Centralizing repository group handling. First part.

14 files changed, 592 insertions, 232 deletions

diff --git a/archiva-modules/archiva-base/archiva-configuration/src/main/java/org/apache/archiva/configuration/ArchivaConfiguration.java b/archiva-modules/archiva-base/archiva-configuration/src/main/java/org/apache/archiva/configuration/ArchivaConfiguration.java
index 9d8ead089..f23025702 100644
--- a/archiva-modules/archiva-base/archiva-configuration/src/main/java/org/apache/archiva/configuration/ArchivaConfiguration.java
+++ b/archiva-modules/archiva-base/archiva-configuration/src/main/java/org/apache/archiva/configuration/ArchivaConfiguration.java
@@ -56,6 +56,20 @@ public interface ArchivaConfiguration
         throws RegistryException, IndeterminateConfigurationException;
 
     /**
+     * Save any updated configuration. This method allows to add a tag to the thrown event.
+     * This allows to verify the origin if the caller is the same as the listener.
+     *
+     * @param configuration the configuration to save
+     * @param eventTag the tag to add to the thrown event
+     * @throws org.apache.archiva.components.registry.RegistryException
+     *          if there is a problem saving the registry data
+     * @throws IndeterminateConfigurationException
+     *          if the configuration cannot be saved because it was read from two sources
+     */
+    void save( Configuration configuration, String eventTag )
+        throws RegistryException, IndeterminateConfigurationException;
+
+    /**
      * Determines if the configuration in use was as a result of a defaulted configuration.
      *
      * @return true if the configuration was created from the default-archiva.xml as opposed
diff --git a/archiva-modules/archiva-base/archiva-configuration/src/main/java/org/apache/archiva/configuration/ConfigurationEvent.java b/archiva-modules/archiva-base/archiva-configuration/src/main/java/org/apache/archiva/configuration/ConfigurationEvent.java
index 397c838fa..9639effbe 100644
--- a/archiva-modules/archiva-base/archiva-configuration/src/main/java/org/apache/archiva/configuration/ConfigurationEvent.java
+++ b/archiva-modules/archiva-base/archiva-configuration/src/main/java/org/apache/archiva/configuration/ConfigurationEvent.java
@@ -32,9 +32,17 @@ public class ConfigurationEvent
 
     private int type;
 
+    private String tag;
+
     public ConfigurationEvent( int type )
     {
         this.type = type;
+        tag = "";
+    }
+
+    public ConfigurationEvent(int type, String tag) {
+        this.type = type;
+        this.tag = tag;
     }
 
     public int getType()
@@ -42,35 +50,33 @@ public class ConfigurationEvent
         return type;
     }
 
+    public String getTag( )
+    {
+        return tag;
+    }
+
+    public void setTag( String tag )
+    {
+        this.tag = tag;
+    }
+
     @Override
-    public int hashCode()
+    public boolean equals( Object o )
     {
-        final int prime = 31;
-        int result = 1;
-        result = prime * result + type;
-        return result;
+        if ( this == o ) return true;
+        if ( o == null || getClass( ) != o.getClass( ) ) return false;
+
+        ConfigurationEvent that = (ConfigurationEvent) o;
+
+        if ( type != that.type ) return false;
+        return tag.equals( that.tag );
     }
 
     @Override
-    public boolean equals( Object obj )
+    public int hashCode( )
     {
-        if ( this == obj )
-        {
-            return true;
-        }
-        if ( obj == null )
-        {
-            return false;
-        }
-        if ( getClass() != obj.getClass() )
-        {
-            return false;
-        }
-        final ConfigurationEvent other = (ConfigurationEvent) obj;
-        if ( type != other.type )
-        {
-            return false;
-        }
-        return true;
+        int result = type;
+        result = 31 * result + tag.hashCode( );
+        return result;
     }
 }
diff --git a/archiva-modules/archiva-base/archiva-configuration/src/main/java/org/apache/archiva/configuration/DefaultArchivaConfiguration.java b/archiva-modules/archiva-base/archiva-configuration/src/main/java/org/apache/archiva/configuration/DefaultArchivaConfiguration.java
index 11ae70569..ee80fc8fc 100644
--- a/archiva-modules/archiva-base/archiva-configuration/src/main/java/org/apache/archiva/configuration/DefaultArchivaConfiguration.java
+++ b/archiva-modules/archiva-base/archiva-configuration/src/main/java/org/apache/archiva/configuration/DefaultArchivaConfiguration.java
@@ -410,7 +410,20 @@ public class DefaultArchivaConfiguration
 
