Examples with NotificationStore org.apache.gobblin.metrics.callback.NotificationStore used on opensource projects

Example 1 with NotificationStore

use of org.apache.gobblin.metrics.callback.NotificationStore in project incubator-gobblin by apache.

the class RootMetricContextTest method testMetricContextLifecycle.

@Test
public void testMetricContextLifecycle() throws Exception {
    String name = UUID.randomUUID().toString();
    NotificationStore store = new NotificationStore(new ContextNamePredicate(name));
    RootMetricContext.get().addNotificationTarget(store);
    // Create a new metric context
    MetricContext metricContext = MetricContext.builder(name).build();
    WeakReference<MetricContext> contextWeakReference = new WeakReference<MetricContext>(metricContext);
    InnerMetricContext innerMetricContext = metricContext.getInnerMetricContext();
    WeakReference<InnerMetricContext> innerMetricContextWeakReference = new WeakReference<InnerMetricContext>(innerMetricContext);
    innerMetricContext = null;
    // Check that existence of a reporter does not prevent GC
    ContextStoreReporter reporter = new ContextStoreReporter("testReporter", ConfigFactory.empty());
    // Check that metric context is a child of root metric context
    Assert.assertTrue(RootMetricContext.get().getChildContextsAsMap().containsKey(name));
    Assert.assertEquals(RootMetricContext.get().getChildContextsAsMap().get(name), metricContext);
    // Check that notification on new metric context was generated
    Assert.assertEquals(store.getNotificationList().size(), 1);
    Assert.assertEquals(store.getNotificationList().get(0).getClass(), NewMetricContextNotification.class);
    Assert.assertEquals(((NewMetricContextNotification) store.getNotificationList().get(0)).getMetricContext(), metricContext);
    store.getNotificationList().clear();
    // Create a counter
    ContextAwareCounter counter1 = metricContext.contextAwareCounter("textCounter1");
    // If losing reference of counter, should not be GCed while context is present
    WeakReference<ContextAwareCounter> counterWeakReference1 = new WeakReference<ContextAwareCounter>(counter1);
    counter1 = null;
    ensureNotGarbageCollected(counterWeakReference1);
    // Create some more metrics
    ContextAwareCounter counter2 = metricContext.contextAwareCounter("testCounter");
    WeakReference<ContextAwareCounter> counterWeakReference2 = new WeakReference<ContextAwareCounter>(counter2);
    ContextAwareMeter meter = metricContext.contextAwareMeter("testMeter");
    WeakReference<ContextAwareMeter> meterWeakReference = new WeakReference<ContextAwareMeter>(meter);
    meter.mark();
    ContextAwareHistogram histogram = metricContext.contextAwareHistogram("testHistogram");
    WeakReference<ContextAwareHistogram> histogramWeakReference = new WeakReference<ContextAwareHistogram>(histogram);
    ContextAwareTimer timer = metricContext.contextAwareTimer("testTimer");
    WeakReference<ContextAwareTimer> timerWeakReference = new WeakReference<ContextAwareTimer>(timer);
    // If losing reference to context, should not be GCed while reference to metric is present
    metricContext = null;
    ensureNotGarbageCollected(contextWeakReference);
    ensureNotGarbageCollected(counterWeakReference2);
    ensureNotGarbageCollected(meterWeakReference);
    ensureNotGarbageCollected(timerWeakReference);
    ensureNotGarbageCollected(histogramWeakReference);
    // After losing reference to context and all metrics, context and all metrics should be GCed
    store.getNotificationList().clear();
    reporter.getReportedContexts().clear();
    counter2 = null;
    meter = null;
    histogram = null;
    timer = null;
    ensureGarbageCollected(contextWeakReference);
    ensureGarbageCollected(counterWeakReference1);
    ensureGarbageCollected(counterWeakReference2);
    ensureGarbageCollected(meterWeakReference);
    ensureGarbageCollected(timerWeakReference);
    ensureGarbageCollected(histogramWeakReference);
    // Inner metric context should not be GCed
    ensureNotGarbageCollected(innerMetricContextWeakReference);
    // Notification on removal of metric context should be available
    int maxWait = 10;
    while (store.getNotificationList().isEmpty() && maxWait > 0) {
        Thread.sleep(1000);
        maxWait--;
    }
    Assert.assertEquals(store.getNotificationList().size(), 1);
    Assert.assertEquals(store.getNotificationList().get(0).getClass(), MetricContextCleanupNotification.class);
    Assert.assertEquals(((MetricContextCleanupNotification) store.getNotificationList().get(0)).getMetricContext(), innerMetricContextWeakReference.get());
    // Reporter should have attempted to report metric context
    Assert.assertEquals(reporter.getReportedContexts().size(), 1);
    Assert.assertEquals(reporter.getReportedContexts().get(0), innerMetricContextWeakReference.get());
    // Metrics in deleted metric context should still be readable
    Assert.assertEquals(innerMetricContextWeakReference.get().getCounters().size(), 2);
    Assert.assertEquals(innerMetricContextWeakReference.get().getMeters().size(), 1);
    Assert.assertEquals(innerMetricContextWeakReference.get().getTimers().size(), 2);
    Assert.assertEquals(innerMetricContextWeakReference.get().getHistograms().size(), 1);
    Assert.assertEquals(innerMetricContextWeakReference.get().getMeters().get("testMeter").getCount(), 1);
    // After clearing notification, inner metric context should be GCed
    store.getNotificationList().clear();
    reporter.getReportedContexts().clear();
    ensureGarbageCollected(innerMetricContextWeakReference);
    RootMetricContext.get().removeReporter(reporter);
}