Consolidate getMemoryStats (#1122)

* Consolidate getMemoryStats

* Avoid divide-by-0

pkg/routing/localrouter.go

@@ -2,6 +2,7 @@ package routing
 
 import (
 	"context"
+	"runtime"
 	"sync"
 	"time"
 
@@ -171,6 +172,7 @@ func (r *LocalRouter) Start() error {
 		return nil
 	}
 	go r.statsWorker()
+	go r.memStatsWorker()
 	// on local routers, Start doesn't do anything, websocket connections initiate the connections
 	go r.rtcMessageWorker()
 	return nil
@@ -201,6 +203,24 @@ func (r *LocalRouter) statsWorker() {
 	}
 }
 
+func (r *LocalRouter) memStatsWorker() {
+	ticker := time.NewTicker(time.Second * 30)
+	defer ticker.Stop()
+
+	for {
+		<-ticker.C
+
+		var m runtime.MemStats
+		runtime.ReadMemStats(&m)
+		logger.Infow("memstats",
+			"mallocs", m.Mallocs, "frees", m.Frees, "m-f", m.Mallocs-m.Frees,
+			"hinuse", m.HeapInuse, "halloc", m.HeapAlloc, "frag", m.HeapInuse-m.HeapAlloc,
+		)
+
+		runtime.GC()
+	}
+}
+
 func (r *LocalRouter) rtcMessageWorker() {
 	// is a new channel available? if so swap to that one
 	if !r.isStarted.Load() {

pkg/telemetry/prometheus/node.go

@@ -4,6 +4,7 @@ import (
 	"time"
 
 	"github.com/mackerelio/go-osstat/loadavg"
+	"github.com/mackerelio/go-osstat/memory"
 	"github.com/prometheus/client_golang/prometheus"
 	"go.uber.org/atomic"
 
@@ -84,6 +85,18 @@ func Init(nodeID string) {
 	initRoomStats(nodeID)
 }
 
+func getMemoryStats() (memoryLoad float32, err error) {
+	memInfo, err := memory.Get()
+	if err != nil {
+		return
+	}
+
+	if memInfo.Total != 0 {
+		memoryLoad = float32(memInfo.Used) / float32(memInfo.Total)
+	}
+	return
+}
+
 func GetUpdatedNodeStats(prev *livekit.NodeStats, prevAverage *livekit.NodeStats) (*livekit.NodeStats, bool, error) {
 	loadAvg, err := loadavg.Get()
 	if err != nil {

pkg/telemetry/prometheus/node_linux.go

@@ -9,7 +9,6 @@ import (
 
 	"github.com/florianl/go-tc"
 	"github.com/mackerelio/go-osstat/cpu"
-	"github.com/mackerelio/go-osstat/memory"
 )
 
 var (
@@ -37,16 +36,6 @@ func getCPUStats() (cpuLoad float32, numCPUs uint32, err error) {
 	return
 }
 
-func getMemoryStats() (memoryLoad float32, err error) {
-	memInfo, err := memory.Get()
-	if err != nil {
-		return
-	}
-
-	memoryLoad = float32(memInfo.Used) / float32(memInfo.Total)
-	return
-}
-
 func getTCStats() (packets, drops uint32, err error) {
 	rtnl, err := tc.Open(&tc.Config{})
 	if err != nil {

pkg/telemetry/prometheus/node_nonlinux.go

@@ -7,7 +7,6 @@ import (
 	"sync"
 
 	"github.com/mackerelio/go-osstat/cpu"
-	"github.com/mackerelio/go-osstat/memory"
 )
 
 var (
@@ -35,16 +34,6 @@ func getCPUStats() (cpuLoad float32, numCPUs uint32, err error) {
 	return
 }
 
-func getMemoryStats() (memoryLoad float32, err error) {
-	memInfo, err := memory.Get()
-	if err != nil {
-		return
-	}
-
-	memoryLoad = float32(memInfo.Used) / float32(memInfo.Total)
-	return
-}
-
 func getTCStats() (packets, drops uint32, err error) {
 	// linux only
 	return