     @SuppressWarnings("unchecked")
     @Override
-    public synchronized void save(Configuration configuration)
+    public synchronized void save(Configuration configuration) throws IndeterminateConfigurationException, RegistryException
+    {
+        save( configuration, "" );
+    }
+
+    /**
+     * Saves the configuration and adds the given tag to the event.
+     * @param configuration the configuration to save
+     * @param eventTag the tag to add to the configuration saved event
+     * @throws IndeterminateConfigurationException if the
+     * @throws RegistryException
+     */
+    @Override
+    public synchronized void save(Configuration configuration, String eventTag)
             throws IndeterminateConfigurationException, RegistryException {
         Registry section = registry.getSection(KEY + ".user");
         Registry baseSection = registry.getSection(KEY + ".base");
@@ -491,7 +504,7 @@ public class DefaultArchivaConfiguration
         this.configuration = unescapeExpressions(configuration);
         isConfigurationDefaulted = false;
 
-        triggerEvent(ConfigurationEvent.SAVED);
+        triggerEvent(ConfigurationEvent.SAVED, eventTag);
     }
 
     private void escapeCronExpressions(Configuration configuration) {
@@ -530,7 +543,7 @@ public class DefaultArchivaConfiguration
             addRegistryChangeListener(regListener);
         }
 
-        triggerEvent(ConfigurationEvent.SAVED);
+        triggerEvent(ConfigurationEvent.SAVED, "default-file");
 
         Registry section = registry.getSection(KEY + ".user");
         if (section == null) {
@@ -580,8 +593,8 @@ public class DefaultArchivaConfiguration
         }
     }
 
-    private void triggerEvent(int type) {
-        ConfigurationEvent evt = new ConfigurationEvent(type);
+    private void triggerEvent(int type, String eventTag) {
+        ConfigurationEvent evt = new ConfigurationEvent(type, eventTag);
         for (ConfigurationListener listener : listeners) {
             listener.configurationEvent(evt);
         }
diff --git a/archiva-modules/archiva-base/archiva-consumers/archiva-core-consumers/src/test/java/org/apache/archiva/consumers/core/repository/AbstractRepositoryPurgeTest.java b/archiva-modules/archiva-base/archiva-consumers/archiva-core-consumers/src/test/java/org/apache/archiva/consumers/core/repository/AbstractRepositoryPurgeTest.java
index f1791b7d0..b2f66aa7f 100644
--- a/archiva-modules/archiva-base/archiva-consumers/archiva-core-consumers/src/test/java/org/apache/archiva/consumers/core/repository/AbstractRepositoryPurgeTest.java
+++ b/archiva-modules/archiva-base/archiva-consumers/archiva-core-consumers/src/test/java/org/apache/archiva/consumers/core/repository/AbstractRepositoryPurgeTest.java
@@ -26,6 +26,7 @@ import org.apache.archiva.metadata.repository.RepositorySessionFactory;
 import org.apache.archiva.repository.ManagedRepositoryContent;
 import org.apache.archiva.repository.RepositoryRegistry;
 import org.apache.archiva.repository.base.ArchivaRepositoryRegistry;
+import org.apache.archiva.repository.base.RepositoryGroupHandler;
 import org.apache.archiva.repository.maven.metadata.storage.Maven2RepositoryPathTranslator;
 import org.apache.archiva.repository.base.BasicManagedRepository;
 import org.apache.archiva.repository.ReleaseScheme;
@@ -113,6 +114,10 @@ public abstract class AbstractRepositoryPurgeTest
     @Inject
     protected ApplicationContext applicationContext;
 
+    @SuppressWarnings( "unused" )
+    @Inject
+    RepositoryGroupHandler repositoryGroupHandler;
+
 
     @Before
     public void setUp()
diff --git a/archiva-modules/archiva-base/archiva-consumers/archiva-core-consumers/src/test/java/org/apache/archiva/consumers/core/repository/CleanupReleasedSnapshotsRepositoryPurgeTest.java b/archiva-modules/archiva-base/archiva-consumers/archiva-core-consumers/src/test/java/org/apache/archiva/consumers/core/repository/CleanupReleasedSnapshotsRepositoryPurgeTest.java
index 76b6ce72d..8e497dc2c 100644
--- a/archiva-modules/archiva-base/archiva-consumers/archiva-core-consumers/src/test/java/org/apache/archiva/consumers/core/repository/CleanupReleasedSnapshotsRepositoryPurgeTest.java
+++ b/archiva-modules/archiva-base/archiva-consumers/archiva-core-consumers/src/test/java/org/apache/archiva/consumers/core/repository/CleanupReleasedSnapshotsRepositoryPurgeTest.java
@@ -74,6 +74,8 @@ public class CleanupReleasedSnapshotsRepositoryPurgeTest
     @Inject
     MetadataTools metadataTools;
 
