diff --git a/go/mysql/mariadb_gtid.go b/go/mysql/mariadb_gtid.go
index b091400d8eb..e40584ab00d 100644
--- a/go/mysql/mariadb_gtid.go
+++ b/go/mysql/mariadb_gtid.go
@@ -59,11 +59,16 @@ func parseMariadbGTID(s string) (GTID, error) {
 
 // parseMariadbGTIDSet is registered as a GTIDSet parser.
 func parseMariadbGTIDSet(s string) (GTIDSet, error) {
-	gtid, err := parseMariadbGTID(s)
-	if err != nil {
-		return nil, err
+	gtidStrings := strings.Split(s, ",")
+	gtidSet := make(MariadbGTIDSet, len(gtidStrings))
+	for i, gtidString := range gtidStrings {
+		gtid, err := parseMariadbGTID(gtidString)
+		if err != nil {
+			return nil, err
+		}
+		gtidSet[i] = gtid.(MariadbGTID)
 	}
-	return gtid.(MariadbGTID), err
+	return gtidSet, nil
 }
 
 // MariadbGTID implements GTID.
@@ -76,6 +81,9 @@ type MariadbGTID struct {
 	Sequence uint64
 }
 
+// MariadbGTIDSet implements GTIDSet
+type MariadbGTIDSet []MariadbGTID
+
 // String implements GTID.String().
 func (gtid MariadbGTID) String() string {
 	return fmt.Sprintf("%d-%d-%d", gtid.Domain, gtid.Server, gtid.Sequence)
@@ -103,49 +111,90 @@ func (gtid MariadbGTID) SequenceNumber() interface{} {
 
 // GTIDSet implements GTID.GTIDSet().
 func (gtid MariadbGTID) GTIDSet() GTIDSet {
-	return gtid
+	return MariadbGTIDSet{gtid}
+}
+
+// String implements GTIDSet.String()
+func (gtidSet MariadbGTIDSet) String() string {
+	s := make([]string, len(gtidSet))
+	for i, gtid := range gtidSet {
+		s[i] = gtid.String()
+	}
+	return strings.Join(s, ",")
+}
+
+// Flavor implements GTIDSet.Flavor()
+func (gtidSet MariadbGTIDSet) Flavor() string {
+	return mariadbFlavorID
 }
 
 // ContainsGTID implements GTIDSet.ContainsGTID().
-func (gtid MariadbGTID) ContainsGTID(other GTID) bool {
+func (gtidSet MariadbGTIDSet) ContainsGTID(other GTID) bool {
 	if other == nil {
 		return true
 	}
 	mdbOther, ok := other.(MariadbGTID)
-	if !ok || gtid.Domain != mdbOther.Domain {
+	if !ok {
 		return false
 	}
-	return gtid.Sequence >= mdbOther.Sequence
+	for _, gtid := range gtidSet {
+		if gtid.Domain != mdbOther.Domain {
+			continue
+		}
+		return gtid.Sequence >= mdbOther.Sequence
+	}
+	return false
 }
 
 // Contains implements GTIDSet.Contains().
-func (gtid MariadbGTID) Contains(other GTIDSet) bool {
+func (gtidSet MariadbGTIDSet) Contains(other GTIDSet) bool {
 	if other == nil {
 		return true
 	}
-	mdbOther, ok := other.(MariadbGTID)
-	if !ok || gtid.Domain != mdbOther.Domain {
+	mdbOther, ok := other.(MariadbGTIDSet)
+	if !ok {
 		return false
 	}
-	return gtid.Sequence >= mdbOther.Sequence
+	for _, gtid := range mdbOther {
+		if !gtidSet.ContainsGTID(gtid) {
+			return false
+		}
+	}
+	return true
 }
 
 // Equal implements GTIDSet.Equal().
-func (gtid MariadbGTID) Equal(other GTIDSet) bool {
-	mdbOther, ok := other.(MariadbGTID)
+func (gtidSet MariadbGTIDSet) Equal(other GTIDSet) bool {
+	mdbOther, ok := other.(MariadbGTIDSet)
 	if !ok {
 		return false
 	}
-	return gtid == mdbOther
+	if len(gtidSet) != len(mdbOther) {
+		return false
+	}
+	for i, gtid := range gtidSet {
+		if gtid != mdbOther[i] {
+			return false
+		}
+	}
+	return true
 }
 
 // AddGTID implements GTIDSet.AddGTID().
-func (gtid MariadbGTID) AddGTID(other GTID) GTIDSet {
+func (gtidSet MariadbGTIDSet) AddGTID(other GTID) GTIDSet {
 	mdbOther, ok := other.(MariadbGTID)
-	if !ok || gtid.Domain != mdbOther.Domain || gtid.Sequence >= mdbOther.Sequence {
-		return gtid
+	if !ok || other == nil {
+		return gtidSet
+	}
+	for i, gtid := range gtidSet {
+		if mdbOther.Domain == gtid.Domain {
+			if mdbOther.Sequence > gtid.Sequence {
+				gtidSet[i] = mdbOther
+			}
+			return gtidSet
+		}
 	}
-	return mdbOther
+	return append(gtidSet, mdbOther)
 }
 
 func init() {
diff --git a/go/mysql/mariadb_gtid_test.go b/go/mysql/mariadb_gtid_test.go
index 10be0a6d3e7..6bd738c9723 100644
--- a/go/mysql/mariadb_gtid_test.go
+++ b/go/mysql/mariadb_gtid_test.go
@@ -87,20 +87,20 @@ func TestParseMariaGTIDInvalidSequence(t *testing.T) {
 }
 
 func TestParseMariaGTIDSet(t *testing.T) {
-	input := "12-34-5678"
-	want := MariadbGTID{Domain: 12, Server: 34, Sequence: 5678}
+	input := "12-34-5678,11-22-3333"
+	want := MariadbGTIDSet{MariadbGTID{Domain: 12, Server: 34, Sequence: 5678}, MariadbGTID{Domain: 11, Server: 22, Sequence: 3333}}
 
 	got, err := parseMariadbGTIDSet(input)
 	if err != nil {
 		t.Errorf("%v", err)
 	}
-	if got.(MariadbGTID) != want {
+	if !got.Equal(want) {
 		t.Errorf("parseMariadbGTIDSet(%#v) = %#v, want %#v", input, got, want)
 	}
 }
 
 func TestParseInvalidMariaGTIDSet(t *testing.T) {
-	input := "12-34-56d78"
+	input := "12-34-5678,11-22-33e33"
 	want := "invalid MariaDB GTID Sequence number"
 
 	_, err := parseMariadbGTIDSet(input)
@@ -165,17 +165,17 @@ func TestMariaGTIDSequenceNumber(t *testing.T) {
 
 func TestMariaGTIDGTIDSet(t *testing.T) {
 	input := MariadbGTID{Domain: 12, Server: 345, Sequence: 6789}
-	want := GTIDSet(input)
+	want := MariadbGTIDSet{input}
 
 	got := input.GTIDSet()
-	if got != want {
+	if !got.Equal(want) {
 		t.Errorf("%#v.GTIDSet() = %#v, want %#v", input, got, want)
 	}
 }
 
