Files
cheesy-arena-lite/bandwidth_monitor.go
2015-06-20 23:54:14 -07:00

109 lines
3.8 KiB
Go

// Copyright 2015 Team 254. All Rights Reserved.
// Author: pat@patfairbank.com (Patrick Fairbank)
//
// Methods for monitoring team bandwidth usage across a managed switch.
package main
import (
"fmt"
"github.com/cdevr/WapSNMP"
"log"
"time"
)
const (
monitoringIntervalMs = 1000
toRobotBytesOid = ".1.3.6.1.2.1.2.2.1.10"
fromRobotBytesOid = ".1.3.6.1.2.1.2.2.1.16"
red1Port = 2
red2Port = 4
red3Port = 6
blue1Port = 8
blue2Port = 10
blue3Port = 12
)
type BandwidthMonitor struct {
snmpClient *wapsnmp.WapSNMP
toRobotOid wapsnmp.Oid
fromRobotOid wapsnmp.Oid
lastToRobotBytes map[string]interface{}
lastFromRobotBytes map[string]interface{}
lastBytesTime time.Time
}
// Loops indefinitely to query the managed switch via SNMP (Simple Network Management Protocol).
func MonitorBandwidth() {
monitor := BandwidthMonitor{toRobotOid: wapsnmp.MustParseOid(toRobotBytesOid),
fromRobotOid: wapsnmp.MustParseOid(fromRobotBytesOid)}
for {
if eventSettings.NetworkSecurityEnabled && eventSettings.BandwidthMonitoringEnabled {
err := monitor.updateBandwidth()
if err != nil {
log.Printf("Bandwidth monitoring error: %s", err)
}
}
time.Sleep(time.Millisecond * monitoringIntervalMs)
}
}
func (monitor *BandwidthMonitor) updateBandwidth() error {
if monitor.snmpClient != nil && monitor.snmpClient.Target != eventSettings.SwitchAddress {
// Switch address has changed; must re-create the SNMP client.
monitor.snmpClient.Close()
monitor.snmpClient = nil
}
if monitor.snmpClient == nil {
var err error
monitor.snmpClient, err = wapsnmp.NewWapSNMP(eventSettings.SwitchAddress, eventSettings.SwitchPassword,
wapsnmp.SNMPv2c, 2*time.Second, 0)
if err != nil {
return err
}
}
// Retrieve total number of bytes sent/received per port.
toRobotBytes, err := monitor.snmpClient.GetTable(monitor.toRobotOid)
if err != nil {
return err
}
fromRobotBytes, err := monitor.snmpClient.GetTable(monitor.fromRobotOid)
if err != nil {
return err
}
// Calculate the bandwidth usage over time.
monitor.updateStationBandwidth("R1", red1Port, toRobotBytes, fromRobotBytes)
monitor.updateStationBandwidth("R2", red2Port, toRobotBytes, fromRobotBytes)
monitor.updateStationBandwidth("R3", red3Port, toRobotBytes, fromRobotBytes)
monitor.updateStationBandwidth("B1", blue1Port, toRobotBytes, fromRobotBytes)
monitor.updateStationBandwidth("B2", blue2Port, toRobotBytes, fromRobotBytes)
monitor.updateStationBandwidth("B3", blue3Port, toRobotBytes, fromRobotBytes)
monitor.lastToRobotBytes = toRobotBytes
monitor.lastFromRobotBytes = fromRobotBytes
monitor.lastBytesTime = time.Now()
return nil
}
func (monitor *BandwidthMonitor) updateStationBandwidth(station string, port int, toRobotBytes map[string]interface{},
fromRobotBytes map[string]interface{}) {
dsConn := mainArena.AllianceStations[station].DsConn
if dsConn == nil {
// No team assigned; just skip it.
return
}
dsStatus := dsConn.DriverStationStatus
secondsSinceLast := time.Now().Sub(monitor.lastBytesTime).Seconds()
toRobotBytesForPort := uint32(toRobotBytes[fmt.Sprintf("%s.%d", toRobotBytesOid, port)].(wapsnmp.Counter))
lastToRobotBytesForPort := uint32(monitor.lastToRobotBytes[fmt.Sprintf("%s.%d", toRobotBytesOid, port)].(wapsnmp.Counter))
dsStatus.MBpsToRobot = float64(toRobotBytesForPort-lastToRobotBytesForPort) / 1024 / 1024 / secondsSinceLast
fromRobotBytesForPort := uint32(fromRobotBytes[fmt.Sprintf("%s.%d", fromRobotBytesOid, port)].(wapsnmp.Counter))
lastFromRobotBytesForPort := uint32(monitor.lastFromRobotBytes[fmt.Sprintf("%s.%d", fromRobotBytesOid, port)].(wapsnmp.Counter))
dsStatus.MBpsFromRobot = float64(fromRobotBytesForPort-lastFromRobotBytesForPort) / 1024 / 1024 / secondsSinceLast
}