diff --git a/metrics/pom.xml b/metrics/pom.xml index c4b433482b..189f9afbff 100644 --- a/metrics/pom.xml +++ b/metrics/pom.xml @@ -23,5 +23,30 @@ metrics-core ${dep.ver.metrics} + + io.dropwizard.metrics + metrics-healthchecks + ${dep.ver.metrics} + + + io.dropwizard.metrics + metrics-servlets + ${dep.ver.metrics} + + + io.dropwizard.metrics + metrics-servlet + ${dep.ver.metrics} + + + javax.servlet + javax.servlet-api + 3.1.0 + + + junit + junit + 4.12 + \ No newline at end of file diff --git a/metrics/src/main/java/com/baeldung/metrics/core/ActiveUserCountGauge.java b/metrics/src/main/java/com/baeldung/metrics/core/ActiveUserCountGauge.java new file mode 100644 index 0000000000..f14e7b520a --- /dev/null +++ b/metrics/src/main/java/com/baeldung/metrics/core/ActiveUserCountGauge.java @@ -0,0 +1,17 @@ +package com.baeldung.metrics.core; + +import java.util.List; + +import com.codahale.metrics.DerivativeGauge; +import com.codahale.metrics.Gauge; + +public class ActiveUserCountGauge extends DerivativeGauge, Integer> { + public ActiveUserCountGauge(Gauge> base) { + super(base); + } + + @Override + protected Integer transform(List value) { + return value.size(); + } +} diff --git a/metrics/src/main/java/com/baeldung/metrics/core/ActiveUsersGauge.java b/metrics/src/main/java/com/baeldung/metrics/core/ActiveUsersGauge.java new file mode 100644 index 0000000000..79ac132e0b --- /dev/null +++ b/metrics/src/main/java/com/baeldung/metrics/core/ActiveUsersGauge.java @@ -0,0 +1,25 @@ +package com.baeldung.metrics.core; + +import java.util.ArrayList; +import java.util.List; +import java.util.concurrent.TimeUnit; + +import com.codahale.metrics.CachedGauge; + +public class ActiveUsersGauge extends CachedGauge> { + public ActiveUsersGauge(long timeout, TimeUnit timeoutUnit) { + super(timeout, timeoutUnit); + } + + @Override + protected List loadValue() { + return getActiveUserCount(); + } + + private List getActiveUserCount() { + // mock reading from database and count the active users, return a fixed value + List result = new ArrayList(); + result.add(12L); + return result; + } +} diff --git a/metrics/src/main/java/com/baeldung/metrics/core/AttendanceRatioGauge.java b/metrics/src/main/java/com/baeldung/metrics/core/AttendanceRatioGauge.java new file mode 100644 index 0000000000..e4cdca6b0a --- /dev/null +++ b/metrics/src/main/java/com/baeldung/metrics/core/AttendanceRatioGauge.java @@ -0,0 +1,18 @@ +package com.baeldung.metrics.core; + +import com.codahale.metrics.RatioGauge; + +public class AttendanceRatioGauge extends RatioGauge { + private int attendanceCount; + private int courseCount; + + public AttendanceRatioGauge(int attendanceCount, int courseCount) { + this.attendanceCount = attendanceCount; + this.courseCount = courseCount; + } + + @Override + protected Ratio getRatio() { + return Ratio.of(attendanceCount, courseCount); + } +} diff --git a/metrics/src/main/java/com/baeldung/metrics/core/MetricsDemo.java b/metrics/src/main/java/com/baeldung/metrics/core/MetricsDemo.java deleted file mode 100644 index 3f3127fd5a..0000000000 --- a/metrics/src/main/java/com/baeldung/metrics/core/MetricsDemo.java +++ /dev/null @@ -1,4 +0,0 @@ -package com.baeldung.metrics.core; - -public class MetricsDemo { -} diff --git a/metrics/src/main/java/com/baeldung/metrics/core/MetricsRegistryDemo.java b/metrics/src/main/java/com/baeldung/metrics/core/MetricsRegistryDemo.java deleted file mode 100644 index fe390d5534..0000000000 --- a/metrics/src/main/java/com/baeldung/metrics/core/MetricsRegistryDemo.java +++ /dev/null @@ -1,6 +0,0 @@ -package com.baeldung.metrics.core; - -public class MetricsRegistryDemo { - public static void main(String[] args) { - } -} diff --git