-func TestMariaGTIDContainsLess(t *testing.T) {
-	input1 := MariadbGTID{Domain: 5, Server: 4727, Sequence: 300}
-	input2 := MariadbGTID{Domain: 5, Server: 4727, Sequence: 700}
+func TestMariaGTIDSetContainsLess(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 5, Server: 4727, Sequence: 300}}
+	input2 := MariadbGTIDSet{MariadbGTID{Domain: 5, Server: 4727, Sequence: 700}}
 	want := false
 
 	if got := input1.Contains(input2); got != want {
@@ -183,9 +183,9 @@ func TestMariaGTIDContainsLess(t *testing.T) {
 	}
 }
 
-func TestMariaGTIDContainsGreater(t *testing.T) {
-	input1 := MariadbGTID{Domain: 5, Server: 4727, Sequence: 9000}
-	input2 := MariadbGTID{Domain: 5, Server: 4727, Sequence: 100}
+func TestMariaGTIDSetContainsGreater(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 5, Server: 4727, Sequence: 9000}}
+	input2 := MariadbGTIDSet{MariadbGTID{Domain: 5, Server: 4727, Sequence: 100}}
 	want := true
 
 	if got := input1.Contains(input2); got != want {
@@ -193,9 +193,9 @@ func TestMariaGTIDContainsGreater(t *testing.T) {
 	}
 }
 
-func TestMariaGTIDContainsEqual(t *testing.T) {
-	input1 := MariadbGTID{Domain: 5, Server: 4727, Sequence: 1234}
-	input2 := MariadbGTID{Domain: 5, Server: 4727, Sequence: 1234}
+func TestMariaGTIDSetContainsEqual(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 5, Server: 4727, Sequence: 1234}}
+	input2 := MariadbGTIDSet{MariadbGTID{Domain: 5, Server: 4727, Sequence: 1234}}
 	want := true
 
 	if got := input1.Contains(input2); got != want {
@@ -203,8 +203,58 @@ func TestMariaGTIDContainsEqual(t *testing.T) {
 	}
 }
 
-func TestMariaGTIDContainsNil(t *testing.T) {
-	input1 := MariadbGTID{Domain: 1, Server: 2, Sequence: 123}
+func TestMariaGTIDSetMultipleContainsLess(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 4, Server: 1, Sequence: 123}, MariadbGTID{Domain: 5, Server: 5, Sequence: 24601}}
+	input2 := MariadbGTIDSet{MariadbGTID{Domain: 4, Server: 1, Sequence: 124}}
+	want := false
+
+	if got := input1.Contains(input2); got != want {
+		t.Errorf("%#v.Contains(%#v) = %v, want %v", input1, input2, got, want)
+	}
+}
+
+func TestMariaGTIDSetMultipleContainsGreater(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 4, Server: 1, Sequence: 123}, MariadbGTID{Domain: 5, Server: 5, Sequence: 24601}}
+	input2 := MariadbGTIDSet{MariadbGTID{Domain: 4, Server: 1, Sequence: 122}}
+	want := true
+
+	if got := input1.Contains(input2); got != want {
+		t.Errorf("%#v.Contains(%#v) = %v, want %v", input1, input2, got, want)
+	}
+}
+
+func TestMariaGTIDSetMultipleContainsMultipleGreater(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 4, Server: 1, Sequence: 123}, MariadbGTID{Domain: 5, Server: 5, Sequence: 24601}}
+	input2 := MariadbGTIDSet{MariadbGTID{Domain: 4, Server: 1, Sequence: 122}, MariadbGTID{Domain: 5, Server: 4, Sequence: 1999}}
+	want := true
+
+	if got := input1.Contains(input2); got != want {
+		t.Errorf("%#v.Contains(%#v) = %v, want %v", input1, input2, got, want)
+	}
+}
+
+func TestMariaGTIDSetMultipleContainsOneLess(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 4, Server: 1, Sequence: 123}, MariadbGTID{Domain: 5, Server: 5, Sequence: 24601}}
+	input2 := MariadbGTIDSet{MariadbGTID{Domain: 4, Server: 1, Sequence: 122}, MariadbGTID{Domain: 5, Server: 4, Sequence: 24602}}
+	want := false
+
+	if got := input1.Contains(input2); got != want {
+		t.Errorf("%#v.Contains(%#v) = %v, want %v", input1, input2, got, want)
+	}
+}
+
+func TestMariaGTIDSetSingleContainsMultiple(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 4, Server: 1, Sequence: 123}}
+	input2 := MariadbGTIDSet{MariadbGTID{Domain: 4, Server: 1, Sequence: 122}, MariadbGTID{Domain: 5, Server: 4, Sequence: 24602}}
+	want := false
+
+	if got := input1.Contains(input2); got != want {
+		t.Errorf("%#v.Contains(%#v) = %v, want %v", input1, input2, got, want)
+	}
+}
+
+func TestMariaGTIDSetContainsNil(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 1, Server: 2, Sequence: 123}}
 	input2 := GTIDSet(nil)
 	want := true
 
@@ -213,8 +263,8 @@ func TestMariaGTIDContainsNil(t *testing.T) {
 	}
 }
 
-func TestMariaGTIDContainsWrongType(t *testing.T) {
-	input1 := MariadbGTID{Domain: 5, Server: 4727, Sequence: 1234}
+func TestMariaGTIDSetContainsWrongType(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 5, Server: 4727, Sequence: 1234}}
 	input2 := fakeGTID{}
 	want := false
 
@@ -223,9 +273,9 @@ func TestMariaGTIDContainsWrongType(t *testing.T) {
 	}
 }
 
-func TestMariaGTIDContainsDifferentDomain(t *testing.T) {
-	input1 := MariadbGTID{Domain: 3, Server: 4727, Sequence: 1235}
-	input2 := MariadbGTID{Domain: 5, Server: 4727, Sequence: 1234}
+func TestMariaGTIDSetContainsDifferentDomain(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 4727, Sequence: 1235}}
+	input2 := MariadbGTIDSet{MariadbGTID{Domain: 5, Server: 4727, Sequence: 1234}}
 	want := false
 
 	if got := input1.Contains(input2); got != want {
@@ -233,9 +283,9 @@ func TestMariaGTIDContainsDifferentDomain(t *testing.T) {
 	}
 }
 
-func TestMariaGTIDContainsDifferentServer(t *testing.T) {
-	input1 := MariadbGTID{Domain: 3, Server: 4727, Sequence: 1235}
-	input2 := MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}
+func TestMariaGTIDSetContainsDifferentServer(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 4727, Sequence: 1235}}
+	input2 := MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}
 	want := true
 
 	if got := input1.Contains(input2); got != want {
@@ -243,8 +293,8 @@ func TestMariaGTIDContainsDifferentServer(t *testing.T) {
 	}
 }
 
-func TestMariaGTIDContainsGTIDLess(t *testing.T) {
-	input1 := MariadbGTID{Domain: 5, Server: 4727, Sequence: 300}
+func TestMariaGTIDSetContainsGTIDLess(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 5, Server: 4727, Sequence: 300}}
 	input2 := MariadbGTID{Domain: 5, Server: 4727, Sequence: 700}
 	want := false
 
