Allow configuring the max cpu usage to use when deciding whether to a…

…cceopt a request (#561)

pkg/config/service.go

@@ -33,6 +33,7 @@ const (
 	participantCpuCost    = 1
 	trackCompositeCpuCost = 1
 	trackCpuCost          = 0.5
+	maxCpuUtilization     = 0.8
 
 	defaultTemplatePort         = 7980
 	defaultTemplateBaseTemplate = "http://localhost:%d/"
@@ -50,6 +51,7 @@ type ServiceConfig struct {
 }
 
 type CPUCostConfig struct {
+	MaxCpuUtilization     float64 `yaml:"max_cpu_utilization"` // Maximum allowed CPU utilization when deciding to accept a request. Default to 80%.
 	RoomCompositeCpuCost  float64 `yaml:"room_composite_cpu_cost"`
 	WebCpuCost            float64 `yaml:"web_cpu_cost"`
 	ParticipantCpuCost    float64 `yaml:"participant_cpu_cost"`
@@ -94,6 +96,9 @@ func NewServiceConfig(confString string) (*ServiceConfig, error) {
 	if conf.TrackCpuCost <= 0 {
 		conf.TrackCpuCost = trackCpuCost
 	}
+	if conf.MaxCpuUtilization <= 0 {
+		conf.MaxCpuUtilization = maxCpuUtilization
+	}
 
 	if conf.TemplateBase == "" {
 		conf.TemplateBase = fmt.Sprintf(defaultTemplateBaseTemplate, conf.TemplatePort)

pkg/stats/monitor.go

@@ -191,8 +191,8 @@ func (m *Monitor) canAcceptRequest(req *rpc.StartEgressRequest) bool {
 		// if no requests, use total
 		available = total
 	} else {
-		// if already running requests, cap usage at 90%
-		available -= 0.1 * total
+		// if already running requests, cap usage at MaxCpuUtilization
+		available -= (1 - m.cpuCostConfig.MaxCpuUtilization) * total
 	}
 
 	switch req.Request.(type) {