Fix(GraphQL): Fix Execution Trace for Add and Update Mutations (#7656) (#7658)

* Remove unused function

* Add tracing for existence query execution

* Fix tests

(cherry picked from commit ba8f5da)

Author: vmrajas

graphql/resolve/extensions_test.go

@@ -163,8 +163,8 @@ func TestMutationsPropagateExtensions(t *testing.T) {
 	require.True(t, resp.Extensions.Tracing.Execution.Resolvers[0].StartOffset > 0)
 	require.True(t, resp.Extensions.Tracing.Execution.Resolvers[0].Duration > 0)
 
-	require.Len(t, resp.Extensions.Tracing.Execution.Resolvers[0].Dgraph, 2)
-	labels := []string{"mutation", "query"}
+	require.Len(t, resp.Extensions.Tracing.Execution.Resolvers[0].Dgraph, 3)
+	labels := []string{"preMutationQuery", "mutation", "query"}
 	for i, dgraphTrace := range resp.Extensions.Tracing.Execution.Resolvers[0].Dgraph {
 		require.Equal(t, dgraphTrace.Label, labels[i])
 		require.True(t, dgraphTrace.StartOffset > 0)
@@ -221,8 +221,8 @@ func TestMultipleMutationsPropagateExtensionsCorrectly(t *testing.T) {
 		require.True(t, resolver.StartOffset > 0)
 		require.True(t, resolver.Duration > 0)
 
-		require.Len(t, resolver.Dgraph, 2)
-		labels := []string{"mutation", "query"}
+		require.Len(t, resolver.Dgraph, 3)
+		labels := []string{"preMutationQuery", "mutation", "query"}
 		for j, dgraphTrace := range resolver.Dgraph {
 			require.Equal(t, dgraphTrace.Label, labels[j])
 			require.True(t, dgraphTrace.StartOffset > 0)

graphql/resolve/mutation.go

@@ -229,16 +229,18 @@ func (mr *dgraphResolver) rewriteAndExecute(
 		}
 	}()
 
+	dgraphPreMutationQueryDuration := &schema.LabeledOffsetDuration{Label: "preMutationQuery"}
 	dgraphMutationDuration := &schema.LabeledOffsetDuration{Label: "mutation"}
-	dgraphQueryDuration := &schema.LabeledOffsetDuration{Label: "query"}
+	dgraphPostMutationQueryDuration := &schema.LabeledOffsetDuration{Label: "query"}
 	ext := &schema.Extensions{
 		Tracing: &schema.Trace{
 			Execution: &schema.ExecutionTrace{
 				Resolvers: []*schema.ResolverTrace{
 					{
 						Dgraph: []*schema.LabeledOffsetDuration{
+							dgraphPreMutationQueryDuration,
 							dgraphMutationDuration,
-							dgraphQueryDuration,
+							dgraphPostMutationQueryDuration,
 						},
 					},
 				},
@@ -275,12 +277,17 @@ func (mr *dgraphResolver) rewriteAndExecute(
 	// Don't execute the query in those cases.
 	// The query will also be empty in case this is not an Add or an Update Mutation.
 	if req.Query != "" {
+		// Executing and processing existence queries
+		queryTimer := newtimer(ctx, &dgraphPreMutationQueryDuration.OffsetDuration)
+		queryTimer.Start()
 		mutResp, err = mr.executor.Execute(ctx, req)
-	}
-	if err != nil {
-		gqlErr := schema.GQLWrapLocationf(
-			err, mutation.Location(), "mutation %s failed", mutation.Name())
-		return emptyResult(gqlErr), resolverFailed
+		queryTimer.Stop()
+		if err != nil {
+			gqlErr := schema.GQLWrapLocationf(
+				err, mutation.Location(), "mutation %s failed", mutation.Name())
+			return emptyResult(gqlErr), resolverFailed
+		}
+		ext.TouchedUids += mutResp.GetMetrics().GetNumUids()[touchedUidsKey]
 	}
 
 	// Parse the result of query.
@@ -405,7 +412,7 @@ func (mr *dgraphResolver) rewriteAndExecute(
 	}
 	commit = true
 
-	queryTimer := newtimer(ctx, &dgraphQueryDuration.OffsetDuration)
+	queryTimer := newtimer(ctx, &dgraphPostMutationQueryDuration.OffsetDuration)
 	queryTimer.Start()
 	qryResp, err := mr.executor.Execute(ctx, &dgoapi.Request{Query: dgraph.AsString(dgQuery),
 		ReadOnly: true})