@@ -253,8 +303,8 @@ func TestMariaGTIDContainsGTIDLess(t *testing.T) {
 	}
 }
 
-func TestMariaGTIDContainsGTIDGreater(t *testing.T) {
-	input1 := MariadbGTID{Domain: 5, Server: 4727, Sequence: 9000}
+func TestMariaGTIDSetContainsGTIDGreater(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 5, Server: 4727, Sequence: 9000}}
 	input2 := MariadbGTID{Domain: 5, Server: 4727, Sequence: 100}
 	want := true
 
@@ -263,8 +313,8 @@ func TestMariaGTIDContainsGTIDGreater(t *testing.T) {
 	}
 }
 
-func TestMariaGTIDContainsGTIDEqual(t *testing.T) {
-	input1 := MariadbGTID{Domain: 5, Server: 4727, Sequence: 1234}
+func TestMariaGTIDSetContainsGTIDEqual(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 5, Server: 4727, Sequence: 1234}}
 	input2 := MariadbGTID{Domain: 5, Server: 4727, Sequence: 1234}
 	want := true
 
@@ -273,8 +323,8 @@ func TestMariaGTIDContainsGTIDEqual(t *testing.T) {
 	}
 }
 
-func TestMariaGTIDContainsGTIDNil(t *testing.T) {
-	input1 := MariadbGTID{Domain: 1, Server: 2, Sequence: 123}
+func TestMariaGTIDSetContainsGTIDNil(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 1, Server: 2, Sequence: 123}}
 	input2 := GTID(nil)
 	want := true
 
@@ -283,8 +333,8 @@ func TestMariaGTIDContainsGTIDNil(t *testing.T) {
 	}
 }
 
-func TestMariaGTIDContainsGTIDWrongType(t *testing.T) {
-	input1 := MariadbGTID{Domain: 5, Server: 4727, Sequence: 1234}
+func TestMariaGTIDSetContainsGTIDWrongType(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 5, Server: 4727, Sequence: 1234}}
 	input2 := fakeGTID{}
 	want := false
 
@@ -293,8 +343,8 @@ func TestMariaGTIDContainsGTIDWrongType(t *testing.T) {
 	}
 }
 
-func TestMariaGTIDContainsGTIDDifferentDomain(t *testing.T) {
-	input1 := MariadbGTID{Domain: 3, Server: 4727, Sequence: 1235}
+func TestMariaGTIDSetContainsGTIDDifferentDomain(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 4727, Sequence: 1235}}
 	input2 := MariadbGTID{Domain: 5, Server: 4727, Sequence: 1234}
 	want := false
 
@@ -303,8 +353,8 @@ func TestMariaGTIDContainsGTIDDifferentDomain(t *testing.T) {
 	}
 }
 
-func TestMariaGTIDContainsGTIDDifferentServer(t *testing.T) {
-	input1 := MariadbGTID{Domain: 3, Server: 4727, Sequence: 1235}
+func TestMariaGTIDSetContainsGTIDDifferentServer(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 4727, Sequence: 1235}}
 	input2 := MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}
 	want := true
 
@@ -313,9 +363,9 @@ func TestMariaGTIDContainsGTIDDifferentServer(t *testing.T) {
 	}
 }
 
-func TestMariaGTIDEqual(t *testing.T) {
-	input1 := MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}
-	input2 := MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}
+func TestMariaGTIDSetEqual(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}
+	input2 := MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}
 	want := true
 
 	if got := input1.Equal(input2); got != want {
@@ -323,9 +373,9 @@ func TestMariaGTIDEqual(t *testing.T) {
 	}
 }
 
-func TestMariaGTIDNotEqual(t *testing.T) {
-	input1 := MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}
-	input2 := MariadbGTID{Domain: 3, Server: 4555, Sequence: 1234}
+func TestMariaGTIDSetNotEqual(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}
+	input2 := MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 4555, Sequence: 1234}}
 	want := false
 
 	if got := input1.Equal(input2); got != want {
@@ -333,8 +383,8 @@ func TestMariaGTIDNotEqual(t *testing.T) {
 	}
 }
 
-func TestMariaGTIDEqualWrongType(t *testing.T) {
-	input1 := MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}
+func TestMariaGTIDSetEqualWrongType(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}
 	input2 := fakeGTID{}
 	want := false
 
@@ -343,8 +393,8 @@ func TestMariaGTIDEqualWrongType(t *testing.T) {
 	}
 }
 
-func TestMariaGTIDEqualNil(t *testing.T) {
-	input1 := MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}
+func TestMariaGTIDSetEqualNil(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}
 	input2 := GTIDSet(nil)
 	want := false
 
@@ -353,72 +403,72 @@ func TestMariaGTIDEqualNil(t *testing.T) {
 	}
 }
 
-func TestMariaGTIDAddGTIDEqual(t *testing.T) {
-	input1 := MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}
+func TestMariaGTIDSetAddGTIDEqual(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}
 	input2 := MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}
-	want := MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}
+	want := input1
 
-	if got := input1.AddGTID(input2); got != want {
+	if got := input1.AddGTID(input2); !got.Equal(want) {
 		t.Errorf("%#v.AddGTID(%#v) = %v, want %v", input1, input2, got, want)
 	}
 }
 
-func TestMariaGTIDAddGTIDGreater(t *testing.T) {
-	input1 := MariadbGTID{Domain: 3, Server: 5555, Sequence: 5234}
+func TestMariaGTIDSetAddGTIDGreater(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 5234}}
 	input2 := MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}
-	want := MariadbGTID{Domain: 3, Server: 5555, Sequence: 5234}
+	want := input1
 
-	if got := input1.AddGTID(input2); got != want {
+	if got := input1.AddGTID(input2); !got.Equal(want) {
 		t.Errorf("%#v.AddGTID(%#v) = %v, want %v", input1, input2, got, want)
 	}
 }
 
-func TestMariaGTIDAddGTIDLess(t *testing.T) {
-	input1 := MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}
+func TestMariaGTIDSetAddGTIDLess(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}
 	input2 := MariadbGTID{Domain: 3, Server: 5555, Sequence: 5234}
-	want := MariadbGTID{Domain: 3, Server: 5555, Sequence: 5234}
+	want := MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 5234}}
 
-	if got := input1.AddGTID(input2); got != want {
+	if got := input1.AddGTID(input2); !got.Equal(want) {
 		t.Errorf("%#v.AddGTID(%#v) = %v, want %v", input1, input2, got, want)
 	}
 }
 
-func TestMariaGTIDAddGTIDWrongType(t *testing.T) {
-	input1 := MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}
+func TestMariaGTIDSetAddGTIDWrongType(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}
 	input2 := fakeGTID{}
 	want := input1
 
-	if got := input1.AddGTID(input2); got != want {
+	if got := input1.AddGTID(input2); !got.Equal(want) {
 		t.Errorf("%#v.AddGTID(%#v) = %v, want %v", input1, input2, got, want)
 	}
 }
 
-func TestMariaGTIDAddGTIDNil(t *testing.T) {
-	input1 := MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}
+func TestMariaGTIDSetAddGTIDNil(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}
 	input2 := GTID(nil)
 	want := input1
 
-	if got := input1.AddGTID(input2); got != want {
+	if got := input1.AddGTID(input2); !got.Equal(want) {
 		t.Errorf("%#v.AddGTID(%#v) = %v, want %v", input1, input2, got, want)
 	}
 }
 
