From 9bf9843ff6b5bbb50189a2c21e15ef5d22f85259 Mon Sep 17 00:00:00 2001
From: Cory Schwartz <cory@protocol.ai>
Date: Wed, 20 Apr 2022 19:48:41 -0700
Subject: [PATCH] add metrics

---
 cmd/lotus-gateway/main.go |  2 +-
 gateway/node.go           |  8 ++++----
 metrics/metrics.go        | 11 +++++++++++
 3 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/cmd/lotus-gateway/main.go b/cmd/lotus-gateway/main.go
index 7e4bc22d0..87dea40d2 100644
--- a/cmd/lotus-gateway/main.go
+++ b/cmd/lotus-gateway/main.go
@@ -149,7 +149,7 @@ var runCmd = &cli.Command{
 
 		// Register all metric views
 		if err := view.Register(
-			metrics.ChainNodeViews...,
+			metrics.GatewayNodeViews...,
 		); err != nil {
 			log.Fatalf("Cannot register the view: %v", err)
 		}
diff --git a/gateway/node.go b/gateway/node.go
index e157645d4..dfeaea237 100644
--- a/gateway/node.go
+++ b/gateway/node.go
@@ -6,6 +6,7 @@ import (
 	"time"
 
 	"github.com/ipfs/go-cid"
+	"go.opencensus.io/stats"
 	"golang.org/x/time/rate"
 	"golang.org/x/xerrors"
 
@@ -22,6 +23,7 @@ import (
 	"github.com/filecoin-project/lotus/lib/sigs"
 	_ "github.com/filecoin-project/lotus/lib/sigs/bls"
 	_ "github.com/filecoin-project/lotus/lib/sigs/secp"
+	"github.com/filecoin-project/lotus/metrics"
 	"github.com/filecoin-project/lotus/node/impl/full"
 )
 
@@ -165,12 +167,10 @@ func (gw *Node) checkTimestamp(at time.Time) error {
 func (gw *Node) limit(ctx context.Context, tokens int) error {
 	ctx2, cancel := context.WithTimeout(ctx, gw.rateLimitTimeout)
 	defer cancel()
-	if !gw.rateLimiter.AllowN(time.Now(), tokens) {
-		return fmt.Errorf("server busy")
-	}
 	err := gw.rateLimiter.WaitN(ctx2, tokens)
 	if err != nil {
-		return fmt.Errorf("server busy, cannot complete before timeout %w", err)
+		stats.Record(ctx, metrics.RateLimitCount.M(1))
+		return fmt.Errorf("server busy. %w", err)
 	}
 	return nil
 }
diff --git a/metrics/metrics.go b/metrics/metrics.go
index 2bbba88d3..8a4c3aa31 100644
--- a/metrics/metrics.go
+++ b/metrics/metrics.go
@@ -167,6 +167,9 @@ var (
 	RcmgrBlockSvcPeer   = stats.Int64("rcmgr/block_svc", "Number of blocked blocked streams attached to a service for a specific peer", stats.UnitDimensionless)
 	RcmgrAllowMem       = stats.Int64("rcmgr/allow_mem", "Number of allowed memory reservations", stats.UnitDimensionless)
 	RcmgrBlockMem       = stats.Int64("rcmgr/block_mem", "Number of blocked memory reservations", stats.UnitDimensionless)
+
+	// gateway rate limit
+	RateLimitCount = stats.Int64("ratelimit/limited", "rate limited connections", stats.UnitDimensionless)
 )
 
 var (
@@ -599,6 +602,10 @@ var (
 		Measure:     RcmgrBlockMem,
 		Aggregation: view.Count(),
 	}
+	RateLimitedView = &view.View{
+		Measure:     RateLimitCount,
+		Aggregation: view.Count(),
+	}
 )
 
 // DefaultViews is an array of OpenCensus views for metric gathering purposes
@@ -711,6 +718,10 @@ var MinerNodeViews = append([]*view.View{
 	DagStorePRSeekForwardBytesView,
 }, DefaultViews...)
 
+var GatewayNodeViews = append([]*view.View{
+	RateLimitedView,
+}, ChainNodeViews...)
+
 // SinceInMilliseconds returns the duration of time since the provide time as a float64.
 func SinceInMilliseconds(startTime time.Time) float64 {
 	return float64(time.Since(startTime).Nanoseconds()) / 1e6