instruments

inside.go

@@ -3,6 +3,7 @@ package nebula
 import (
 	"net/netip"
 
+	"github.com/rcrowley/go-metrics"
 	"github.com/sirupsen/logrus"
 	"github.com/slackhq/nebula/firewall"
 	"github.com/slackhq/nebula/header"
@@ -145,9 +146,12 @@ func (f *Interface) consumeInsidePackets(packets [][]byte, sizes []int, count in
 
 	// Send all accumulated packets in one batch
 	if len(*batchPackets) > 0 {
+		batchSize := len(*batchPackets)
+		metrics.GetOrRegisterHistogram("batch.udp_write_size", nil, metrics.NewUniformSample(1024)).Update(int64(batchSize))
+
 		n, err := f.writers[q].WriteMulti(*batchPackets, *batchAddrs)
 		if err != nil {
-			f.l.WithError(err).WithField("sent", n).WithField("total", len(*batchPackets)).Error("Failed to send batch")
+			f.l.WithError(err).WithField("sent", n).WithField("total", batchSize).Error("Failed to send batch")
 		}
 	}
 }

interface.go

@@ -347,6 +347,8 @@ func (f *Interface) listenInBatch(reader io.ReadWriteCloser, batchReader BatchRe
 
 	conntrackCache := firewall.NewConntrackCacheTicker(f.conntrackCacheTimeout)
 
+	tunBatchHist := metrics.GetOrRegisterHistogram("batch.tun_read_size", nil, metrics.NewUniformSample(1024))
+
 	for {
 		n, err := batchReader.BatchRead(bufs, sizes)
 		if err != nil {
@@ -359,6 +361,8 @@ func (f *Interface) listenInBatch(reader io.ReadWriteCloser, batchReader BatchRe
 			os.Exit(2)
 		}
 
+		tunBatchHist.Update(int64(n))
+
 		// Process all packets in the batch at once
 		f.consumeInsidePackets(bufs, sizes, n, outs, i, conntrackCache.Get(f.l), &batchPackets, &batchAddrs)
 	}

overlay/tun_linux.go

@@ -128,6 +128,7 @@ func (w *wgDeviceWrapper) Close() error {
 
 // BatchRead implements batching for multiqueue readers
 func (w *wgDeviceWrapper) BatchRead(bufs [][]byte, sizes []int) (int, error) {
+	// The zero here is offset.
 	return w.dev.Read(bufs, sizes, 0)
 }
 

udp/udp_linux.go

@@ -151,6 +151,8 @@ func (u *StdConn) ListenOut(r EncReader) {
 		read = u.ReadSingle
 	}
 
+	udpBatchHist := metrics.GetOrRegisterHistogram("batch.udp_read_size", nil, metrics.NewUniformSample(1024))
+
 	for {
 		n, err := read(msgs)
 		if err != nil {
@@ -158,6 +160,8 @@ func (u *StdConn) ListenOut(r EncReader) {
 			return
 		}
 
+		udpBatchHist.Update(int64(n))
+
 		for i := 0; i < n; i++ {
 			// Its ok to skip the ok check here, the slicing is the only error that can occur and it will panic
 			if u.isV4 {