From e0f40d3d0cb67fa62657bce9c582a9f0ded49991 Mon Sep 17 00:00:00 2001
From: David Colburn <xero73@gmail.com>
Date: Fri, 15 Dec 2023 09:33:23 -0800
Subject: [PATCH] new strategy

---
 pkg/stats/monitor.go | 65 ++++++++++++++++++++++++++------------------
 1 file changed, 38 insertions(+), 27 deletions(-)

diff --git a/pkg/stats/monitor.go b/pkg/stats/monitor.go
index 08958a7d..1332874c 100644
--- a/pkg/stats/monitor.go
+++ b/pkg/stats/monitor.go
@@ -16,6 +16,7 @@ package stats
 
 import (
 	"fmt"
+	"math"
 	"sort"
 	"sync"
 	"time"
@@ -47,7 +48,7 @@ type Monitor struct {
 	prevEgressUsage map[string]float64
 }
 
-const cpuHoldDuration = time.Second * 10
+const cpuHoldDuration = time.Second * 30
 
 func NewMonitor(conf *config.ServiceConfig) *Monitor {
 	return &Monitor{
@@ -176,38 +177,41 @@ func (m *Monitor) CanAcceptRequest(req *rpc.StartEgressRequest) bool {
 }
 
 func (m *Monitor) canAcceptRequest(req *rpc.StartEgressRequest) bool {
-	accept := false
-	total := m.cpuStats.NumCPU()
-
-	var available float64
-	if m.requests.Load() == 0 {
-		// if no requests, use total
-		available = total - m.pendingCPUs.Load()
-	} else {
-		// if already running requests, cap usage at MaxCpuUtilization
-		available = m.cpuStats.GetCPUIdle() - m.pendingCPUs.Load() - (1-m.cpuCostConfig.MaxCpuUtilization)*total
-	}
+	available := math.Min(m.getAvailableCPU(), m.cpuStats.NumCPU()-m.pendingCPUs.Load())
 
 	logger.Debugw("cpu check",
-		"total", total,
+		"total", m.cpuStats.NumCPU(),
 		"available", available,
 		"requests", m.requests,
 	)
 
 	switch req.Request.(type) {
 	case *rpc.StartEgressRequest_RoomComposite:
-		accept = available >= m.cpuCostConfig.RoomCompositeCpuCost
+		return available >= m.cpuCostConfig.RoomCompositeCpuCost
 	case *rpc.StartEgressRequest_Web:
-		accept = available >= m.cpuCostConfig.WebCpuCost
+		return available >= m.cpuCostConfig.WebCpuCost
 	case *rpc.StartEgressRequest_Participant:
-		accept = available >= m.cpuCostConfig.ParticipantCpuCost
+		return available >= m.cpuCostConfig.ParticipantCpuCost
 	case *rpc.StartEgressRequest_TrackComposite:
-		accept = available >= m.cpuCostConfig.TrackCompositeCpuCost
+		return available >= m.cpuCostConfig.TrackCompositeCpuCost
 	case *rpc.StartEgressRequest_Track:
-		accept = available >= m.cpuCostConfig.TrackCpuCost
+		return available >= m.cpuCostConfig.TrackCpuCost
+	default:
+		logger.Warnw("unrecognized request type", nil)
+		return false
 	}
+}
+
+func (m *Monitor) getAvailableCPU() float64 {
+	total := m.cpuStats.NumCPU()
 
-	return accept
+	// if no requests, use total
+	if m.requests.Load() == 0 {
+		return total
+	}
+
+	// if already running requests, cap usage at MaxCpuUtilization
+	return m.cpuStats.GetCPUIdle() - (1-m.cpuCostConfig.MaxCpuUtilization)*total
 }
 
 func (m *Monitor) AcceptRequest(req *rpc.StartEgressRequest) error {
@@ -218,23 +222,30 @@ func (m *Monitor) AcceptRequest(req *rpc.StartEgressRequest) error {
 		return errors.ErrResourceExhausted
 	}
 
-	var cpuHold float64
+	pending := m.getAvailableCPU()
 	switch req.Request.(type) {
 	case *rpc.StartEgressRequest_RoomComposite:
-		cpuHold = m.cpuCostConfig.RoomCompositeCpuCost
+		pending = m.cpuCostConfig.RoomCompositeCpuCost
 	case *rpc.StartEgressRequest_Web:
-		cpuHold = m.cpuCostConfig.WebCpuCost
+		pending = m.cpuCostConfig.WebCpuCost
 	case *rpc.StartEgressRequest_Participant:
-		cpuHold = m.cpuCostConfig.ParticipantCpuCost
+		pending = m.cpuCostConfig.ParticipantCpuCost
 	case *rpc.StartEgressRequest_TrackComposite:
-		cpuHold = m.cpuCostConfig.TrackCompositeCpuCost
+		pending = m.cpuCostConfig.TrackCompositeCpuCost
 	case *rpc.StartEgressRequest_Track:
-		cpuHold = m.cpuCostConfig.TrackCpuCost
+		pending = m.cpuCostConfig.TrackCpuCost
 	}
 
 	m.requests.Inc()
-	m.pendingCPUs.Add(cpuHold)
-	time.AfterFunc(cpuHoldDuration, func() { m.pendingCPUs.Sub(cpuHold) })
+	m.pendingCPUs.Store(pending)
+	time.AfterFunc(cpuHoldDuration, func() {
+		m.mu.Lock()
+		if m.pendingCPUs.Load() == pending {
+			m.pendingCPUs.Store(0)
+		}
+		m.mu.Unlock()
+	})
+
 	return nil
 }