-func TestMariaGTIDAddGTIDDifferentServer(t *testing.T) {
-	input1 := MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}
+func TestMariaGTIDSetAddGTIDDifferentServer(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}
 	input2 := MariadbGTID{Domain: 3, Server: 4444, Sequence: 5234}
-	want := MariadbGTID{Domain: 3, Server: 4444, Sequence: 5234}
+	want := MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 4444, Sequence: 5234}}
 
-	if got := input1.AddGTID(input2); got != want {
+	if got := input1.AddGTID(input2); !got.Equal(want) {
 		t.Errorf("%#v.AddGTID(%#v) = %v, want %v", input1, input2, got, want)
 	}
 }
 
-func TestMariaGTIDAddGTIDDifferentDomain(t *testing.T) {
-	input1 := MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}
+func TestMariaGTIDSetAddGTIDDifferentDomain(t *testing.T) {
+	input1 := MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}
 	input2 := MariadbGTID{Domain: 5, Server: 5555, Sequence: 5234}
-	want := MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}
+	want := MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}, MariadbGTID{Domain: 5, Server: 5555, Sequence: 5234}}
 
-	if got := input1.AddGTID(input2); got != want {
+	if got := input1.AddGTID(input2); !got.Equal(want) {
 		t.Errorf("%#v.AddGTID(%#v) = %v, want %v", input1, input2, got, want)
 	}
 }
diff --git a/go/mysql/replication_position_test.go b/go/mysql/replication_position_test.go
index 051aded50a6..76dce397d00 100644
--- a/go/mysql/replication_position_test.go
+++ b/go/mysql/replication_position_test.go
@@ -23,8 +23,8 @@ import (
 )
 
 func TestPositionEqual(t *testing.T) {
-	input1 := Position{GTIDSet: MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}
-	input2 := Position{GTIDSet: MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}
+	input1 := Position{GTIDSet: MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}}
+	input2 := Position{GTIDSet: MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}}
 	want := true
 
 	if got := input1.Equal(input2); got != want {
@@ -33,8 +33,8 @@ func TestPositionEqual(t *testing.T) {
 }
 
 func TestPositionNotEqual(t *testing.T) {
-	input1 := Position{GTIDSet: MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}
-	input2 := Position{GTIDSet: MariadbGTID{Domain: 3, Server: 5555, Sequence: 12345}}
+	input1 := Position{GTIDSet: MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}}
+	input2 := Position{GTIDSet: MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 12345}}}
 	want := false
 
 	if got := input1.Equal(input2); got != want {
@@ -43,7 +43,7 @@ func TestPositionNotEqual(t *testing.T) {
 }
 
 func TestPositionEqualZero(t *testing.T) {
-	input1 := Position{GTIDSet: MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}
+	input1 := Position{GTIDSet: MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}}
 	input2 := Position{}
 	want := false
 
@@ -63,8 +63,8 @@ func TestPositionZeroEqualZero(t *testing.T) {
 }
 
 func TestPositionAtLeastLess(t *testing.T) {
-	input1 := Position{GTIDSet: MariadbGTID{Domain: 3, Server: 5555, Sequence: 1233}}
-	input2 := Position{GTIDSet: MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}
+	input1 := Position{GTIDSet: MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1233}}}
+	input2 := Position{GTIDSet: MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}}
 	want := false
 
 	if got := input1.AtLeast(input2); got != want {
@@ -73,8 +73,8 @@ func TestPositionAtLeastLess(t *testing.T) {
 }
 
 func TestPositionAtLeastEqual(t *testing.T) {
-	input1 := Position{GTIDSet: MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}
-	input2 := Position{GTIDSet: MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}
+	input1 := Position{GTIDSet: MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}}
+	input2 := Position{GTIDSet: MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}}
 	want := true
 
 	if got := input1.AtLeast(input2); got != want {
@@ -83,8 +83,8 @@ func TestPositionAtLeastEqual(t *testing.T) {
 }
 
 func TestPositionAtLeastGreater(t *testing.T) {
-	input1 := Position{GTIDSet: MariadbGTID{Domain: 3, Server: 5555, Sequence: 1235}}
-	input2 := Position{GTIDSet: MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}
+	input1 := Position{GTIDSet: MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1235}}}
+	input2 := Position{GTIDSet: MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}}
 	want := true
 
 	if got := input1.AtLeast(input2); got != want {
@@ -93,8 +93,8 @@ func TestPositionAtLeastGreater(t *testing.T) {
 }
 
 func TestPositionAtLeastDifferentServer(t *testing.T) {
-	input1 := Position{GTIDSet: MariadbGTID{Domain: 3, Server: 5555, Sequence: 1235}}
-	input2 := Position{GTIDSet: MariadbGTID{Domain: 3, Server: 4444, Sequence: 1234}}
+	input1 := Position{GTIDSet: MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1235}}}
+	input2 := Position{GTIDSet: MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 4444, Sequence: 1234}}}
 	want := true
 
 	if got := input1.AtLeast(input2); got != want {
@@ -103,8 +103,8 @@ func TestPositionAtLeastDifferentServer(t *testing.T) {
 }
 
 func TestPositionAtLeastDifferentDomain(t *testing.T) {
-	input1 := Position{GTIDSet: MariadbGTID{Domain: 3, Server: 5555, Sequence: 1235}}
-	input2 := Position{GTIDSet: MariadbGTID{Domain: 4, Server: 5555, Sequence: 1234}}
+	input1 := Position{GTIDSet: MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1235}}}
+	input2 := Position{GTIDSet: MariadbGTIDSet{MariadbGTID{Domain: 4, Server: 5555, Sequence: 1234}}}
 	want := false
 
 	if got := input1.AtLeast(input2); got != want {
@@ -114,7 +114,7 @@ func TestPositionAtLeastDifferentDomain(t *testing.T) {
 
 func TestPositionZeroAtLeast(t *testing.T) {
 	input1 := Position{}
-	input2 := Position{GTIDSet: MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}
+	input2 := Position{GTIDSet: MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}}
 	want := false
 
 	if got := input1.AtLeast(input2); got != want {
@@ -123,7 +123,7 @@ func TestPositionZeroAtLeast(t *testing.T) {
 }
 
 func TestPositionAtLeastZero(t *testing.T) {
-	input1 := Position{GTIDSet: MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}
+	input1 := Position{GTIDSet: MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}}
 	input2 := Position{}
 	want := true
 