+
+
     @Before
     @Override
     public void setUp()
diff --git a/archiva-modules/archiva-base/archiva-consumers/archiva-indexer-consumers/src/test/java/org/apache/archiva/consumers/lucene/NexusIndexerConsumerTest.java b/archiva-modules/archiva-base/archiva-consumers/archiva-indexer-consumers/src/test/java/org/apache/archiva/consumers/lucene/NexusIndexerConsumerTest.java
index 85ee9426d..241eeb09b 100644
--- a/archiva-modules/archiva-base/archiva-consumers/archiva-indexer-consumers/src/test/java/org/apache/archiva/consumers/lucene/NexusIndexerConsumerTest.java
+++ b/archiva-modules/archiva-base/archiva-consumers/archiva-indexer-consumers/src/test/java/org/apache/archiva/consumers/lucene/NexusIndexerConsumerTest.java
@@ -27,6 +27,7 @@ import org.apache.archiva.components.taskqueue.TaskQueueException;
 import org.apache.archiva.repository.base.ArchivaRepositoryRegistry;
 import org.apache.archiva.repository.base.BasicManagedRepository;
 import org.apache.archiva.repository.ReleaseScheme;
+import org.apache.archiva.repository.base.RepositoryGroupHandler;
 import org.apache.archiva.scheduler.ArchivaTaskScheduler;
 import org.apache.archiva.scheduler.indexing.ArtifactIndexingTask;
 import org.apache.archiva.test.utils.ArchivaSpringJUnit4ClassRunner;
@@ -96,6 +97,9 @@ public class NexusIndexerConsumerTest
     @Inject
     ArchivaRepositoryRegistry repositoryRegistry;
 
+    @SuppressWarnings( "unused" )
+    @Inject
+    RepositoryGroupHandler repositoryGroupHandler;
 
     @Override
     @Before
diff --git a/archiva-modules/archiva-base/archiva-repository-admin/archiva-repository-admin-default/src/main/java/org/apache/archiva/admin/repository/group/DefaultRepositoryGroupAdmin.java b/archiva-modules/archiva-base/archiva-repository-admin/archiva-repository-admin-default/src/main/java/org/apache/archiva/admin/repository/group/DefaultRepositoryGroupAdmin.java
index ae6c4fd3b..13f3ce6f9 100644
--- a/archiva-modules/archiva-base/archiva-repository-admin/archiva-repository-admin-default/src/main/java/org/apache/archiva/admin/repository/group/DefaultRepositoryGroupAdmin.java
+++ b/archiva-modules/archiva-base/archiva-repository-admin/archiva-repository-admin-default/src/main/java/org/apache/archiva/admin/repository/group/DefaultRepositoryGroupAdmin.java
@@ -29,11 +29,15 @@ import org.apache.archiva.admin.model.managed.ManagedRepositoryAdmin;
 import org.apache.archiva.admin.repository.AbstractRepositoryAdmin;
 import org.apache.archiva.configuration.Configuration;
 import org.apache.archiva.configuration.RepositoryGroupConfiguration;
+import org.apache.archiva.event.Event;
+import org.apache.archiva.event.EventHandler;
+import org.apache.archiva.event.EventType;
 import org.apache.archiva.metadata.model.facets.AuditEvent;
 import org.apache.archiva.indexer.merger.MergedRemoteIndexesScheduler;
 import org.apache.archiva.repository.EditableRepositoryGroup;
 import org.apache.archiva.repository.RepositoryException;
 import org.apache.archiva.repository.RepositoryRegistry;
+import org.apache.archiva.repository.event.RepositoryRegistryEvent;
 import org.apache.archiva.repository.features.IndexCreationFeature;
 import org.apache.archiva.repository.storage.StorageAsset;
 import org.apache.commons.lang3.StringUtils;
@@ -62,7 +66,7 @@ import java.util.stream.Collectors;
 @Service("repositoryGroupAdmin#default")
 public class DefaultRepositoryGroupAdmin
     extends AbstractRepositoryAdmin
-    implements RepositoryGroupAdmin
+    implements RepositoryGroupAdmin, EventHandler<Event>
 {
 
     private Logger log = LoggerFactory.getLogger( getClass() );
@@ -82,6 +86,10 @@ public class DefaultRepositoryGroupAdmin
     private Path groupsDirectory;
 
