Spring Boot Actuator to Give CPU Usage

Question

I would like to know is there a way to get the CPU Usage metrics with Spring Boot Actuator? Im able to see other metrics with /metrics and /health endpoints but not getting the CPU Usage. I want to avoid writing an extra class just to see the CPU Usage. Any idea? Thanks

Answer 1

Just checked and I found this actuator... /actuator/metrics/process.cpu.usage

It outputs the following:

{
    name: "process.cpu.usage",
    description: "The "recent cpu usage" for the Java Virtual Machine process",
    baseUnit: null,
    measurements: [
        {
            statistic: "VALUE",
            value: 0.0001742149747252696
        }
    ],
    availableTags: [ ]
}

Currently using Spring Boot version 2.2.2.RELEASE.

Answer 2

Spring Boot 2 actuator solution (building on @diginoise's code to measure CPU load), registering a Gauge with a function to measure the value when requested (no need to start Threads or schedule timers):

@Component
public class CpuMetrics {

    private final static String METRICS_NAME = "process.cpu.load";

    @Autowired
    private MeterRegistry meterRegistry;

    @PostConstruct
    public void init() {
        Gauge.builder(METRICS_NAME, this, CpuMetrics::getProcessCpuLoad)
            .baseUnit("%")
            .description("CPU Load")
            .register(meterRegistry);
    }

    public Double getProcessCpuLoad() {
        try {
            MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
            ObjectName name = ObjectName.getInstance("java.lang:type=OperatingSystem");
            AttributeList list = mbs.getAttributes(name, new String[]{"ProcessCpuLoad"});

            return Optional.ofNullable(list)
                    .map(l -> l.isEmpty() ? null : l)
                    .map(List::iterator)
                    .map(Iterator::next)
                    .map(Attribute.class::cast)
                    .map(Attribute::getValue)
                    .map(Double.class::cast)
                    .orElse(null);

        } catch (Exception ex) {
            return null;
        }
    }
}

The CPU metrics will then be available at /actuator/metrics/process.cpu.load:

{
  "name": "process.cpu.load",
  "description": "CPU Load",
  "baseUnit": "%",
  "measurements": [
    {
      "statistic": "VALUE",
      "value": 0.09767676212004521
    }
  ],
  "availableTags": []
}

Answer 3

Unfortunately there isn't a CPU metric available via Spring Boot Actuator.
Fortunately you could write your own.

Just create a measuring bean which fulfills the following:

1. It has access to GaugeService as it will be tracking one value.

   @Autowired
   private GaugeService gaugeService;
   

2. Creates a thread which calls routine to measure process' CPU load:

   @PostConstruct
   public void startMeasuring() {
       new Thread() {
           @Override
           public void run() {
               gaugeService.submit("process.cpu.load", getProcessCpuLoad());
               Thread.sleep(2000);   //measure every 2sec.
           }
       }.start();
   }
   

3. Has a routine which gets CPU load for your process using MxBeans:

   public static double getProcessCpuLoad() throws Exception {
       MBeanServer mbs    = ManagementFactory.getPlatformMBeanServer();
       ObjectName name    = ObjectName.getInstance("java.lang:type=OperatingSystem");
       AttributeList list = mbs.getAttributes(name, new String[]{ "ProcessCpuLoad" });
   
       if (list.isEmpty())     return Double.NaN;
   
       Attribute att = (Attribute)list.get(0);
       Double value  = (Double)att.getValue();
   
       // usually takes a couple of seconds before we get real values
       if (value == -1.0)      return Double.NaN;
       // returns a percentage value with 1 decimal point precision
       return ((int)(value * 1000) / 10.0);
   }
   

You could also extract the system wide CPU load using this method.

Hope this helps.