@@ -143,7 +143,7 @@ func TestPositionZeroAtLeastZero(t *testing.T) {
 }
 
 func TestPositionString(t *testing.T) {
-	input := Position{GTIDSet: MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}
+	input := Position{GTIDSet: MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}}
 	want := "3-5555-1234"
 
 	if got := input.String(); got != want {
@@ -170,7 +170,7 @@ func TestPositionIsZero(t *testing.T) {
 }
 
 func TestPositionIsNotZero(t *testing.T) {
-	input := Position{GTIDSet: MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}
+	input := Position{GTIDSet: MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}}
 	want := false
 
 	if got := input.IsZero(); got != want {
@@ -179,9 +179,9 @@ func TestPositionIsNotZero(t *testing.T) {
 }
 
 func TestPositionAppend(t *testing.T) {
-	input1 := Position{GTIDSet: MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}
+	input1 := Position{GTIDSet: MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}}
 	input2 := MariadbGTID{Domain: 3, Server: 5555, Sequence: 1235}
-	want := Position{GTIDSet: MariadbGTID{Domain: 3, Server: 5555, Sequence: 1235}}
+	want := Position{GTIDSet: MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1235}}}
 
 	if got := AppendGTID(input1, input2); !got.Equal(want) {
 		t.Errorf("AppendGTID(%#v, %#v) = %#v, want %#v", input1, input2, got, want)
@@ -189,9 +189,9 @@ func TestPositionAppend(t *testing.T) {
 }
 
 func TestPositionAppendNil(t *testing.T) {
-	input1 := Position{GTIDSet: MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}
+	input1 := Position{GTIDSet: MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}}
 	input2 := GTID(nil)
-	want := Position{GTIDSet: MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}
+	want := Position{GTIDSet: MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}}
 
 	if got := AppendGTID(input1, input2); !got.Equal(want) {
 		t.Errorf("AppendGTID(%#v, %#v) = %#v, want %#v", input1, input2, got, want)
@@ -201,7 +201,7 @@ func TestPositionAppendNil(t *testing.T) {
 func TestPositionAppendToZero(t *testing.T) {
 	input1 := Position{}
 	input2 := MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}
-	want := Position{GTIDSet: MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}
+	want := Position{GTIDSet: MariadbGTIDSet{MariadbGTID{Domain: 3, Server: 5555, Sequence: 1234}}}
 