     @PostConstruct
+    public void baseInit() {
+        this.repositoryRegistry.registerEventHandler( EventType.ROOT, this );
+    }
+
     public void initialize()
     {
         String appServerBase = getRegistry().getString( "appserver.base" );
@@ -438,4 +446,14 @@ public class DefaultRepositoryGroupAdmin
         rg.setLocation( group.getLocation().toString() );
         return rg;
     }
+
+    @Override
+    public void handle( Event event )
+    {
+        if ( EventType.isInstanceOf( event.getType( ), RepositoryRegistryEvent.INITIALIZED ) )
+        {
+            log.debug( "Initializing RepositoryGroupAdmin" );
+            initialize();
+        }
+    }
 }
diff --git a/archiva-modules/archiva-base/archiva-repository-admin/archiva-repository-admin-default/src/test/java/org/apache/archiva/admin/repository/AbstractRepositoryAdminTest.java b/archiva-modules/archiva-base/archiva-repository-admin/archiva-repository-admin-default/src/test/java/org/apache/archiva/admin/repository/AbstractRepositoryAdminTest.java
index d3086e2f7..993151a83 100644
--- a/archiva-modules/archiva-base/archiva-repository-admin/archiva-repository-admin-default/src/test/java/org/apache/archiva/admin/repository/AbstractRepositoryAdminTest.java
+++ b/archiva-modules/archiva-base/archiva-repository-admin/archiva-repository-admin-default/src/test/java/org/apache/archiva/admin/repository/AbstractRepositoryAdminTest.java
@@ -31,6 +31,7 @@ import org.apache.archiva.configuration.ArchivaConfiguration;
 import org.apache.archiva.redback.role.RoleManager;
 import org.apache.archiva.redback.users.User;
 import org.apache.archiva.redback.users.memory.SimpleUser;
+import org.apache.archiva.repository.base.RepositoryGroupHandler;
 import org.apache.archiva.test.utils.ArchivaSpringJUnit4ClassRunner;
 import org.apache.commons.lang3.StringUtils;
 import org.junit.Before;
@@ -84,6 +85,10 @@ public abstract class AbstractRepositoryAdminTest
     @Inject
     private ArchivaConfiguration archivaConfiguration;
 
+    @SuppressWarnings( "unused" )
+    @Inject
+    RepositoryGroupHandler repositoryGroupHandler;
+
     @Before
     public void initialize() {
         Path confFile = Paths.get(APPSERVER_BASE_PATH, "conf/archiva.xml");
diff --git a/archiva-modules/archiva-base/archiva-repository-admin/archiva-repository-admin-default/src/test/java/org/apache/archiva/admin/repository/group/RepositoryGroupAdminTest.java b/archiva-modules/archiva-base/archiva-repository-admin/archiva-repository-admin-default/src/test/java/org/apache/archiva/admin/repository/group/RepositoryGroupAdminTest.java
index ed6e28683..49fd38573 100644
--- a/archiva-modules/archiva-base/archiva-repository-admin/archiva-repository-admin-default/src/test/java/org/apache/archiva/admin/repository/group/RepositoryGroupAdminTest.java
+++ b/archiva-modules/archiva-base/archiva-repository-admin/archiva-repository-admin-default/src/test/java/org/apache/archiva/admin/repository/group/RepositoryGroupAdminTest.java
@@ -26,6 +26,7 @@ import org.apache.archiva.admin.repository.AbstractRepositoryAdminTest;
 import org.apache.archiva.metadata.model.facets.AuditEvent;
 import org.apache.archiva.repository.Repository;
 import org.apache.archiva.repository.RepositoryRegistry;
+import org.apache.archiva.repository.base.RepositoryGroupHandler;
 import org.junit.Test;
 
 import javax.inject.Inject;
@@ -44,6 +45,9 @@ public class RepositoryGroupAdminTest
     @Inject
     RepositoryRegistry repositoryRegistry;
 
+    @Inject
+    RepositoryGroupHandler repositoryGroupHandler;
+
     @Test
     public void addAndDeleteGroup()
         throws Exception
diff --git a/archiva-modules/archiva-base/archiva-repository-api/src/main/java/org/apache/archiva/repository/event/RepositoryRegistryEvent.java b/archiva-modules/archiva-base/archiva-repository-api/src/main/java/org/apache/archiva/repository/event/RepositoryRegistryEvent.java
index 1e1157959..7f3b62ddc 100644
--- a/archiva-modules/archiva-base/archiva-repository-api/src/main/java/org/apache/archiva/repository/event/RepositoryRegistryEvent.java
+++ b/archiva-modules/archiva-base/archiva-repository-api/src/main/java/org/apache/archiva/repository/event/RepositoryRegistryEvent.java
@@ -47,6 +47,21 @@ public class RepositoryRegistryEvent extends Event
      */
     public static EventType<RepositoryRegistryEvent> INITIALIZED = new EventType(ANY, "REGISTRY.INITIALIZED");
 
