content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.master.service.jvmmonitor;
  
  import alluxio.conf.Configuration;
  import alluxio.conf.PropertyKey;
  import alluxio.master.service.NoopService;
  import alluxio.master.service.SimpleService;
  import alluxio.metrics.MetricsSystem;
  
  import org.junit.After;
  import org.junit.Assert;
  import org.junit.Before;
  import org.junit.Test;
  
  /**
   * Test for Jvm pause monitor simple service.
   */
  public class JvmMonitorServiceTest {
    @Before
    public void before() {
      MetricsSystem.startSinks(Configuration.getString(PropertyKey.METRICS_CONF_FILE));
    }
  
    @After
    public void after() {
      MetricsSystem.clearAllMetrics();
      MetricsSystem.stopSinks();
    }
  
    @Test
    public void disabledServiceTest() {
      Configuration.set(PropertyKey.MASTER_JVM_MONITOR_ENABLED, false);
      SimpleService service = JvmMonitorService.Factory.create();
      Assert.assertTrue(service instanceof NoopService);
    }
  
    @Test
    public void enabledServiceTest() {
      Configuration.set(PropertyKey.MASTER_JVM_MONITOR_ENABLED, true);
      SimpleService service = JvmMonitorService.Factory.create();
      Assert.assertTrue(service instanceof JvmMonitorService);
  
      checkMetrics(0);
      service.start();
      // the expected number is 3 because the JvmMonitorService registers 3 metrics during #start()
      checkMetrics(3);
      for (int i = 0; i < 5; i++) {
        service.promote();
        checkMetrics(3);
        service.demote();
        checkMetrics(3);
      }
      service.stop();
      checkMetrics(3);
    }
  
    @Test
    public void doubleStart() {
      Configuration.set(PropertyKey.MASTER_JVM_MONITOR_ENABLED, true);
      SimpleService service = JvmMonitorService.Factory.create();
      Assert.assertTrue(service instanceof JvmMonitorService);
  
      service.start();
      Assert.assertThrows("JVM pause monitor must not already exist",
          IllegalStateException.class, service::start);
    }
  
    private void checkMetrics(int expected) {
      // the jvm monitor metrics are under the
      long count =
          MetricsSystem.allMetrics().entrySet().stream().filter(entry -> entry.getKey().contains(
              "Server.")).count();
      Assert.assertEquals(expected, count);
    }
  }
  