 	if got := AppendGTID(input1, input2); !got.Equal(want) {
 		t.Errorf("AppendGTID(%#v, %#v) = %#v, want %#v", input1, input2, got, want)
diff --git a/go/vt/binlog/binlog_streamer_rbr_test.go b/go/vt/binlog/binlog_streamer_rbr_test.go
index 9a8e1a77925..d30255d4f52 100644
--- a/go/vt/binlog/binlog_streamer_rbr_test.go
+++ b/go/vt/binlog/binlog_streamer_rbr_test.go
@@ -237,10 +237,12 @@ func TestStreamerParseRBREvents(t *testing.T) {
 			eventToken: &querypb.EventToken{
 				Timestamp: 1407805592,
 				Position: mysql.EncodePosition(mysql.Position{
-					GTIDSet: mysql.MariadbGTID{
-						Domain:   0,
-						Server:   62344,
-						Sequence: 0x0d,
+					GTIDSet: mysql.MariadbGTIDSet{
+						mysql.MariadbGTID{
+							Domain:   0,
+							Server:   62344,
+							Sequence: 0x0d,
+						},
 					},
 				}),
 			},
@@ -477,10 +479,12 @@ func TestStreamerParseRBRNameEscapes(t *testing.T) {
 			eventToken: &querypb.EventToken{
 				Timestamp: 1407805592,
 				Position: mysql.EncodePosition(mysql.Position{
-					GTIDSet: mysql.MariadbGTID{
-						Domain:   0,
-						Server:   62344,
-						Sequence: 0x0d,
+					GTIDSet: mysql.MariadbGTIDSet{
+						mysql.MariadbGTID{
+							Domain:   0,
+							Server:   62344,
+							Sequence: 0x0d,
+						},
 					},
 				}),
 			},
diff --git a/go/vt/binlog/binlog_streamer_test.go b/go/vt/binlog/binlog_streamer_test.go
index fc3fcb0f856..576e7b5620c 100644
--- a/go/vt/binlog/binlog_streamer_test.go
+++ b/go/vt/binlog/binlog_streamer_test.go
@@ -103,10 +103,12 @@ func TestStreamerParseEventsXID(t *testing.T) {
 			EventToken: &querypb.EventToken{
 				Timestamp: 1407805592,
 				Position: mysql.EncodePosition(mysql.Position{
-					GTIDSet: mysql.MariadbGTID{
-						Domain:   0,
-						Server:   62344,
-						Sequence: 0x0d,
+					GTIDSet: mysql.MariadbGTIDSet{
+						mysql.MariadbGTID{
+							Domain:   0,
+							Server:   62344,
+							Sequence: 0x0d,
+						},
 					},
 				}),
 			},
@@ -157,10 +159,12 @@ func TestStreamerParseEventsCommit(t *testing.T) {
 			EventToken: &querypb.EventToken{
 				Timestamp: 1407805592,
 				Position: mysql.EncodePosition(mysql.Position{
-					GTIDSet: mysql.MariadbGTID{
-						Domain:   0,
-						Server:   62344,
-						Sequence: 0x0d,
+					GTIDSet: mysql.MariadbGTIDSet{
+						mysql.MariadbGTID{
+							Domain:   0,
+							Server:   62344,
+							Sequence: 0x0d,
+						},
 					},
 				}),
 			},
@@ -504,10 +508,12 @@ func TestStreamerParseEventsRollback(t *testing.T) {
 			EventToken: &querypb.EventToken{
 				Timestamp: 1407805592,
 				Position: mysql.EncodePosition(mysql.Position{
-					GTIDSet: mysql.MariadbGTID{
-						Domain:   0,
-						Server:   62344,
-						Sequence: 0x0d,
+					GTIDSet: mysql.MariadbGTIDSet{
+						mysql.MariadbGTID{
+							Domain:   0,
+							Server:   62344,
+							Sequence: 0x0d,
+						},
 					},
 				}),
 			},
@@ -520,10 +526,12 @@ func TestStreamerParseEventsRollback(t *testing.T) {
 			EventToken: &querypb.EventToken{
 				Timestamp: 1407805592,
 				Position: mysql.EncodePosition(mysql.Position{
-					GTIDSet: mysql.MariadbGTID{
-						Domain:   0,
-						Server:   62344,
-						Sequence: 0x0d,
+					GTIDSet: mysql.MariadbGTIDSet{
+						mysql.MariadbGTID{
+							Domain:   0,
+							Server:   62344,
+							Sequence: 0x0d,
+						},
 					},
 				}),
 			},
@@ -568,10 +576,12 @@ func TestStreamerParseEventsDMLWithoutBegin(t *testing.T) {
 			EventToken: &querypb.EventToken{
 				Timestamp: 1407805592,
 				Position: mysql.EncodePosition(mysql.Position{
-					GTIDSet: mysql.MariadbGTID{
-						Domain:   0,
-						Server:   62344,
-						Sequence: 0x0d,
+					GTIDSet: mysql.MariadbGTIDSet{
+						mysql.MariadbGTID{
+							Domain:   0,
+							Server:   62344,
+							Sequence: 0x0d,
+						},
 					},
 				}),
 			},
@@ -581,10 +591,12 @@ func TestStreamerParseEventsDMLWithoutBegin(t *testing.T) {
 			EventToken: &querypb.EventToken{
 				Timestamp: 1407805592,
 				Position: mysql.EncodePosition(mysql.Position{
-					GTIDSet: mysql.MariadbGTID{
-						Domain:   0,
-						Server:   62344,
-						Sequence: 0x0d,
+					GTIDSet: mysql.MariadbGTIDSet{
+						mysql.MariadbGTID{
+							Domain:   0,
+							Server:   62344,
+							Sequence: 0x0d,
+						},
 					},
 				}),
 			},
@@ -632,10 +644,12 @@ func TestStreamerParseEventsBeginWithoutCommit(t *testing.T) {
 			EventToken: &querypb.EventToken{
 				Timestamp: 1407805592,
 				Position: mysql.EncodePosition(mysql.Position{
-					GTIDSet: mysql.MariadbGTID{
-						Domain:   0,
-						Server:   62344,
-						Sequence: 0x0d,
+					GTIDSet: mysql.MariadbGTIDSet{
+						mysql.MariadbGTID{
+							Domain:   0,
+							Server:   62344,
+							Sequence: 0x0d,
+						},
 					},
 				}),
 			},
@@ -645,10 +659,12 @@ func TestStreamerParseEventsBeginWithoutCommit(t *testing.T) {
 			EventToken: &querypb.EventToken{
 				Timestamp: 1407805592,
 				Position: mysql.EncodePosition(mysql.Position{
-					GTIDSet: mysql.MariadbGTID{
-						Domain:   0,
-						Server:   62344,
-						Sequence: 0x0d,
+					GTIDSet: mysql.MariadbGTIDSet{
+						mysql.MariadbGTID{
+							Domain:   0,
+							Server:   62344,
+							Sequence: 0x0d,
+						},
 					},
 				}),
 			},
@@ -698,10 +714,12 @@ func TestStreamerParseEventsSetInsertID(t *testing.T) {
 			EventToken: &querypb.EventToken{
 				Timestamp: 1407805592,
 				Position: mysql.EncodePosition(mysql.Position{
-					GTIDSet: mysql.MariadbGTID{
-						Domain:   0,
-						Server:   62344,
-						Sequence: 0x0d,
+					GTIDSet: mysql.MariadbGTIDSet{
+						mysql.MariadbGTID{
+							Domain:   0,
+							Server:   62344,
+							Sequence: 0x0d,
+						},
 					},
 				}),
 			},
@@ -788,10 +806,12 @@ func TestStreamerParseEventsOtherDB(t *testing.T) {
 			EventToken: &querypb.EventToken{
 				Timestamp: 1407805592,
 				Position: mysql.EncodePosition(mysql.Position{
-					GTIDSet: mysql.MariadbGTID{
-						Domain:   0,
-						Server:   62344,
-						Sequence: 0x0d,
+					GTIDSet: mysql.MariadbGTIDSet{
+						mysql.MariadbGTID{
+							Domain:   0,
+							Server:   62344,
+							Sequence: 0x0d,
+						},
 					},
 				}),
 			},
@@ -842,10 +862,12 @@ func TestStreamerParseEventsOtherDBBegin(t *testing.T) {
 			EventToken: &querypb.EventToken{
 				Timestamp: 1407805592,
 				Position: mysql.EncodePosition(mysql.Position{
-					GTIDSet: mysql.MariadbGTID{
-						Domain:   0,
-						Server:   62344,
-						Sequence: 0x0d,
+					GTIDSet: mysql.MariadbGTIDSet{
+						mysql.MariadbGTID{
+							Domain:   0,
+							Server:   62344,
+							Sequence: 0x0d,
+						},
 					},
 				}),
 			},
@@ -938,10 +960,12 @@ func TestStreamerParseEventsMariadbBeginGTID(t *testing.T) {