+    /**
+     * When the repository groups are initialized
+     */
+    public static EventType<RepositoryRegistryEvent> GROUPS_INITIALIZED = new EventType(ANY, "REGISTRY.GROUPS_INITIALIZED");
+
+    /**
+     * When the managed repositories are initialized
+     */
+    public static EventType<RepositoryRegistryEvent> MANAGED_REPOS_INITIALIZED = new EventType(ANY, "REGISTRY.MANAGED_REPOS_INITIALIZED");
+
+    /**
+     * When the remote repositories are initialized
+     */
+    public static EventType<RepositoryRegistryEvent> REMOTE_REPOS_INITIALIZED = new EventType(ANY, "REGISTRY.REMOTE_REPOS_INITIALIZED");
+
     public RepositoryRegistryEvent(EventType<? extends RepositoryRegistryEvent> type, Object origin) {
         super(type, origin);
     }
diff --git a/archiva-modules/archiva-base/archiva-repository-layer/src/main/java/org/apache/archiva/repository/base/ArchivaRepositoryRegistry.java b/archiva-modules/archiva-base/archiva-repository-layer/src/main/java/org/apache/archiva/repository/base/ArchivaRepositoryRegistry.java
index b909e24de..6a3d0e0b3 100644
--- a/archiva-modules/archiva-base/archiva-repository-layer/src/main/java/org/apache/archiva/repository/base/ArchivaRepositoryRegistry.java
+++ b/archiva-modules/archiva-base/archiva-repository-layer/src/main/java/org/apache/archiva/repository/base/ArchivaRepositoryRegistry.java
@@ -28,7 +28,6 @@ import org.apache.archiva.components.registry.RegistryException;
 import org.apache.archiva.repository.EditableManagedRepository;
 import org.apache.archiva.repository.EditableRemoteRepository;
 import org.apache.archiva.repository.EditableRepository;
-import org.apache.archiva.repository.EditableRepositoryGroup;
 import org.apache.archiva.repository.ManagedRepository;
 import org.apache.archiva.repository.RemoteRepository;
 import org.apache.archiva.repository.Repository;
@@ -55,12 +54,11 @@ import javax.annotation.PreDestroy;
 import javax.inject.Inject;
 import javax.inject.Named;
 import java.util.*;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.locks.ReentrantReadWriteLock;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
-import static org.apache.archiva.indexer.ArchivaIndexManager.DEFAULT_INDEX_PATH;
-
 /**
  * Registry for repositories. This is the central entry point for repositories. It provides methods for
  * retrieving, adding and removing repositories.
@@ -78,6 +76,7 @@ public class ArchivaRepositoryRegistry implements ConfigurationListener, EventHa
 {
 
     private static final Logger log = LoggerFactory.getLogger(RepositoryRegistry.class);
+    private final ConfigurationHandler configurationHandler;
 
     /**
      * We inject all repository providers
@@ -89,15 +88,14 @@ public class ArchivaRepositoryRegistry implements ConfigurationListener, EventHa
     IndexManagerFactory indexManagerFactory;
 
     @Inject
-    ArchivaConfiguration archivaConfiguration;
-
-    @Inject
     List<MetadataReader> metadataReaderList;
 
     @Inject
     @Named("repositoryContentFactory#default")
     RepositoryContentFactory repositoryContentFactory;
 
+
+
     private final EventManager eventManager;
 
 
@@ -107,20 +105,23 @@ public class ArchivaRepositoryRegistry implements ConfigurationListener, EventHa
     private Map<String, RemoteRepository> remoteRepositories = new HashMap<>();
     private Map<String, RemoteRepository> uRemoteRepositories = Collections.unmodifiableMap(remoteRepositories);
 
-    private Map<String, RepositoryGroup> repositoryGroups = new HashMap<>();
-    private Map<String, RepositoryGroup> uRepositoryGroups = Collections.unmodifiableMap(repositoryGroups);
-
     private ReentrantReadWriteLock rwLock = new ReentrantReadWriteLock();
 
-    private volatile boolean ignoreConfigEvents = false;
+    private RepositoryGroupHandler groupHandler;
 
