ci: pool-related test flakyness

go/test/endtoend/cluster/cluster_process.go

@@ -32,6 +32,7 @@ import (
 	"strconv"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"syscall"
 	"testing"
 	"time"
@@ -189,18 +190,20 @@ func (shard *Shard) Replica() *Vttablet {
 	return nil
 }
 
-// CtrlCHandler handles the teardown for the ctrl-c.
-func (cluster *LocalProcessCluster) CtrlCHandler() {
+// SetupCtrlCHandler handles the teardown for the ctrl-c.
+func (cluster *LocalProcessCluster) SetupCtrlCHandler() {
 	cluster.Context, cluster.CancelFunc = context.WithCancel(context.Background())
 
-	c := make(chan os.Signal, 2)
-	signal.Notify(c, os.Interrupt, syscall.SIGTERM)
-	select {
-	case <-c:
-		cluster.Teardown()
-		os.Exit(0)
-	case <-cluster.Done():
-	}
+	go func() {
+		c := make(chan os.Signal, 2)
+		signal.Notify(c, os.Interrupt, syscall.SIGTERM)
+		select {
+		case <-c:
+			cluster.Teardown()
+			os.Exit(0)
+		case <-cluster.Done():
+		}
+	}()
 }
 
 // StartTopo starts topology server
@@ -715,7 +718,7 @@ func (cluster *LocalProcessCluster) NewVtgateInstance() *VtgateProcess {
 // NewBareCluster instantiates a new cluster and does not assume existence of any of the vitess processes
 func NewBareCluster(cell string, hostname string) *LocalProcessCluster {
 	cluster := &LocalProcessCluster{Cell: cell, Hostname: hostname, mx: new(sync.Mutex), DefaultCharset: "utf8mb4"}
-	go cluster.CtrlCHandler()
+	cluster.SetupCtrlCHandler()
 
 	cluster.OriginalVTDATAROOT = os.Getenv("VTDATAROOT")
 	cluster.CurrentVTDATAROOT = path.Join(os.Getenv("VTDATAROOT"), fmt.Sprintf("vtroot_%d", cluster.GetAndReservePort()))
@@ -941,28 +944,28 @@ func (cluster *LocalProcessCluster) StreamTabletHealthUntil(ctx context.Context,
 		return err
 	}
 
-	conditionSuccess := false
-	timeoutExceeded := false
+	var conditionSuccess atomic.Bool
+	var timeoutExceeded atomic.Bool
 	go func() {
 		time.Sleep(timeout)
-		timeoutExceeded = true
+		timeoutExceeded.Store(true)
 	}()
 
 	err = conn.StreamHealth(ctx, func(shr *querypb.StreamHealthResponse) error {
 		if condition(shr) {
-			conditionSuccess = true
+			conditionSuccess.Store(true)
 		}
-		if timeoutExceeded || conditionSuccess {
+		if timeoutExceeded.Load() || conditionSuccess.Load() {
 			return io.EOF
 		}
 		return nil
 	})
 
-	if conditionSuccess {
+	if conditionSuccess.Load() {
 		return nil
 	}
 
-	if timeoutExceeded {
+	if timeoutExceeded.Load() {
 		return errors.New("timeout exceed while waiting for the condition in StreamHealth")
 	}
 	return err

go/test/endtoend/tabletmanager/tablet_health_test.go

@@ -23,6 +23,7 @@ import (
 	"net/http"
 	"slices"
 	"sync"
+	"sync/atomic"
 	"testing"
 	"time"
 
@@ -250,17 +251,19 @@ func TestHealthCheckSchemaChangeSignal(t *testing.T) {
 
 func verifyHealthStreamSchemaChangeSignals(t *testing.T, vtgateConn *mysql.Conn, primaryTablet *cluster.Vttablet, viewsEnabled bool) {
 	var streamErr error
-	wg := sync.WaitGroup{}
+	var wg sync.WaitGroup
+	var ranOnce atomic.Bool
+	var finished atomic.Bool
+
 	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
+			ranOnce.Store(true)
 			// If we are finished, then close the channel and end the stream.
-			if finished {
+			if finished.Load() {
 				close(ch)
 				return true
 			}
@@ -272,13 +275,14 @@ func verifyHealthStreamSchemaChangeSignals(t *testing.T, vtgateConn *mysql.Conn,
 	// 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
-		}
+	for i := 0; i < 30 && !ranOnce.Load(); i++ {
 		time.Sleep(1 * time.Second)
 	}
 
+	if !ranOnce.Load() {
+		t.Fatalf("HealthCheck did not ran?")
+	}
+
 	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)
@@ -288,7 +292,7 @@ func verifyHealthStreamSchemaChangeSignals(t *testing.T, vtgateConn *mysql.Conn,
 	verifyViewDDLSchemaChangeSignal(t, vtgateConn, ch, "DROP VIEW v2", viewsEnabled)
 	verifyTableDDLSchemaChangeSignal(t, vtgateConn, ch, "DROP TABLE `area`", "area")
 
-	finished = true
+	finished.Store(true)
 	wg.Wait()
 	require.NoError(t, streamErr)
 }

go/test/endtoend/vtgate/unsharded/main_test.go

@@ -131,7 +131,6 @@ BEGIN
 	insert into allDefaults () values ();
     select * from allDefaults;
 	delete from allDefaults;
-    set autocommit = 0;
 END;
 