 			EventToken: &querypb.EventToken{
 				Timestamp: 1409892744,
 				Position: mysql.EncodePosition(mysql.Position{
-					GTIDSet: mysql.MariadbGTID{
-						Domain:   0,
-						Server:   62344,
-						Sequence: 10,
+					GTIDSet: mysql.MariadbGTIDSet{
+						mysql.MariadbGTID{
+							Domain:   0,
+							Server:   62344,
+							Sequence: 10,
+						},
 					},
 				}),
 			},
@@ -989,10 +1013,12 @@ func TestStreamerParseEventsMariadbStandaloneGTID(t *testing.T) {
 			EventToken: &querypb.EventToken{
 				Timestamp: 1409892744,
 				Position: mysql.EncodePosition(mysql.Position{
-					GTIDSet: mysql.MariadbGTID{
-						Domain:   0,
-						Server:   62344,
-						Sequence: 9,
+					GTIDSet: mysql.MariadbGTIDSet{
+						mysql.MariadbGTID{
+							Domain:   0,
+							Server:   62344,
+							Sequence: 9,
+						},
 					},
 				}),
 			},
diff --git a/go/vt/worker/legacy_split_clone_test.go b/go/vt/worker/legacy_split_clone_test.go
index 09bd1329c4a..f1bd3cad9f7 100644
--- a/go/vt/worker/legacy_split_clone_test.go
+++ b/go/vt/worker/legacy_split_clone_test.go
@@ -171,7 +171,7 @@ func (tc *legacySplitCloneTestCase) setUp(v3 bool) {
 			},
 		}
 		sourceRdonly.FakeMysqlDaemon.CurrentMasterPosition = mysql.Position{
-			GTIDSet: mysql.MariadbGTID{Domain: 12, Server: 34, Sequence: 5678},
+			GTIDSet: mysql.MariadbGTIDSet{mysql.MariadbGTID{Domain: 12, Server: 34, Sequence: 5678}},
 		}
 		sourceRdonly.FakeMysqlDaemon.ExpectedExecuteSuperQueryList = []string{
 			"STOP SLAVE",
diff --git a/go/vt/worker/split_clone_test.go b/go/vt/worker/split_clone_test.go
index 395555b32ae..36647f9494f 100644
--- a/go/vt/worker/split_clone_test.go
+++ b/go/vt/worker/split_clone_test.go
@@ -213,7 +213,7 @@ func (tc *splitCloneTestCase) setUpWithConcurrency(v3 bool, concurrency, writeQu
 			},
 		}
 		sourceRdonly.FakeMysqlDaemon.CurrentMasterPosition = mysql.Position{
-			GTIDSet: mysql.MariadbGTID{Domain: 12, Server: 34, Sequence: 5678},
+			GTIDSet: mysql.MariadbGTIDSet{mysql.MariadbGTID{Domain: 12, Server: 34, Sequence: 5678}},
 		}
 		sourceRdonly.FakeMysqlDaemon.ExpectedExecuteSuperQueryList = []string{
 			"STOP SLAVE",
diff --git a/go/vt/worker/vertical_split_clone_test.go b/go/vt/worker/vertical_split_clone_test.go
index 0d2ac0953ad..ad351c3363b 100644
--- a/go/vt/worker/vertical_split_clone_test.go
+++ b/go/vt/worker/vertical_split_clone_test.go
@@ -132,7 +132,7 @@ func TestVerticalSplitClone(t *testing.T) {
 		},
 	}
 	sourceRdonly.FakeMysqlDaemon.CurrentMasterPosition = mysql.Position{
-		GTIDSet: mysql.MariadbGTID{Domain: 12, Server: 34, Sequence: 5678},
+		GTIDSet: mysql.MariadbGTIDSet{mysql.MariadbGTID{Domain: 12, Server: 34, Sequence: 5678}},
 	}
 	sourceRdonly.FakeMysqlDaemon.ExpectedExecuteSuperQueryList = []string{
 		"STOP SLAVE",
diff --git a/go/vt/wrangler/testlib/backup_test.go b/go/vt/wrangler/testlib/backup_test.go
index e359fba6916..a9abb4497d8 100644
--- a/go/vt/wrangler/testlib/backup_test.go
+++ b/go/vt/wrangler/testlib/backup_test.go
@@ -98,10 +98,12 @@ func TestBackupRestore(t *testing.T) {
 	sourceTablet.FakeMysqlDaemon.ReadOnly = true
 	sourceTablet.FakeMysqlDaemon.Replicating = true
 	sourceTablet.FakeMysqlDaemon.CurrentMasterPosition = mysql.Position{
-		GTIDSet: mysql.MariadbGTID{
-			Domain:   2,
-			Server:   123,
-			Sequence: 457,
+		GTIDSet: mysql.MariadbGTIDSet{
+			mysql.MariadbGTID{
+				Domain:   2,
+				Server:   123,
+				Sequence: 457,
+			},
 		},
 	}
 	sourceTablet.FakeMysqlDaemon.ExpectedExecuteSuperQueryList = []string{
@@ -138,10 +140,12 @@ func TestBackupRestore(t *testing.T) {
 	destTablet.FakeMysqlDaemon.ReadOnly = true
 	destTablet.FakeMysqlDaemon.Replicating = true
 	destTablet.FakeMysqlDaemon.CurrentMasterPosition = mysql.Position{
-		GTIDSet: mysql.MariadbGTID{
-			Domain:   2,
-			Server:   123,
-			Sequence: 457,
+		GTIDSet: mysql.MariadbGTIDSet{
+			mysql.MariadbGTID{
+				Domain:   2,
+				Server:   123,
+				Sequence: 457,
+			},
 		},
 	}
 	destTablet.FakeMysqlDaemon.ExpectedExecuteSuperQueryList = []string{
diff --git a/go/vt/wrangler/testlib/emergency_reparent_shard_test.go b/go/vt/wrangler/testlib/emergency_reparent_shard_test.go
index acb1f1599e6..0df00ad3d58 100644
--- a/go/vt/wrangler/testlib/emergency_reparent_shard_test.go
+++ b/go/vt/wrangler/testlib/emergency_reparent_shard_test.go
@@ -49,10 +49,12 @@ func TestEmergencyReparentShard(t *testing.T) {
 	newMaster.FakeMysqlDaemon.ReadOnly = true
 	newMaster.FakeMysqlDaemon.Replicating = true
 	newMaster.FakeMysqlDaemon.CurrentMasterPosition = mysql.Position{
-		GTIDSet: mysql.MariadbGTID{
-			Domain:   2,
-			Server:   123,
-			Sequence: 456,
+		GTIDSet: mysql.MariadbGTIDSet{
+			mysql.MariadbGTID{
+				Domain:   2,
+				Server:   123,
+				Sequence: 456,
+			},
 		},
 	}
 	newMaster.FakeMysqlDaemon.ExpectedExecuteSuperQueryList = []string{
@@ -62,10 +64,12 @@ func TestEmergencyReparentShard(t *testing.T) {
 		"SUBINSERT INTO _vt.reparent_journal (time_created_ns, action_name, master_alias, replication_position) VALUES",
 	}
 	newMaster.FakeMysqlDaemon.PromoteSlaveResult = mysql.Position{
-		GTIDSet: mysql.MariadbGTID{
-			Domain:   2,
-			Server:   123,
-			Sequence: 456,
+		GTIDSet: mysql.MariadbGTIDSet{
+			mysql.MariadbGTID{
+				Domain:   2,
+				Server:   123,
+				Sequence: 456,
+			},
 		},
 	}
 	newMaster.StartActionLoop(t, wr)
@@ -80,10 +84,12 @@ func TestEmergencyReparentShard(t *testing.T) {
 	goodSlave1.FakeMysqlDaemon.ReadOnly = true
 	goodSlave1.FakeMysqlDaemon.Replicating = true
 	goodSlave1.FakeMysqlDaemon.CurrentMasterPosition = mysql.Position{
-		GTIDSet: mysql.MariadbGTID{
-			Domain:   2,
-			Server:   123,
-			Sequence: 455,
+		GTIDSet: mysql.MariadbGTIDSet{
+			mysql.MariadbGTID{
+				Domain:   2,
+				Server:   123,
+				Sequence: 455,
+			},
 		},
 	}
 	goodSlave1.FakeMysqlDaemon.SetMasterInput = topoproto.MysqlAddr(newMaster.Tablet)
@@ -99,10 +105,12 @@ func TestEmergencyReparentShard(t *testing.T) {
 	goodSlave2.FakeMysqlDaemon.ReadOnly = true
 	goodSlave2.FakeMysqlDaemon.Replicating = false
 	goodSlave2.FakeMysqlDaemon.CurrentMasterPosition = mysql.Position{
-		GTIDSet: mysql.MariadbGTID{
-			Domain:   2,
-			Server:   123,
-			Sequence: 454,
+		GTIDSet: mysql.MariadbGTIDSet{
+			mysql.MariadbGTID{
+				Domain:   2,
+				Server:   123,
+				Sequence: 454,
+			},
 		},
 	}
 	goodSlave2.FakeMysqlDaemon.SetMasterInput = topoproto.MysqlAddr(newMaster.Tablet)
@@ -165,10 +173,12 @@ func TestEmergencyReparentShardMasterElectNotBest(t *testing.T) {
 	// new master
 	newMaster.FakeMysqlDaemon.Replicating = true
 	newMaster.FakeMysqlDaemon.CurrentMasterPosition = mysql.Position{
-		GTIDSet: mysql.MariadbGTID{