-    public ArchivaRepositoryRegistry() {
+    private AtomicBoolean groups_initalized = new AtomicBoolean( false );
+    private AtomicBoolean managed_initialized = new AtomicBoolean( false );
+    private AtomicBoolean remote_initialized = new AtomicBoolean( false );
+
+
+    public ArchivaRepositoryRegistry(ConfigurationHandler configurationHandler) {
         this.eventManager = new EventManager(this);
+        this.configurationHandler = configurationHandler;
     }
 
     @Override
     public void setArchivaConfiguration( ArchivaConfiguration archivaConfiguration ) {
-        this.archivaConfiguration = archivaConfiguration;
+        this.configurationHandler.setArchivaConfiguration( archivaConfiguration );
     }
 
     @PostConstruct
@@ -128,21 +129,41 @@ public class ArchivaRepositoryRegistry implements ConfigurationListener, EventHa
         rwLock.writeLock().lock();
         try {
             log.debug("Initializing repository registry");
-            updateManagedRepositoriesFromConfig();
-            updateRemoteRepositoriesFromConfig();
-
-            repositoryGroups.clear();
-            Map<String, RepositoryGroup> repositoryGroups = getRepositorGroupsFromConfig();
-            this.repositoryGroups.putAll(repositoryGroups);
-
-            // archivaConfiguration.addChangeListener(this);
-            archivaConfiguration.addListener(this);
+            updateManagedRepositoriesFromConfig( );
+            pushEvent( new RepositoryRegistryEvent( RepositoryRegistryEvent.MANAGED_REPOS_INITIALIZED, this ) );
+            managed_initialized.set( true );
+            updateRemoteRepositoriesFromConfig( );
+            pushEvent( new RepositoryRegistryEvent( RepositoryRegistryEvent.REMOTE_REPOS_INITIALIZED, this ) );
+            remote_initialized.set( true );
+
+            initializeRepositoryGroups();
+            this.configurationHandler.addListener(this);
         } finally {
             rwLock.writeLock().unlock();
         }
         pushEvent(new RepositoryRegistryEvent(RepositoryRegistryEvent.RELOADED, this));
+        if (managed_initialized.get() && remote_initialized.get() && groups_initalized.get( )) {
+            pushEvent( new RepositoryRegistryEvent( RepositoryRegistryEvent.INITIALIZED, this ) );
+        }
     }
 
+    private void initializeRepositoryGroups() {
+        if (this.groupHandler!=null) {
+            this.groupHandler.initializeFromConfig();
+            this.groups_initalized.set( true );
+            pushEvent( new RepositoryRegistryEvent( RepositoryRegistryEvent.GROUPS_INITIALIZED, this ) );
+        }
+    }
+
+    public void registerGroupHandler(RepositoryGroupHandler groupHandler) {
+        this.groupHandler = groupHandler;
+        initializeRepositoryGroups();
+        if (managed_initialized.get() && remote_initialized.get() && groups_initalized.get( )) {
+            pushEvent( new RepositoryRegistryEvent( RepositoryRegistryEvent.INITIALIZED, this ) );
+        }
+    }
+
+
     @PreDestroy
     public void destroy() {
         for (ManagedRepository rep : managedRepositories.values()) {
@@ -153,11 +174,12 @@ public class ArchivaRepositoryRegistry implements ConfigurationListener, EventHa
             repo.close();
         }
         remoteRepositories.clear();
+        groupHandler.close();
         pushEvent(new RepositoryRegistryEvent(RepositoryRegistryEvent.DESTROYED, this));
     }
 
 
-    private Map<RepositoryType, RepositoryProvider> createProviderMap() {
+    protected Map<RepositoryType, RepositoryProvider> getRepositoryProviderMap() {
         Map<RepositoryType, RepositoryProvider> map = new HashMap<>();
         if (repositoryProviders != null) {
             for (RepositoryProvider provider : repositoryProviders) {
@@ -169,7 +191,7 @@ public class ArchivaRepositoryRegistry implements ConfigurationListener, EventHa
         return map;
     }
 
-    private RepositoryProvider getProvider(RepositoryType type) throws RepositoryException
+    protected RepositoryProvider getProvider(RepositoryType type) throws RepositoryException
     {
         return repositoryProviders.stream().filter(repositoryProvider -> repositoryProvider.provides().contains(type)).findFirst().orElseThrow(() -> new RepositoryException("Repository type cannot be handled: " + type));
     }
@@ -182,7 +204,7 @@ public class ArchivaRepositoryRegistry implements ConfigurationListener, EventHa
 