a/metrics/src/main/java/com/baeldung/metrics/healthchecks/DatabaseHealthCheck.java b/metrics/src/main/java/com/baeldung/metrics/healthchecks/DatabaseHealthCheck.java new file mode 100644 index 0000000000..46170f627f --- /dev/null +++ b/metrics/src/main/java/com/baeldung/metrics/healthchecks/DatabaseHealthCheck.java @@ -0,0 +1,10 @@ +package com.baeldung.metrics.healthchecks; + +import com.codahale.metrics.health.HealthCheck; + +public class DatabaseHealthCheck extends HealthCheck { + @Override + protected Result check() throws Exception { + return HealthCheck.Result.healthy(); + } +} diff --git a/metrics/src/main/java/com/baeldung/metrics/healthchecks/UserCenterHealthCheck.java b/metrics/src/main/java/com/baeldung/metrics/healthchecks/UserCenterHealthCheck.java new file mode 100644 index 0000000000..481ced142d --- /dev/null +++ b/metrics/src/main/java/com/baeldung/metrics/healthchecks/UserCenterHealthCheck.java @@ -0,0 +1,10 @@ +package com.baeldung.metrics.healthchecks; + +import com.codahale.metrics.health.HealthCheck; + +public class UserCenterHealthCheck extends HealthCheck { + @Override + protected Result check() throws Exception { + return Result.healthy(); + } +} diff --git a/metrics/src/main/java/com/baeldung/metrics/servlet/MyInstrumentedFilterContextListener.java b/metrics/src/main/java/com/baeldung/metrics/servlet/MyInstrumentedFilterContextListener.java new file mode 100644 index 0000000000..3036eeeb23 --- /dev/null +++ b/metrics/src/main/java/com/baeldung/metrics/servlet/MyInstrumentedFilterContextListener.java @@ -0,0 +1,13 @@ +package com.baeldung.metrics.servlet; + +import com.codahale.metrics.MetricRegistry; +import com.codahale.metrics.servlet.InstrumentedFilterContextListener; + +public class MyInstrumentedFilterContextListener extends InstrumentedFilterContextListener { + public static final MetricRegistry REGISTRY = new MetricRegistry(); + + @Override + protected MetricRegistry getMetricRegistry() { + return REGISTRY; + } +} diff --git a/metrics/src/main/java/com/baeldung/metrics/servlets/MyHealthCheckServletContextListener.java b/metrics/src/main/java/com/baeldung/metrics/servlets/MyHealthCheckServletContextListener.java new file mode 100644 index 0000000000..12f12b3e6f --- /dev/null +++ b/metrics/src/main/java/com/baeldung/metrics/servlets/MyHealthCheckServletContextListener.java @@ -0,0 +1,18 @@ +package com.baeldung.metrics.servlets; + +import com.baeldung.metrics.healthchecks.DatabaseHealthCheck; +import com.codahale.metrics.health.HealthCheckRegistry; +import com.codahale.metrics.servlets.HealthCheckServlet; + +public class MyHealthCheckServletContextListener extends HealthCheckServlet.ContextListener { + public static final HealthCheckRegistry HEALTH_CHECK_REGISTRY = new HealthCheckRegistry(); + + static { + HEALTH_CHECK_REGISTRY.register("db", new DatabaseHealthCheck()); + } + + @Override + protected HealthCheckRegistry getHealthCheckRegistry() { + return HEALTH_CHECK_REGISTRY; + } +} diff --git a/metrics/src/main/java/com/baeldung/metrics/servlets/MyMetricsServletContextListener.java b/metrics/src/main/java/com/baeldung/metrics/servlets/MyMetricsServletContextListener.java new file mode 100644 index 0000000000..7b4f33447a --- /dev/null +++ b/metrics/src/main/java/com/baeldung/metrics/servlets/MyMetricsServletContextListener.java @@ -0,0 +1,25 @@ +package com.baeldung.metrics.servlets; + +import com.codahale.metrics.Counter; +import com.codahale.metrics.Histogram; +import com.codahale.metrics.MetricRegistry; +import com.codahale.metrics.servlets.MetricsServlet; + +public class MyMetricsServletContextListener extends MetricsServlet.ContextListener { + private static final MetricRegistry METRIC_REGISTRY = new MetricRegistry(); + + static { + Counter counter = METRIC_REGISTRY.counter("m01-counter"); + counter.inc(); + + Histogram histogram = METRIC_REGISTRY.histogram("m02-histogram"); + histogram.update(5); + histogram.update(20); + histogram.update(100); + } + + @Override + protected MetricRegistry getMetricRegistry() { + return METRIC_REGISTRY; + } +} diff --git a/metrics/src/test/java/com/baeldung/metrics/core/MetricsTest.java b/metrics/src/test/java/com/baeldung/metrics/core/MetricsTest.java new file mode 100644 index 0000000000..b9bcc6a5fe --- /dev/null +++ b/metrics/src/test/java/com/baeldung/metrics/core/MetricsTest.java @@ -0,0 +1,139 @@ +package com.baeldung.metrics.core; + +import static org.hamcrest.CoreMatchers.equalTo; +import static org.junit.Assert.assertEquals; +import static org.junit.Assert.assertThat; + +import java.util.ArrayList; +import java.util.List; +import java.util.concurrent.TimeUnit; + +import org.junit.Test; + +import com.codahale.metrics.*; + +public class MetricsTest { + @Test + public void testMeter() throws InterruptedException { + Meter meter = new Meter(); + + long initCount = meter.getCount(); + assertThat(initCount, equalTo(0L)); + + meter.mark(); + assertThat(meter.getCount(), equalTo(1L)); + + meter.mark(20); + assertThat(meter.getCount(), equalTo(21L)); + + // not use assert for these rate values because they change every time when this test is run + double meanRate = meter.getMeanRate(); + double oneMinRate = meter.getOneMinuteRate(); + double fiveMinRate = meter.getFiveMinuteRate(); + double fifteenMinRate = meter.getFifteenMinuteRate(); + System.out.println(meanRate); + System.out.println(oneMinRate); + System.out.println(fiveMinRate); + System.out.println(fifteenMinRate); + } + + @Test + public void testRatioGauge() { + Gauge ratioGauge = new AttendanceRatioGauge(15, 20); + assertThat(ratioGauge.getValue(), equalTo(0.75)); + } + + @Test + public void testCacheGauge() { + Gauge> activeUsersGauge = new ActiveUsersGauge(15, TimeUnit.MINUTES); + List expected = new ArrayList(); + expected.add(12L); + assertThat(activeUsersGauge.getValue(), equalTo(expected)); + } + + @Test + public void testDerivativeGauge() { + Gauge> activeUsersGauge = new ActiveUsersGauge(15, TimeUnit.MINUTES); + Gauge activeUserCountGauge = new ActiveUserCountGauge(activeUsersGauge); + assertThat(activeUserCountGauge.getValue(), equalTo(1)); + } + + @Test + public void testCounter() { + Counter counter = new Counter(); + + long initCount = counter.getCount(); + assertThat(initCount, equalTo(0L)); + + counter.inc(); + assertThat(counter.getCount(), equalTo(1L)); + + counter.inc(11); + assertThat(counter.getCount(), equalTo(12L)); + + counter.dec(); + assertThat(counter.getCount(), equalTo(11L)); + + counter.dec(6); + assertThat(counter.getCount(), equalTo(5L)); + } + + @Test + public void testHistogram() { + Histogram histogram = new Histogram(new UniformReservoir()); + + histogram.update(5); + long count1 = histogram.getCount(); + assertThat(count1, equalTo(1L)); + Snapshot snapshot1 = histogram.getSnapshot(); + assertThat(snapshot1.getValues().length, equalTo(1)); + assertThat(snapshot1.getValues()[0], equalTo(5L)); + assertThat(snapshot1.getMax(), equalTo(5L)); + assertThat(snapshot1.getMin(), equalTo(5L)); + assertThat(snapshot1.getMean(), equalTo(5.0)); + assertThat(snapshot1.getMedian(), equalTo(5.0)); + assertThat(snapshot1.getStdDev(), equalTo(0.0)); + assertThat(snapshot1.get75thPercentile(), equalTo(5.0)); + assertThat(snapshot1.get95thPercentile(), equalTo(5.0)); + assertThat(snapshot1.get98thPercentile(), equalTo(5.0)); + assertThat(snapshot1.get99thPercentile(), equalTo(5.0)); + assertThat(snapshot1.get999thPercentile(), equalTo(5.0)); + + histogram.update(20); + long count2 = histogram.getCount(); + assertThat(count2, equalTo(2L)); + Snapshot snapshot2 = histogram.getSnapshot(); + assertThat(snapshot2.getValues().length, equalTo(2)); + assertThat(snapshot2.getValues()[0], equalTo(5L)); + assertThat(snapshot2.getValues()[1], equalTo(20L)); + assertThat(snapshot2.getMax(), equalTo(20L)); + assertThat(snapshot2.getMin(), equalTo(5L)); + assertThat(snapshot2.getMean(), equalTo(12.5)); + assertThat(snapshot2.getMedian(), equalTo(12.5)); + assertEquals(10.6, snapshot2.getStdDev(), 0.1); + assertThat(snapshot2.get75thPercentile(), equalTo(20.0)); + assertThat(snapshot2.get95thPercentile(), equalTo(20.0)); + assertThat(snapshot2.get98thPercentile(), equalTo(20.0)); + assertThat(snapshot2.get99thPercentile(), equalTo(20.0)); + assertThat(snapshot2.get999thPercentile(), equalTo(20.0)); + } + + @Test + public void testTimer() throws InterruptedException { + Timer timer = new Timer(); + + Timer.Context context1 = timer.time(); + TimeUnit.SECONDS.sleep(5); + + long elapsed1 = context1.stop(); + assertEquals(5000000000L, elapsed1, 1000000); + assertThat(timer.getCount(), equalTo(1L)); + assertEquals(0.2, timer.getMeanRate(), 0.1); + + Timer.Context context2 = timer.time(); + TimeUnit.SECONDS.sleep(2); + context2.close(); + assertThat(timer.getCount(), equalTo(2L)); + assertEquals(0.3, timer.getMeanRate(), 0.1); + } +} diff --git a/metrics/src/test/java/com/baeldung/metrics/core/ReporterTest.java b/metrics/src/test/java/com/baeldung/metrics/core/ReporterTest.java new file mode 100644 index 0000000000..4676f8c3a4 --- /dev/null +++ b/metrics/src/test/java/com/baeldung/metrics/core/ReporterTest.java @@ -0,0 +1,33 @@ +package com.baeldung.metrics.core; + +import java.util.concurrent.TimeUnit; + +import org.junit.Test; + +import com.codahale.metrics.*; + +public class ReporterTest { + @Test + public void testConsoleReporter() { + MetricRegistry metricRegistry = new MetricRegistry(); + + Meter meter = metricRegistry.meter("meter"); + meter.mark(); + meter.mark(200); + Histogram histogram = metricRegistry.histogram("histogram"); + histogram.update(12); + histogram.update(17); + histogram.update(20); + Counter counter = metricRegistry.counter("counter"); + counter.inc(); + counter.dec(); + counter.inc(); + counter.inc(); + counter.inc(); + counter.inc(); + + ConsoleReporter reporter = ConsoleReporter.forRegistry(metricRegistry).build(); + reporter.start(5, TimeUnit.MICROSECONDS); + reporter.report(); + } +} diff --git a/metrics/src/test/java/com/baeldung/metrics/healthchecks/HealthCheckTest.java b/metrics/src/test/java/com/baeldung/metrics/healthchecks/HealthCheckTest.java new file mode 100644 index 0000000000..4cefc9f3a0 --- /dev/null +++ b/metrics/src/test/java/com/baeldung/metrics/healthchecks/HealthCheckTest.java @@ -0,0 +1,31 @@ +package com.baeldung.metrics.healthchecks; + +import static org.hamcrest.CoreMatchers.equalTo; +import static org.junit.Assert.assertThat; + +import java.util.Map; + +import org.junit.Test; + +import com.codahale.metrics.health.HealthCheck; +import com.codahale.metrics.health.HealthCheckRegistry; + +public class HealthCheckTest { + @Test + public void testHealthCheck() { + HealthCheckRegistry healthCheckRegistry = new HealthCheckRegistry(); + + healthCheckRegistry.register("db", new DatabaseHealthCheck()); + healthCheckRegistry.register("uc", new UserCenterHealthCheck()); + + assertThat(healthCheckRegistry.getNames().size(), equalTo(2)); + + Map results = healthCheckRegistry.runHealthChecks(); + for (Map.Entry entry : results.entrySet()) { + assertThat(entry.getValue().isHealthy(), equalTo(true)); + } + + healthCheckRegistry.unregister("uc"); + assertThat(healthCheckRegistry.getNames().size(), equalTo(1)); + } +} \ No newline at end of file