AMBARI-16080. Delete Service: Deleting Hive fails with 500 error (smohanty)

ambari-server/src/main/java/org/apache/ambari/server/state/ServiceComponentImpl.java

@@ -678,10 +678,9 @@ public class ServiceComponentImpl implements ServiceComponent {
     try {
       readWriteLock.readLock().lock();
       try {
-        if (!getDesiredState().isRemovableState()) {
-          return false;
-        }
-
+        // A component can be deleted if all it's host components
+        // can be removed, irrespective of the state of
+        // the component itself
         for (ServiceComponentHost sch : hostComponents.values()) {
           if (!sch.canBeRemoved()) {
             LOG.warn("Found non removable hostcomponent when trying to"
@@ -689,7 +688,7 @@ public class ServiceComponentImpl implements ServiceComponent {
                 + ", clusterName=" + getClusterName()
                 + ", serviceName=" + getServiceName()
                 + ", componentName=" + getName()
-                + ", recoveryEnabled=" + isRecoveryEnabled()
+                + ", state=" + sch.getState()
                 + ", hostname=" + sch.getHostName());
             return false;
           }

ambari-server/src/test/java/org/apache/ambari/server/state/ServiceComponentTest.java

@@ -341,19 +341,26 @@ public class ServiceComponentTest {
   }
 
   @Test
-  public void testCanBeRemoved() throws Exception{
+  public void testCanBeRemoved() throws Exception {
     String componentName = "NAMENODE";
     ServiceComponent component = serviceComponentFactory.createNew(service,
-        componentName);
+                                                                   componentName);
+    addHostToCluster("h1", service.getCluster().getClusterName());
+    ServiceComponentHost sch = serviceComponentHostFactory.createNew(component, "h1");
+    component.addServiceComponentHost(sch);
 
     for (State state : State.values()) {
       component.setDesiredState(state);
 
-      if (state.isRemovableState()) {
-        org.junit.Assert.assertTrue(component.canBeRemoved());
-      }
-      else {
-        org.junit.Assert.assertFalse(component.canBeRemoved());
+      for (State hcState : State.values()) {
+        sch.setDesiredState(hcState);
+        sch.setState(hcState);
+
+        if (hcState.isRemovableState()) {
+          org.junit.Assert.assertTrue(component.canBeRemoved());
+        } else {
+          org.junit.Assert.assertFalse(component.canBeRemoved());
+        }
       }
     }
   }
@@ -399,6 +406,69 @@ public class ServiceComponentTest {
     Assert.assertEquals(history, serviceComponentDesiredStateEntity.getHistory().iterator().next());
   }
 
+
+  @Test
+  public void testServiceComponentRemove() throws AmbariException {
+    ServiceComponentDesiredStateDAO serviceComponentDesiredStateDAO = injector.getInstance(
+        ServiceComponentDesiredStateDAO.class);
+
+    String componentName = "NAMENODE";
+    ServiceComponent component = serviceComponentFactory.createNew(service, componentName);
+    service.addServiceComponent(component);
+    component.persist();
+
+    ServiceComponent sc = service.getServiceComponent(componentName);
+    Assert.assertNotNull(sc);
+
+    sc.setDesiredState(State.STARTED);
+    Assert.assertEquals(State.STARTED, sc.getDesiredState());
+
+    ServiceComponentDesiredStateEntity serviceComponentDesiredStateEntity = serviceComponentDesiredStateDAO.findByName(
+        cluster.getClusterId(), serviceName, componentName);
+
+    Assert.assertNotNull(serviceComponentDesiredStateEntity);
+
+    Assert.assertTrue(sc.getServiceComponentHosts().isEmpty());
+
+    addHostToCluster("h1", service.getCluster().getClusterName());
+    addHostToCluster("h2", service.getCluster().getClusterName());
+
+    HostEntity hostEntity1 = hostDAO.findByName("h1");
+    assertNotNull(hostEntity1);
+
+    ServiceComponentHost sch1 =
+        serviceComponentHostFactory.createNew(sc, "h1");
+    ServiceComponentHost sch2 =
+        serviceComponentHostFactory.createNew(sc, "h2");
+
+    Map<String, ServiceComponentHost> compHosts =
+        new HashMap<String, ServiceComponentHost>();
+    compHosts.put("h1", sch1);
+    compHosts.put("h2", sch2);
+    sc.addServiceComponentHosts(compHosts);
+
+    sch1.setState(State.STARTED);
+    sch2.setState(State.STARTED);
+
+    try {
+      // delete the SC
+      sc.delete();
+      Assert.assertTrue("Delete must fail as some SCH are in STARTED state", false);
+    }catch(AmbariException e) {
+      // expected
+    }
+
+    sch1.setState(State.INSTALLED);
+    sch2.setState(State.INSTALL_FAILED);
+    sc.delete();
+
+    // verify history is gone, too
+    serviceComponentDesiredStateEntity = serviceComponentDesiredStateDAO.findByName(
+        cluster.getClusterId(), serviceName, componentName);
+
+    Assert.assertNull(serviceComponentDesiredStateEntity);
+ }
+
   /**
    * Tests the CASCADE nature of removing a service component also removes the
    * history.