How to use

OperationalStatsService

in

co.cask.cdap.operations

@Override
protected void run() {
 while (isRunning()) {
  try {
   collectOperationalStats();
   if (!isRunning()) {
    // Need to check here before sleep as the collectOperationStats may swallow interrupted exception
    break;
   }
   TimeUnit.SECONDS.sleep(statsRefreshInterval);
  } catch (InterruptedException e) {
   // Expected on stopping. So just break the loop
   break;
  }
 }
}

@Override
protected void shutDown() throws Exception {
 MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
 for (Map.Entry<OperationalExtensionId, OperationalStats> entry : operationalStatsLoader.getAll().entrySet()) {
  OperationalStats operationalStats = entry.getValue();
  ObjectName objectName = getObjectName(operationalStats);
  if (objectName == null) {
   LOG.warn("Found an operational extension with null service name and stat type while unregistering - {}. " +
         "Ignoring this extension.", operationalStats.getClass().getName());
   continue;
  }
  try {
   mbs.unregisterMBean(objectName);
  } catch (InstanceNotFoundException e) {
   LOG.warn("MBean {} not found while un-registering. Ignoring.", objectName);
  } catch (MBeanRegistrationException e) {
   LOG.warn("Error while un-registering MBean {}.", e);
  }
  operationalStats.destroy();
 }
 LOG.info("Successfully shutdown operational stats service.");
}

/**
 * Collects stats from all {@link OperationalStats}.
 */
private void collectOperationalStats() throws InterruptedException {
 LOG.trace("Running operational stats extension service iteration");
 for (Map.Entry<OperationalExtensionId, OperationalStats> entry : operationalStatsLoader.getAll().entrySet()) {
  if (!isRunning()) {
   return;
  }
  OperationalStats stats = entry.getValue();
  LOG.trace("Collecting stats for service {} of type {}", stats.getServiceName(), stats.getStatType());
  try {
   stats.collect();
  } catch (Throwable t) {
   Throwables.propagateIfInstanceOf(t, InterruptedException.class);
   Throwable rootCause = Throwables.getRootCause(t);
   if (rootCause instanceof ServiceUnavailableException || rootCause instanceof TException) {
    // Required service (for example DatasetService in case of ServiceUnavailableException
    // or Transaction Service in case of TException) is not running yet.
    // Return without logging.
    return;
   }
   if (rootCause instanceof InterruptedException) {
    throw (InterruptedException) rootCause;
   }
   READ_FAILURE_LOG.warn("Failed to collect stats for service {} of type {} due to {}",
              stats.getServiceName(), stats.getStatType(), rootCause.getMessage());
  }
 }
}

operationalStatsService.startAndWait();

operationalStatsService.stopAndWait();

/**
 * Collects stats from all {@link OperationalStats}.
 */
private void collectOperationalStats() throws InterruptedException {
 LOG.trace("Running operational stats extension service iteration");
 for (Map.Entry<OperationalExtensionId, OperationalStats> entry : operationalStatsLoader.getAll().entrySet()) {
  if (!isRunning()) {
   return;
  }
  OperationalStats stats = entry.getValue();
  LOG.trace("Collecting stats for service {} of type {}", stats.getServiceName(), stats.getStatType());
  try {
   stats.collect();
  } catch (Throwable t) {
   Throwables.propagateIfInstanceOf(t, InterruptedException.class);
   Throwable rootCause = Throwables.getRootCause(t);
   if (rootCause instanceof ServiceUnavailableException || rootCause instanceof TException) {
    // Required service (for example DatasetService in case of ServiceUnavailableException
    // or Transaction Service in case of TException) is not running yet.
    // Return without logging.
    return;
   }
   if (rootCause instanceof InterruptedException) {
    throw (InterruptedException) rootCause;
   }
   READ_FAILURE_LOG.warn("Failed to collect stats for service {} of type {} due to {}",
              stats.getServiceName(), stats.getStatType(), rootCause.getMessage());
  }
 }
}

operationalStatsService.startAndWait();

operationalStatsService.stopAndWait();

@Override
protected void run() {
 while (isRunning()) {
  try {
   collectOperationalStats();
   if (!isRunning()) {
    // Need to check here before sleep as the collectOperationStats may swallow interrupted exception
    break;
   }
   TimeUnit.SECONDS.sleep(statsRefreshInterval);
  } catch (InterruptedException e) {
   // Expected on stopping. So just break the loop
   break;
  }
 }
}

@Override
protected void shutDown() throws Exception {
 MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
 for (Map.Entry<OperationalExtensionId, OperationalStats> entry : operationalStatsLoader.getAll().entrySet()) {
  OperationalStats operationalStats = entry.getValue();
  ObjectName objectName = getObjectName(operationalStats);
  if (objectName == null) {
   LOG.warn("Found an operational extension with null service name and stat type while unregistering - {}. " +
         "Ignoring this extension.", operationalStats.getClass().getName());
   continue;
  }
  try {
   mbs.unregisterMBean(objectName);
  } catch (InstanceNotFoundException e) {
   LOG.warn("MBean {} not found while un-registering. Ignoring.", objectName);
  } catch (MBeanRegistrationException e) {
   LOG.warn("Error while un-registering MBean {}.", e);
  }
  operationalStats.destroy();
 }
 LOG.info("Successfully shutdown operational stats service.");
}

/**
 * Registers all JMX {@link MXBean MXBeans} from {@link OperationalStats} extensions in the extensions directory.
 */
@Override
protected void startUp() throws Exception {
 runThread = Thread.currentThread();
 MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
 for (Map.Entry<OperationalExtensionId, OperationalStats> entry : operationalStatsLoader.getAll().entrySet()) {
  OperationalStats operationalStats = entry.getValue();
  ObjectName objectName = getObjectName(operationalStats);
  if (objectName == null) {
   LOG.warn("Found an operational extension with null service name and stat type - {}. Ignoring this extension.",
        OperationalStats.class.getName());
   continue;
  }
  LOG.debug("Registering operational extension: {}; extension id: {}", operationalStats, entry.getKey());
  // initialize operational stats
  operationalStats.initialize(injector);
  // register MBean
  mbs.registerMBean(operationalStats, objectName);
 }
 LOG.info("Successfully started Operational Stats Service...");
}

/**
 * Registers all JMX {@link MXBean MXBeans} from {@link OperationalStats} extensions in the extensions directory.
 */
@Override
protected void startUp() throws Exception {
 runThread = Thread.currentThread();
 MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
 for (Map.Entry<OperationalExtensionId, OperationalStats> entry : operationalStatsLoader.getAll().entrySet()) {
  OperationalStats operationalStats = entry.getValue();
  ObjectName objectName = getObjectName(operationalStats);
  if (objectName == null) {
   LOG.warn("Found an operational extension with null service name and stat type - {}. Ignoring this extension.",
        OperationalStats.class.getName());
   continue;
  }
  LOG.debug("Registering operational extension: {}; extension id: {}", operationalStats, entry.getKey());
  // initialize operational stats
  operationalStats.initialize(injector);
  // register MBean
  mbs.registerMBean(operationalStats, objectName);
 }
 LOG.info("Successfully started Operational Stats Service...");
}