             Set<String> configRepoIds = new HashSet<>();
             List<ManagedRepositoryConfiguration> managedRepoConfigs =
-                    getArchivaConfiguration().getConfiguration().getManagedRepositories();
+                    configurationHandler.getBaseConfiguration().getManagedRepositories();
 
             if (managedRepoConfigs == null) {
                 return;
@@ -299,7 +321,7 @@ public class ArchivaRepositoryRegistry implements ConfigurationListener, EventHa
     private void updateRemoteRepositoriesFromConfig() {
         try {
             List<RemoteRepositoryConfiguration> remoteRepoConfigs =
-                    getArchivaConfiguration().getConfiguration().getRemoteRepositories();
+                    configurationHandler.getBaseConfiguration().getRemoteRepositories();
 
             if (remoteRepoConfigs == null) {
                 return;
@@ -341,53 +363,8 @@ public class ArchivaRepositoryRegistry implements ConfigurationListener, EventHa
         repo.registerEventHandler(RepositoryEvent.ANY, this);
     }
 
-    private Map<String, RepositoryGroup> getRepositorGroupsFromConfig() {
-        try {
-            List<RepositoryGroupConfiguration> repositoryGroupConfigurations =
-                    getArchivaConfiguration().getConfiguration().getRepositoryGroups();
-
-            if (repositoryGroupConfigurations == null) {
-                return Collections.emptyMap();
-            }
-
-            Map<String, RepositoryGroup> repositoryGroupMap = new LinkedHashMap<>(repositoryGroupConfigurations.size());
-
-            Map<RepositoryType, RepositoryProvider> providerMap = createProviderMap();
-            for (RepositoryGroupConfiguration repoConfig : repositoryGroupConfigurations) {
-                RepositoryType repositoryType = RepositoryType.valueOf(repoConfig.getType());
-                if (providerMap.containsKey(repositoryType)) {
-                    try {
-                        RepositoryGroup repo = createNewRepositoryGroup(providerMap.get(repositoryType), repoConfig);
-                        repositoryGroupMap.put(repo.getId(), repo);
-                    } catch (Exception e) {
-                        log.error("Could not create repository group {}: {}", repoConfig.getId(), e.getMessage(), e);
-                    }
-                }
-            }
-            return repositoryGroupMap;
-        } catch (Throwable e) {
-            log.error("Could not initialize repositories from config: {}", e.getMessage(), e);
-            return Collections.emptyMap();
-        }
-    }
-
-    private RepositoryGroup createNewRepositoryGroup(RepositoryProvider provider, RepositoryGroupConfiguration config) throws RepositoryException {
-        RepositoryGroup repositoryGroup = provider.createRepositoryGroup(config);
-        repositoryGroup.registerEventHandler(RepositoryEvent.ANY, this);
-        updateRepositoryReferences(provider, repositoryGroup, config);
-        return repositoryGroup;
-    }
 
-    private void updateRepositoryReferences(RepositoryProvider provider, RepositoryGroup group, RepositoryGroupConfiguration configuration) {
-        if (group instanceof EditableRepositoryGroup ) {
-            EditableRepositoryGroup eGroup = (EditableRepositoryGroup) group;
-            eGroup.setRepositories(configuration.getRepositories().stream().map(r -> getManagedRepository(r)).collect(Collectors.toList()));
-        }
-    }
 
-    private ArchivaConfiguration getArchivaConfiguration() {
-        return this.archivaConfiguration;
-    }
 
     /**
      * Returns all repositories that are registered. There is no defined order of the returned repositories.
@@ -438,7 +415,7 @@ public class ArchivaRepositoryRegistry implements ConfigurationListener, EventHa
     public Collection<RepositoryGroup> getRepositoryGroups( ) {
         rwLock.readLock().lock();
         try {
-            return uRepositoryGroups.values();
+            return groupHandler.getRepositoryGroups( );
         } finally {
             rwLock.readLock().unlock();
         }
@@ -462,8 +439,8 @@ public class ArchivaRepositoryRegistry implements ConfigurationListener, EventHa
             } else if (remoteRepositories.containsKey(repoId)) {
                 log.debug("Remote repo");
                 return remoteRepositories.get(repoId);
-            } else if (repositoryGroups.containsKey(repoId)) {
-                return repositoryGroups.get(repoId);
+            } else if (groupHandler.hasRepositoryGroup(repoId)) {
+                return groupHandler.getRepositoryGroup(repoId);
             } else {
                 return null;
             }
@@ -510,23 +487,14 @@ public class ArchivaRepositoryRegistry implements ConfigurationListener, EventHa
     public RepositoryGroup getRepositoryGroup( String groupId ) {
         rwLock.readLock().lock();
         try {
-            return repositoryGroups.get(groupId);
+            return groupHandler.getRepositoryGroup(groupId);
         } finally {
             rwLock.readLock().unlock();
         }
     }
 