-			Domain:   2,
-			Server:   123,
-			Sequence: 456,
+		GTIDSet: mysql.MariadbGTIDSet{
+			mysql.MariadbGTID{
+				Domain:   2,
+				Server:   123,
+				Sequence: 456,
+			},
 		},
 	}
 	newMaster.FakeMysqlDaemon.ExpectedExecuteSuperQueryList = []string{
@@ -184,10 +194,12 @@ func TestEmergencyReparentShardMasterElectNotBest(t *testing.T) {
 	// more advanced slave
 	moreAdvancedSlave.FakeMysqlDaemon.Replicating = true
 	moreAdvancedSlave.FakeMysqlDaemon.CurrentMasterPosition = mysql.Position{
-		GTIDSet: mysql.MariadbGTID{
-			Domain:   2,
-			Server:   123,
-			Sequence: 457,
+		GTIDSet: mysql.MariadbGTIDSet{
+			mysql.MariadbGTID{
+				Domain:   2,
+				Server:   123,
+				Sequence: 457,
+			},
 		},
 	}
 	moreAdvancedSlave.FakeMysqlDaemon.ExpectedExecuteSuperQueryList = []string{
diff --git a/go/vt/wrangler/testlib/init_shard_master_test.go b/go/vt/wrangler/testlib/init_shard_master_test.go
index b1ca1cfe488..faf6d9069c0 100644
--- a/go/vt/wrangler/testlib/init_shard_master_test.go
+++ b/go/vt/wrangler/testlib/init_shard_master_test.go
@@ -58,10 +58,12 @@ func TestInitMasterShard(t *testing.T) {
 	// Master: set a plausible ReplicationPosition to return,
 	// and expect to add entry in _vt.reparent_journal
 	master.FakeMysqlDaemon.CurrentMasterPosition = mysql.Position{
-		GTIDSet: mysql.MariadbGTID{
-			Domain:   5,
-			Server:   456,
-			Sequence: 890,
+		GTIDSet: mysql.MariadbGTIDSet{
+			mysql.MariadbGTID{
+				Domain:   5,
+				Server:   456,
+				Sequence: 890,
+			},
 		},
 	}
 	master.FakeMysqlDaemon.ReadOnly = true
@@ -186,10 +188,12 @@ func TestInitMasterShardOneSlaveFails(t *testing.T) {
 	// Master: set a plausible ReplicationPosition to return,
 	// and expect to add entry in _vt.reparent_journal
 	master.FakeMysqlDaemon.CurrentMasterPosition = mysql.Position{
-		GTIDSet: mysql.MariadbGTID{
-			Domain:   5,
-			Server:   456,
-			Sequence: 890,
+		GTIDSet: mysql.MariadbGTIDSet{
+			mysql.MariadbGTID{
+				Domain:   5,
+				Server:   456,
+				Sequence: 890,
+			},
 		},
 	}
 	master.FakeMysqlDaemon.ReadOnly = true
diff --git a/go/vt/wrangler/testlib/migrate_served_from_test.go b/go/vt/wrangler/testlib/migrate_served_from_test.go
index bd51f1fdf0c..6194e2150ed 100644
--- a/go/vt/wrangler/testlib/migrate_served_from_test.go
+++ b/go/vt/wrangler/testlib/migrate_served_from_test.go
@@ -81,10 +81,12 @@ func TestMigrateServedFrom(t *testing.T) {
 	// sourceMaster will see the refresh, and has to respond to it
 	// also will be asked about its replication position.
 	sourceMaster.FakeMysqlDaemon.CurrentMasterPosition = mysql.Position{
-		GTIDSet: mysql.MariadbGTID{
-			Domain:   5,
-			Server:   456,
-			Sequence: 892,
+		GTIDSet: mysql.MariadbGTIDSet{
+			mysql.MariadbGTID{
+				Domain:   5,
+				Server:   456,
+				Sequence: 892,
+			},
 		},
 	}
 	sourceMaster.StartActionLoop(t, wr)
diff --git a/go/vt/wrangler/testlib/migrate_served_types_test.go b/go/vt/wrangler/testlib/migrate_served_types_test.go
index eb8a872eb68..28ae7789ffe 100644
--- a/go/vt/wrangler/testlib/migrate_served_types_test.go
+++ b/go/vt/wrangler/testlib/migrate_served_types_test.go
@@ -116,10 +116,12 @@ func TestMigrateServedTypes(t *testing.T) {
 	// sourceMaster will see the refresh, and has to respond to it
 	// also will be asked about its replication position.
 	sourceMaster.FakeMysqlDaemon.CurrentMasterPosition = mysql.Position{
-		GTIDSet: mysql.MariadbGTID{
-			Domain:   5,
-			Server:   456,
-			Sequence: 892,
+		GTIDSet: mysql.MariadbGTIDSet{
+			mysql.MariadbGTID{
+				Domain:   5,
+				Server:   456,
+				Sequence: 892,
+			},
 		},
 	}
 	sourceMaster.StartActionLoop(t, wr)
diff --git a/go/vt/wrangler/testlib/planned_reparent_shard_test.go b/go/vt/wrangler/testlib/planned_reparent_shard_test.go
index 3bf5a31cc03..24edf62800d 100644
--- a/go/vt/wrangler/testlib/planned_reparent_shard_test.go
+++ b/go/vt/wrangler/testlib/planned_reparent_shard_test.go
@@ -46,17 +46,21 @@ func TestPlannedReparentShardNoMasterProvided(t *testing.T) {
 	newMaster.FakeMysqlDaemon.ReadOnly = true
 	newMaster.FakeMysqlDaemon.Replicating = true
 	newMaster.FakeMysqlDaemon.WaitMasterPosition = mysql.Position{
-		GTIDSet: mysql.MariadbGTID{
-			Domain:   7,
-			Server:   123,
-			Sequence: 990,
+		GTIDSet: mysql.MariadbGTIDSet{
+			mysql.MariadbGTID{
+				Domain:   7,
+				Server:   123,
+				Sequence: 990,
+			},
 		},
 	}
 	newMaster.FakeMysqlDaemon.PromoteSlaveResult = mysql.Position{
-		GTIDSet: mysql.MariadbGTID{
-			Domain:   7,
-			Server:   456,
-			Sequence: 991,
+		GTIDSet: mysql.MariadbGTIDSet{
+			mysql.MariadbGTID{
+				Domain:   7,
+				Server:   456,
+				Sequence: 991,
+			},
 		},
 	}
 	newMaster.FakeMysqlDaemon.ExpectedExecuteSuperQueryList = []string{
@@ -148,17 +152,21 @@ func TestPlannedReparentShard(t *testing.T) {
 	newMaster.FakeMysqlDaemon.ReadOnly = true
 	newMaster.FakeMysqlDaemon.Replicating = true
 	newMaster.FakeMysqlDaemon.WaitMasterPosition = mysql.Position{
-		GTIDSet: mysql.MariadbGTID{
-			Domain:   7,
-			Server:   123,
-			Sequence: 990,
+		GTIDSet: mysql.MariadbGTIDSet{
+			mysql.MariadbGTID{
+				Domain:   7,
+				Server:   123,
+				Sequence: 990,
+			},
 		},
 	}
 	newMaster.FakeMysqlDaemon.PromoteSlaveResult = mysql.Position{
-		GTIDSet: mysql.MariadbGTID{
-			Domain:   7,
-			Server:   456,
-			Sequence: 991,
+		GTIDSet: mysql.MariadbGTIDSet{
+			mysql.MariadbGTID{
+				Domain:   7,
+				Server:   456,
+				Sequence: 991,
+			},
 		},
 	}
 	newMaster.FakeMysqlDaemon.ExpectedExecuteSuperQueryList = []string{
diff --git a/go/vt/wrangler/testlib/reparent_utils_test.go b/go/vt/wrangler/testlib/reparent_utils_test.go
index 18e97a95b71..f78b8b3734f 100644
--- a/go/vt/wrangler/testlib/reparent_utils_test.go
+++ b/go/vt/wrangler/testlib/reparent_utils_test.go
@@ -54,10 +54,12 @@ func TestShardReplicationStatuses(t *testing.T) {
 
 	// master action loop (to initialize host and port)
 	master.FakeMysqlDaemon.CurrentMasterPosition = mysql.Position{
-		GTIDSet: mysql.MariadbGTID{
-			Domain:   5,
-			Server:   456,
-			Sequence: 892,
+		GTIDSet: mysql.MariadbGTIDSet{
+			mysql.MariadbGTID{
+				Domain:   5,
+				Server:   456,
+				Sequence: 892,
+			},
 		},
 	}
 	master.StartActionLoop(t, wr)
@@ -65,10 +67,12 @@ func TestShardReplicationStatuses(t *testing.T) {
 
 	// slave loop
 	slave.FakeMysqlDaemon.CurrentMasterPosition = mysql.Position{
-		GTIDSet: mysql.MariadbGTID{
-			Domain:   5,
-			Server:   456,
-			Sequence: 890,
+		GTIDSet: mysql.MariadbGTIDSet{
+			mysql.MariadbGTID{
+				Domain:   5,
+				Server:   456,
+				Sequence: 890,
+			},
 		},
 	}
 	slave.FakeMysqlDaemon.CurrentMasterHost = topoproto.MysqlHostname(master.Tablet)