From b89e0786091a683049a62c7eac83588557934fe7 Mon Sep 17 00:00:00 2001
From: Kanishka <kanishkatn@gmail.com>
Date: Mon, 9 Sep 2024 18:57:43 +0530
Subject: [PATCH] Add l1 metrics (#1678)

Co-authored-by: Kirill <paltsev.kir@gmail.com>
---
 l1/eth_subscriber.go | 17 +++++++++++++++--
 l1/event_listener.go | 10 ++++++++++
 node/metrics.go      |  9 +++++++++
 3 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/l1/eth_subscriber.go b/l1/eth_subscriber.go
index 38e7d377db..6ddb213b1e 100644
--- a/l1/eth_subscriber.go
+++ b/l1/eth_subscriber.go
@@ -20,6 +20,7 @@ type EthSubscriber struct {
 	ethClient *ethclient.Client
 	client    *rpc.Client
 	filterer  *contract.StarknetFilterer
+	listener  EventListener
 }
 
 var _ Subscriber = (*EthSubscriber)(nil)
@@ -42,6 +43,7 @@ func NewEthSubscriber(ethClientAddress string, coreContractAddress common.Addres
 		ethClient: ethClient,
 		client:    client,
 		filterer:  filterer,
+		listener:  SelectiveListener{},
 	}, nil
 }
 
@@ -50,14 +52,25 @@ func (s *EthSubscriber) WatchLogStateUpdate(ctx context.Context, sink chan<- *co
 }
 
 func (s *EthSubscriber) ChainID(ctx context.Context) (*big.Int, error) {
-	return s.ethClient.ChainID(ctx)
+	reqTimer := time.Now()
+	chainID, err := s.ethClient.ChainID(ctx)
+	if err != nil {
+		return nil, fmt.Errorf("get chain ID: %w", err)
+	}
+	s.listener.OnL1Call("eth_chainId", time.Since(reqTimer))
+
+	return chainID, nil
 }
 
 func (s *EthSubscriber) FinalisedHeight(ctx context.Context) (uint64, error) {
+	const method = "eth_getBlockByNumber"
+	reqTimer := time.Now()
+
 	var raw json.RawMessage
-	if err := s.client.CallContext(ctx, &raw, "eth_getBlockByNumber", "finalized", false); err != nil { //nolint:misspell
+	if err := s.client.CallContext(ctx, &raw, method, "finalized", false); err != nil { //nolint:misspell
 		return 0, fmt.Errorf("get finalised Ethereum block: %w", err)
 	}
+	s.listener.OnL1Call(method, time.Since(reqTimer))
 
 	var head *types.Header
 	if err := json.Unmarshal(raw, &head); err != nil {
diff --git a/l1/event_listener.go b/l1/event_listener.go
index f5e9a10a32..077fde4cb1 100644
--- a/l1/event_listener.go
+++ b/l1/event_listener.go
@@ -1,15 +1,19 @@
 package l1
 
 import (
+	"time"
+
 	"github.com/NethermindEth/juno/core"
 )
 
 type EventListener interface {
 	OnNewL1Head(head *core.L1Head)
+	OnL1Call(method string, took time.Duration)
 }
 
 type SelectiveListener struct {
 	OnNewL1HeadCb func(head *core.L1Head)
+	OnL1CallCb    func(method string, took time.Duration)
 }
 
 func (l SelectiveListener) OnNewL1Head(head *core.L1Head) {
@@ -17,3 +21,9 @@ func (l SelectiveListener) OnNewL1Head(head *core.L1Head) {
 		l.OnNewL1HeadCb(head)
 	}
 }
+
+func (l SelectiveListener) OnL1Call(method string, took time.Duration) {
+	if l.OnL1CallCb != nil {
+		l.OnL1CallCb(method, took)
+	}
+}
diff --git a/node/metrics.go b/node/metrics.go
index a10ae75a3b..9ac489b5fe 100644
--- a/node/metrics.go
+++ b/node/metrics.go
@@ -226,11 +226,20 @@ func makeL1Metrics() l1.EventListener {
 		Name:      "height",
 	})
 	prometheus.MustRegister(l1Height)
+	requestLatencies := prometheus.NewHistogramVec(prometheus.HistogramOpts{
+		Namespace: "l1",
+		Subsystem: "client",
+		Name:      "request_latency",
+	}, []string{"method"})
+	prometheus.MustRegister(requestLatencies)
 
 	return l1.SelectiveListener{
 		OnNewL1HeadCb: func(head *core.L1Head) {
 			l1Height.Set(float64(head.BlockNumber))
 		},
+		OnL1CallCb: func(method string, took time.Duration) {
+			requestLatencies.WithLabelValues(method).Observe(took.Seconds())
+		},
 	}
 }