is set.
+	verifyHealthStreamSchemaChangeSignals(t, conn, tempTablet, true)
+}
+
+func verifyHealthStreamSchemaChangeSignals(t *testing.T, vtgateConn *mysql.Conn, primaryTablet *cluster.Vttablet, viewsEnabled bool) {
+	var streamErr error
+	wg := sync.WaitGroup{}
+	wg.Add(1)
+	ranOnce := false
+	finished := false
+	ch := make(chan *querypb.StreamHealthResponse)
+	go func() {
+		defer wg.Done()
+		streamErr = clusterInstance.StreamTabletHealthUntil(context.Background(), primaryTablet, 30*time.Second, func(shr *querypb.StreamHealthResponse) bool {
+			ranOnce = true
+			// If we are finished, then close the channel and end the stream.
+			if finished {
+				close(ch)
+				return true
+			}
+			// Put the response in the channel.
+			ch <- shr
+			return false
+		})
+	}()
+	// The test becomes flaky if we run the DDL immediately after starting the above go routine because the client for the Stream
+	// sometimes isn't registered by the time DDL runs, and it misses the update we get. To prevent this situation, we wait for one Stream packet
+	// to have returned. Once we know we received a Stream packet, then we know that we are registered for the health stream and can execute the DDL.
+	for i := 0; i < 30; i++ {
+		if ranOnce {
+			break
+		}
+		time.Sleep(1 * time.Second)
+	}
+
+	verifyTableDDLSchemaChangeSignal(t, vtgateConn, ch, "CREATE TABLE `area` (`id` int NOT NULL, `country` varchar(30), PRIMARY KEY (`id`))", "area")
+	verifyTableDDLSchemaChangeSignal(t, vtgateConn, ch, "CREATE TABLE `area2` (`id` int NOT NULL, PRIMARY KEY (`id`))", "area2")
+	verifyViewDDLSchemaChangeSignal(t, vtgateConn, ch, "CREATE VIEW v2 as select * from t1", viewsEnabled)
+	verifyTableDDLSchemaChangeSignal(t, vtgateConn, ch, "ALTER TABLE `area` ADD COLUMN name varchar(30) NOT NULL", "area")
+	verifyTableDDLSchemaChangeSignal(t, vtgateConn, ch, "DROP TABLE `area2`", "area2")
+	verifyViewDDLSchemaChangeSignal(t, vtgateConn, ch, "ALTER VIEW v2 as select id from t1", viewsEnabled)
+	verifyViewDDLSchemaChangeSignal(t, vtgateConn, ch, "DROP VIEW v2", viewsEnabled)
+	verifyTableDDLSchemaChangeSignal(t, vtgateConn, ch, "DROP TABLE `area`", "area")
+
+	finished = true
+	wg.Wait()
+	require.NoError(t, streamErr)
+}
+
+func verifyTableDDLSchemaChangeSignal(t *testing.T, vtgateConn *mysql.Conn, ch chan *querypb.StreamHealthResponse, query string, table string) {
+	_, err := vtgateConn.ExecuteFetch(query, 10000, false)
+	require.NoError(t, err)
+
+	timeout := time.After(15 * time.Second)
+	for {
+		select {
+		case shr := <-ch:
+			if shr != nil && shr.RealtimeStats != nil && slices.Contains(shr.RealtimeStats.TableSchemaChanged, table) {
+				return
+			}
+		case <-timeout:
+			t.Errorf("didn't get the correct tables changed in stream response until timeout")
+		}
+	}
+}
+
+func verifyViewDDLSchemaChangeSignal(t *testing.T, vtgateConn *mysql.Conn, ch chan *querypb.StreamHealthResponse, query string, viewsEnabled bool) {
+	_, err := vtgateConn.ExecuteFetch(query, 10000, false)
+	require.NoError(t, err)
+
+	timeout := time.After(15 * time.Second)
+	for {
+		select {
+		case shr := <-ch:
+			listToUse := shr.RealtimeStats.TableSchemaChanged
+			if viewsEnabled {
+				listToUse = shr.RealtimeStats.ViewSchemaChanged
+			}
+			if shr != nil && shr.RealtimeStats != nil && slices.Contains(listToUse, "v2") {
+				return
+			}
+		case <-timeout:
+			t.Errorf("didn't get the correct views changed in stream response until timeout")
+		}
+	}
 }
 
 func checkHealth(t *testing.T, port int, shouldError bool) {
@@ -247,6 +383,8 @@ func TestHealthCheckDrainedStateDoesNotShutdownQueryService(t *testing.T) {
 
 	//Wait if tablet is not in service state
 	defer cluster.PanicHandler(t)
+	clusterInstance.DisableVTOrcRecoveries(t)
+	defer clusterInstance.EnableVTOrcRecoveries(t)
 	err := rdonlyTablet.VttabletProcess.WaitForTabletStatus("SERVING")
 	require.NoError(t, err)
 
@@ -284,14 +422,15 @@ func TestHealthCheckDrainedStateDoesNotShutdownQueryService(t *testing.T) {
 	checkHealth(t, rdonlyTablet.HTTPPort, false)
 }
 
-func killTablets(t *testing.T, tablets ...*cluster.Vttablet) {
+func killTablets(tablets ...*cluster.Vttablet) {
 	var wg sync.WaitGroup
 	for _, tablet := range tablets {
 		wg.Add(1)
 		go func(tablet *cluster.Vttablet) {
 			defer wg.Done()
 			_ = tablet.VttabletProcess.TearDown()
 			_ = tablet.MysqlctlProcess.Stop()
+			_ = clusterInstance.VtctlclientProcess.ExecuteCommand("DeleteTablet", tablet.Alias)
 		}(tablet)
 	}
 	wg.Wait()