 CREATE PROCEDURE in_parameter(IN val int)

go/vt/vttablet/endtoend/streamtimeout/healthstream_test.go

@@ -17,23 +17,31 @@ limitations under the License.
 package streamtimeout
 
 import (
-	"fmt"
+	"context"
 	"slices"
 	"testing"
 	"time"
 
 	"github.com/stretchr/testify/require"
 
+	"vitess.io/vitess/go/mysql"
 	querypb "vitess.io/vitess/go/vt/proto/query"
 	"vitess.io/vitess/go/vt/vttablet/endtoend/framework"
 )
 
 // TestSchemaChangeTimedout ensures that the timeout functionality is working properly
 // to prevent queries from hanging up and causing a mutex to be locked forever.
 func TestSchemaChangeTimedout(t *testing.T) {
+	const TableName = "vitess_healthstream"
+
 	client := framework.NewClient()
 	reloadEstimatedTime := 2 * time.Second
 
+	err := cluster.SimulateMySQLHang()
+	require.NoError(t, err)
+
+	defer cluster.StopSimulateMySQLHang()
+
 	ch := make(chan []string, 100)
 	go func(ch chan []string) {
 		client.StreamHealth(func(response *querypb.StreamHealthResponse) error {
@@ -44,39 +52,22 @@ func TestSchemaChangeTimedout(t *testing.T) {
 		})
 	}(ch)
 
-	// We will set up the MySQLHang simulation.
-	// To avoid flakiness, we will retry the setup if the health_streamer sends a notification before the MySQLHang is simulated.
-	attempt := 1
-	var tableName string
-loop:
-	for {
-		tableName = fmt.Sprintf("vitess_sc%d", attempt)
-
-		// change the schema to trigger the health_streamer to send a notification at a later time.
-		_, err := client.Execute("create table "+tableName+"(id bigint primary key)", nil)
-		require.NoError(t, err)
+	// get a clean connection that skips toxyproxy to be able to change the schema in the underlying DB
+	cleanParams := cluster.MySQLCleanConnParams()
+	cleanConn, err := mysql.Connect(context.Background(), &cleanParams)
+	require.NoError(t, err)
+	defer cleanConn.Close()
 
-		// start simulating a mysql stall until a query issued by the health_streamer would hang.
-		err = cluster.SimulateMySQLHang()
-		require.NoError(t, err)
+	// change the schema to trigger the health_streamer to send a notification at a later time.
+	_, err = cleanConn.ExecuteFetch("create table "+TableName+"(id bigint primary key)", -1, false)
+	require.NoError(t, err)
 
-		select {
-		case <-ch: // get the schema notification
-			// The health_streamer can send a notification between the time the schema is changed and the mysql stall is simulated.
-			// In this rare case, we must retry the same setup again.
-			cluster.StopSimulateMySQLHang()
-			attempt++
-
-			if attempt > 5 {
-				t.Errorf("failed to setup MySQLHang even after several attempts")
-				return
-			}
-			t.Logf("retrying setup for attempt %d", attempt)
-		case <-time.After(reloadEstimatedTime):
-			break loop
-		}
+	select {
+	case <-ch: // get the schema notification
+		t.Fatalf("received an schema change event from the HealthStreamer (is toxyproxy working?)")
+	case <-time.After(reloadEstimatedTime):
+		// Good, continue
 	}
-	defer cluster.StopSimulateMySQLHang()
 
 	// We will wait for the health_streamer to attempt sending a notification.
 	// It's important to keep in mind that the total wait time after the simulation should be shorter than the reload timeout.
@@ -87,7 +78,7 @@ loop:
 	time.Sleep(reloadInterval)
 
 	// pause simulating the mysql stall to allow the health_streamer to resume.
-	err := cluster.PauseSimulateMySQLHang()
+	err = cluster.PauseSimulateMySQLHang()
 	require.NoError(t, err)
 
 	// wait for the health_streamer to complete retrying the notification.
@@ -97,7 +88,7 @@ loop:
 	for {
 		select {
 		case res := <-ch: // get the schema notification
-			if slices.Contains(res, tableName) {
+			if slices.Contains(res, TableName) {
 				return
 			}
 		case <-timeout:

go/vt/vttest/local_cluster.go

@@ -290,6 +290,18 @@ func (db *LocalCluster) MySQLAppDebugConnParams() mysql.ConnParams {
 	return connParams
 }
 
+// MySQLCleanConnParams returns connection params that can be used to connect
+// directly to MySQL, even if there's a toxyproxy instance on the way.
+func (db *LocalCluster) MySQLCleanConnParams() mysql.ConnParams {
+	mysqlctl := db.mysql
+	if toxiproxy, ok := mysqlctl.(*Toxiproxyctl); ok {
+		mysqlctl = toxiproxy.mysqlctl
+	}
+	connParams := mysqlctl.Params(db.DbName())
+	connParams.Charset = db.Config.Charset
+	return connParams
+}
+
 // SimulateMySQLHang simulates a scenario where the backend MySQL stops all data from flowing through.
 // Please ensure to `defer db.StopSimulateMySQLHang()` after calling this method.
 func (db *LocalCluster) SimulateMySQLHang() error {