fix: txpool size change to update normal and foundrows pool

Signed-off-by: Harshit Gangal <harshit@planetscale.com>

go/vt/vttablet/endtoend/call_test.go

@@ -20,7 +20,6 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
-
 	"github.com/stretchr/testify/require"
 
 	"vitess.io/vitess/go/vt/vttablet/endtoend/framework"
@@ -136,6 +135,7 @@ func TestCallProcedureLeakTx(t *testing.T) {
 
 func TestCallProcedureChangedTx(t *testing.T) {
 	client := framework.NewClient()
+	defer client.Release()
 
 	_, err := client.Execute(`call proc_tx_begin()`, nil)
 	require.EqualError(t, err, "Transaction not concluded inside the stored procedure, leaking transaction from stored procedure is not allowed (CallerID: dev)")

go/vt/vttablet/endtoend/config_test.go

@@ -23,7 +23,6 @@ import (
 	"time"
 
 	"github.com/stretchr/testify/assert"
-
 	"github.com/stretchr/testify/require"
 
 	"vitess.io/vitess/go/sqltypes"
@@ -73,6 +72,48 @@ func TestStreamPoolSize(t *testing.T) {
 	verifyIntValue(t, vstart, "StreamConnPoolCapacity", 1)
 }
 
+// TestTxPoolSize starts 2 transactions, one in normal pool and one in found rows pool of transaction pool.
+// Changing the pool size to 1, we verify that the pool size is updated and the pool is full when we try to acquire next transaction.
+func TestTxPoolSize(t *testing.T) {
+	vstart := framework.DebugVars()
+
+	verifyIntValue(t, vstart, "TransactionPoolCapacity", 20)
+	verifyIntValue(t, vstart, "FoundRowsPoolCapacity", 20)
+
+	client1 := framework.NewClient()
+	err := client1.Begin( /* found rows pool*/ false)
+	require.NoError(t, err)
+	defer client1.Rollback()
+	verifyIntValue(t, framework.DebugVars(), "TransactionPoolAvailable", framework.FetchInt(vstart, "TransactionPoolAvailable")-1)
+
+	client2 := framework.NewClient()
+	err = client2.Begin( /* found rows pool*/ true)
+	require.NoError(t, err)
+	defer client2.Rollback()
+	verifyIntValue(t, framework.DebugVars(), "FoundRowsPoolAvailable", framework.FetchInt(vstart, "FoundRowsPoolAvailable")-1)
+
+	revert := changeVar(t, "TxPoolSize", "1")
+	defer revert()
+	vend := framework.DebugVars()
+	verifyIntValue(t, vend, "TransactionPoolAvailable", 0)
+	verifyIntValue(t, vend, "TransactionPoolCapacity", 1)
+	verifyIntValue(t, vend, "FoundRowsPoolAvailable", 0)
+	verifyIntValue(t, vend, "FoundRowsPoolCapacity", 1)
+	assert.Equal(t, 1, framework.Server.TxPoolSize())
+
+	client3 := framework.NewClient()
+
+	// tx pool - normal
+	err = client3.Begin( /* found rows pool*/ false)
+	require.ErrorContains(t, err, "connection limit exceeded")
+	compareIntDiff(t, framework.DebugVars(), "Errors/RESOURCE_EXHAUSTED", vstart, 1)
+
+	// tx pool - found rows
+	err = client3.Begin( /* found rows pool*/ true)
+	require.ErrorContains(t, err, "connection limit exceeded")
+	compareIntDiff(t, framework.DebugVars(), "Errors/RESOURCE_EXHAUSTED", vstart, 2)
+}
+
 func TestDisableConsolidator(t *testing.T) {
 	totalConsolidationsTag := "Waits/Histograms/Consolidations/Count"
 	initial := framework.FetchInt(framework.DebugVars(), totalConsolidationsTag)

go/vt/vttablet/endtoend/transaction_test.go

@@ -22,20 +22,16 @@ import (
 	"testing"
 	"time"
 
-	"vitess.io/vitess/go/vt/vttablet/tabletserver/tabletenv/tabletenvtest"
-
-	"google.golang.org/protobuf/proto"
-
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"google.golang.org/protobuf/proto"
 
 	"vitess.io/vitess/go/mysql"
 	"vitess.io/vitess/go/test/utils"
 	querypb "vitess.io/vitess/go/vt/proto/query"
 	topodatapb "vitess.io/vitess/go/vt/proto/topodata"
 	"vitess.io/vitess/go/vt/vttablet/endtoend/framework"
 	"vitess.io/vitess/go/vt/vttablet/tabletserver"
-	"vitess.io/vitess/go/vt/vttablet/tabletserver/tabletenv"
 )
 
 func TestCommit(t *testing.T) {
@@ -202,30 +198,6 @@ func TestAutoCommit(t *testing.T) {
 	}
 }
 
-func TestTxPoolSize(t *testing.T) {
-	tabletenvtest.LoadTabletEnvFlags()
-
-	vstart := framework.DebugVars()
-
-	client1 := framework.NewClient()
-	err := client1.Begin(false)
-	require.NoError(t, err)
-	defer client1.Rollback()
-	verifyIntValue(t, framework.DebugVars(), "TransactionPoolAvailable", tabletenv.NewCurrentConfig().TxPool.Size-1)
-
-	revert := changeVar(t, "TxPoolSize", "1")
-	defer revert()
-	vend := framework.DebugVars()
-	verifyIntValue(t, vend, "TransactionPoolAvailable", 0)
-	verifyIntValue(t, vend, "TransactionPoolCapacity", 1)
-
-	client2 := framework.NewClient()
-	err = client2.Begin(false)
-	require.Error(t, err)
-	require.Contains(t, err.Error(), "connection limit exceeded")
-	compareIntDiff(t, framework.DebugVars(), "Errors/RESOURCE_EXHAUSTED", vstart, 1)
-}
-
 func TestForUpdate(t *testing.T) {
 	for _, mode := range []string{"for update", "lock in share mode"} {
 		client := framework.NewClient()

go/vt/vttablet/tabletserver/tabletserver.go

@@ -2024,7 +2024,11 @@ func (tsv *TabletServer) StreamPoolSize() int {
 
 // SetTxPoolSize changes the tx pool size to the specified value.
 func (tsv *TabletServer) SetTxPoolSize(ctx context.Context, val int) error {
-	return tsv.te.txPool.scp.conns.SetCapacity(ctx, int64(val))
+	// TxPool manages two pools, one for normal connections and one for CLIENT_FOUND_ROWS capability enabled on the connections.
+	if err := tsv.te.txPool.scp.conns.SetCapacity(ctx, int64(val)); err != nil {
+		return err
+	}
+	return tsv.te.txPool.scp.foundRowsPool.SetCapacity(ctx, int64(val))
 }
 
 // TxPoolSize returns the tx pool size.