modify error message when transaction not found in numbered pool

go/pools/numbered.go

@@ -108,7 +108,7 @@ func (nu *Numbered) Get(id int64, purpose string) (val any, err error) {
 		if unreg, ok := nu.recentlyUnregistered.Get(fmt.Sprintf("%v", id)); ok {
 			return nil, fmt.Errorf("ended at %v (%v)", unreg.timeUnregistered.Format("2006-01-02 15:04:05.000 MST"), unreg.reason)
 		}
-		return nil, fmt.Errorf("not found")
+		return nil, fmt.Errorf("not found (potential transaction timeout)")
 	}
 	if nw.inUse {
 		return nil, fmt.Errorf("in use: %s", nw.purpose)

go/pools/numbered_test.go

@@ -45,7 +45,7 @@ func TestNumberedGeneral(t *testing.T) {
 
 	p.Put(id)
 	_, err = p.Get(1, "test2")
-	assert.Contains(t, "not found", err.Error())
+	assert.ErrorContains(t, err, "not found (potential transaction timeout)")
 	p.Unregister(1, "test") // Should not fail
 	p.Unregister(0, "test")
 	// p is now empty

go/vt/vttablet/tabletserver/stateful_connection_pool_test.go

@@ -165,7 +165,7 @@ func TestActivePoolGetConnNonExistentTransaction(t *testing.T) {
 	params := dbconfigs.New(db.ConnParams())
 	pool.Open(params, params, params)
 	_, err := pool.GetAndLock(12345, "for query")
-	require.EqualError(t, err, "not found")
+	require.EqualError(t, err, "not found (potential transaction timeout)")
 }
 
 func TestExecWithAbortedCtx(t *testing.T) {

go/vt/vttablet/tabletserver/tabletserver_test.go

@@ -497,7 +497,7 @@ func TestTabletServerCommiRollbacktFail(t *testing.T) {
 
 	target := querypb.Target{TabletType: topodatapb.TabletType_PRIMARY}
 	_, err := tsv.Commit(ctx, &target, -1)
-	want := "transaction -1: not found"
+	want := "transaction -1: not found (potential transaction timeout)"
 	require.Equal(t, want, err.Error())
 	_, err = tsv.Rollback(ctx, &target, -1)
 	require.Equal(t, want, err.Error())

go/vt/vttablet/tabletserver/tx_engine_test.go

@@ -588,7 +588,7 @@ func TestTxEngineFailReserve(t *testing.T) {
 
 	nonExistingID := int64(42)
 	_, err = te.Reserve(ctx, options, nonExistingID, nil)
-	assert.EqualError(t, err, "transaction 42: not found")
+	assert.EqualError(t, err, "transaction 42: not found (potential transaction timeout)")
 
 	txID, _, _, err := te.Begin(ctx, nil, 0, nil, options)
 	require.NoError(t, err)

go/vt/vttablet/tabletserver/tx_executor_test.go

@@ -78,7 +78,7 @@ func TestTxExecutorPrepareNotInTx(t *testing.T) {
 	defer db.Close()
 	defer tsv.StopService()
 	err := txe.Prepare(0, "aa")
-	require.EqualError(t, err, "transaction 0: not found")
+	require.EqualError(t, err, "transaction 0: not found (potential transaction timeout)")
 }
 
 func TestTxExecutorPreparePoolFail(t *testing.T) {