Add LogRequest variable to config input

edgraph/server.go

@@ -767,7 +767,7 @@ func (s *Server) Query(ctx context.Context, req *api.Request) (*api.Response, er
 
 func (s *Server) doQuery(ctx context.Context, req *api.Request, doAuth AuthMode) (
 	resp *api.Response, rerr error) {
-	if glog.V(3) {
+	if glog.V(3) || atomic.LoadInt32(&x.WorkerConfig.LogRequest) > 0 {
 		glog.Infof("Got a query: %+v", req)
 	}
 	isGraphQL, _ := ctx.Value(IsGraphql).(bool)

graphql/admin/admin.go

@@ -68,7 +68,7 @@ const (
 		schema: String!  @dgraph(pred: "dgraph.graphql.schema")
 
 		"""
-		The GraphQL schema that was generated from the 'schema' field.  
+		The GraphQL schema that was generated from the 'schema' field.
 		This is the schema that is being served by Dgraph at /graphql.
 		"""
 		generatedSchema: String!
@@ -220,10 +220,16 @@ const (
 	input ConfigInput {
 
 		"""
-		Estimated memory the LRU cache can take. Actual usage by the process would be 
+		Estimated memory the LRU cache can take. Actual usage by the process would be
 		more than specified here. (default -1 means no set limit)
 		"""
 		lruMb: Float
+
+		"""
+		True value of logRequest enables logging of all the requests coming to alphas.
+		False value of logRequest disables above.
+		"""
+		logRequest: Boolean
 	}
 
 	type ConfigPayload {

graphql/admin/config.go

@@ -19,15 +19,21 @@ package admin
 import (
 	"context"
 	"encoding/json"
+	"sync/atomic"
 
 	"github.com/dgraph-io/dgraph/graphql/resolve"
 	"github.com/dgraph-io/dgraph/graphql/schema"
 	"github.com/dgraph-io/dgraph/worker"
+	"github.com/dgraph-io/dgraph/x"
 	"github.com/golang/glog"
 )
 
 type configInput struct {
 	LruMB float64
+	// LogRequest is used to update WorkerOptions.LogRequest. true value of LogRequest enables
+	// logging of all requests coming to alphas. LogRequest type has been kept as *bool instead of
+	// bool to avoid updating WorkerOptions.LogRequest when it has default value of false.
+	LogRequest *bool
 }
 
 func resolveConfig(ctx context.Context, m schema.Mutation) (*resolve.Resolved, bool) {
@@ -38,9 +44,19 @@ func resolveConfig(ctx context.Context, m schema.Mutation) (*resolve.Resolved, b
 		return emptyResult(m, err), false
 	}
 
-	err = worker.UpdateLruMb(input.LruMB)
-	if err != nil {
-		return emptyResult(m, err), false
+	if input.LruMB > 0 {
+		if err = worker.UpdateLruMb(input.LruMB); err != nil {
+			return emptyResult(m, err), false
+		}
+	}
+
+	// input.LogRequest will be nil, when it is not specified explicitly in config request.
+	if input.LogRequest != nil {
+		if *input.LogRequest {
+			atomic.StoreInt32(&x.WorkerConfig.LogRequest, 1)
+		} else {
+			atomic.StoreInt32(&x.WorkerConfig.LogRequest, -1)
+		}
 	}
 
 	return &resolve.Resolved{

x/config.go

@@ -84,6 +84,11 @@ type WorkerOptions struct {
 	LudicrousMode bool
 	// BadgerKeyFile is the file containing the key used for encryption. Enterprise only feature.
 	BadgerKeyFile string
+	// LogRequest indicates whether alpha should log all query/mutation requests coming to it.
+	// Ideally LogRequest should be a bool value. But we are reading it using atomics across
+	// queries hence it has been kept as int32. Postive value of LogRequest enables logging of
+	// requests coming to alphas.
+	LogRequest int32
 }
 
 // WorkerConfig stores the global instance of the worker package's options.