add rate limit on more rpcs

rpc/pool.go

@@ -2,6 +2,10 @@ package rpc
 
 import (
 	"context"
+	"fmt"
+	"github.com/prometheus/client_golang/prometheus"
+	"golang.org/x/time/rate"
+	"reflect"
 
 	"github.com/pkg/errors"
 
@@ -27,6 +31,9 @@ import (
 type PublicPoolService struct {
 	hmy     *hmy.Harmony
 	version Version
+
+	// TEMP SOLUTION to rpc node spamming issue
+	limiterPendingTransactions *rate.Limiter
 }
 
 // NewPublicPoolAPI creates a new API for the RPC interface
@@ -34,11 +41,28 @@ func NewPublicPoolAPI(hmy *hmy.Harmony, version Version) rpc.API {
 	return rpc.API{
 		Namespace: version.Namespace(),
 		Version:   APIVersion,
-		Service:   &PublicPoolService{hmy, version},
+		Service:   &PublicPoolService{hmy, version, rate.NewLimiter(5, 10)},
 		Public:    true,
 	}
 }
 
+func (s *PublicPoolService) wait(limiter *rate.Limiter, ctx context.Context) error {
+	if limiter != nil {
+		deadlineCtx, cancel := context.WithTimeout(ctx, DefaultRateLimiterWaitTimeout)
+		defer cancel()
+		if !limiter.Allow() {
+			strLimit := fmt.Sprintf("%d", int64(limiter.Limit()))
+			name := reflect.TypeOf(limiter).Elem().Name()
+			rpcRateLimitCounterVec.With(prometheus.Labels{
+				name: strLimit,
+			}).Inc()
+		}
+
+		return limiter.Wait(deadlineCtx)
+	}
+	return nil
+}
+
 // SendRawTransaction will add the signed transaction to the transaction pool.
 // The sender is responsible for signing the transaction and using the correct nonce.
 func (s *PublicPoolService) SendRawTransaction(
@@ -190,6 +214,12 @@ func (s *PublicPoolService) PendingTransactions(
 	timer := DoMetricRPCRequest(PendingTransactions)
 	defer DoRPCRequestDuration(PendingTransactions, timer)
 
+	err := s.wait(s.limiterPendingTransactions, ctx)
+	if err != nil {
+		DoMetricRPCQueryInfo(PendingTransactions, FailedNumber)
+		return nil, err
+	}
+
 	// Fetch all pending transactions (stx & plain tx)
 	pending, err := s.hmy.GetPoolTransactions()
 	if err != nil {

rpc/staking.go

@@ -37,6 +37,7 @@ type PublicStakingService struct {
 	// TEMP SOLUTION to rpc node spamming issue
 	limiterGetAllValidatorInformation  *rate.Limiter
 	limiterGetAllDelegationInformation *rate.Limiter
+	limiterGetDelegationsByValidator   *rate.Limiter
 }
 
 // NewPublicStakingAPI creates a new API for the RPC interface
@@ -51,6 +52,7 @@ func NewPublicStakingAPI(hmy *hmy.Harmony, version Version) rpc.API {
 			validatorInfoCache:                 viCache,
 			limiterGetAllValidatorInformation:  rate.NewLimiter(1, 3),
 			limiterGetAllDelegationInformation: rate.NewLimiter(1, 3),
+			limiterGetDelegationsByValidator:   rate.NewLimiter(5, 20),
 		},
 		Public: true,
 	}
@@ -542,7 +544,7 @@ func (s *PublicStakingService) GetAllDelegationInformation(
 	// Fetch all delegations
 	validators := make([][]StructuredResponse, validatorsNum)
 	for i := start; i < start+validatorsNum; i++ {
-		validators[i-start], err = s.GetDelegationsByValidator(ctx, addresses[i].String())
+		validators[i-start], err = s.getDelegationByValidatorHelper(addresses[i].String())
 		if err != nil {
 			DoMetricRPCQueryInfo(GetAllDelegationInformation, FailedNumber)
 			return nil, err
@@ -687,6 +689,15 @@ func (s *PublicStakingService) GetDelegationsByValidator(
 		return nil, ErrNotBeaconShard
 	}
 
+	err := s.wait(s.limiterGetDelegationsByValidator, ctx)
+	if err != nil {
+		DoMetricRPCQueryInfo(GetDelegationsByValidator, FailedNumber)
+		return nil, err
+	}
+	return s.getDelegationByValidatorHelper(address)
+}
+
+func (s *PublicStakingService) getDelegationByValidatorHelper(address string) ([]StructuredResponse, error) {
 	// Fetch delegations
 	validatorAddress, err := internal_common.ParseAddr(address)
 	if err != nil {