-    /*
-     * The <code>ignoreConfigEvents</code> works only for synchronized configuration events.
-     * If the configuration throws async events, we cannot know, if the event is caused by this instance or another thread.
-     */
-    private void saveConfiguration(Configuration configuration) throws IndeterminateConfigurationException, RegistryException {
-        ignoreConfigEvents = true;
-        try {
-            getArchivaConfiguration().save(configuration);
-        } finally {
-            ignoreConfigEvents = false;
-        }
+    protected void saveConfiguration(Configuration configuration) throws IndeterminateConfigurationException, RegistryException {
+        configurationHandler.save(configuration, ConfigurationHandler.REGISTRY_EVENT_TAG );
     }
 
     /**
@@ -552,7 +520,7 @@ public class ArchivaRepositoryRegistry implements ConfigurationListener, EventHa
                 }
                 RepositoryProvider provider = getProvider(managedRepository.getType());
                 ManagedRepositoryConfiguration newCfg = provider.getManagedConfiguration(managedRepository);
-                Configuration configuration = getArchivaConfiguration().getConfiguration();
+                Configuration configuration = configurationHandler.getBaseConfiguration();
                 updateRepositoryReferences(provider, managedRepository, newCfg, configuration);
                 ManagedRepositoryConfiguration oldCfg = configuration.findManagedRepositoryById(id);
                 if (oldCfg != null) {
@@ -595,7 +563,7 @@ public class ArchivaRepositoryRegistry implements ConfigurationListener, EventHa
         try {
             final String id = managedRepositoryConfiguration.getId();
             final RepositoryType repositoryType = RepositoryType.valueOf(managedRepositoryConfiguration.getType());
-            Configuration configuration = getArchivaConfiguration().getConfiguration();
+            Configuration configuration = configurationHandler.getBaseConfiguration();
             ManagedRepository repo = managedRepositories.get(id);
             ManagedRepositoryConfiguration oldCfg = repo != null ? getProvider(repositoryType).getManagedConfiguration(repo) : null;
             repo = putRepository(managedRepositoryConfiguration, configuration);
@@ -670,33 +638,10 @@ public class ArchivaRepositoryRegistry implements ConfigurationListener, EventHa
     public RepositoryGroup putRepositoryGroup( RepositoryGroup repositoryGroup ) throws RepositoryException {
         rwLock.writeLock().lock();
         try {
-            final String id = repositoryGroup.getId();
-            RepositoryGroup originRepoGroup = repositoryGroups.put(id, repositoryGroup);
-            try {
-                if (originRepoGroup != null && originRepoGroup != repositoryGroup) {
-                    originRepoGroup.close();
-                }
-                RepositoryProvider provider = getProvider(repositoryGroup.getType());
-                RepositoryGroupConfiguration newCfg = provider.getRepositoryGroupConfiguration(repositoryGroup);
-                Configuration configuration = getArchivaConfiguration().getConfiguration();
-                updateRepositoryReferences(provider, repositoryGroup, newCfg);
-                RepositoryGroupConfiguration oldCfg = configuration.findRepositoryGroupById(id);
-                if (oldCfg != null) {
-                    configuration.removeRepositoryGroup(oldCfg);
-                }
-                configuration.addRepositoryGroup(newCfg);
-                saveConfiguration(configuration);
-                return repositoryGroup;
-            } catch (Exception e) {
-                // Rollback
-                if (originRepoGroup != null) {
-                    repositoryGroups.put(id, originRepoGroup);
-                } else {
-                    repositoryGroups.remove(id);
-                }
-                log.error("Exception during configuration update {}", e.getMessage(), e);
-                throw new RepositoryException("Could not save the configuration" + (e.getMessage() == null ? "" : ": " + e.getMessage()));
+            if (this.groupHandler==null) {
+                throw new RepositoryException( "Fatal error. RepositoryGroupHandler not registered!" );
             }
+            return this.groupHandler.putRepositoryGroup( repositoryGroup );
         } finally {
             rwLock.writeLock().unlock();
         }
@@ -714,22 +659,7 @@ public class ArchivaRepositoryRegistry implements ConfigurationListener, EventHa
     public RepositoryGroup putRepositoryGroup( RepositoryGroupConfiguration repositoryGroupConfiguration ) throws RepositoryException {
         rwLock.writeLock().lock();
         try {
-            final String id = repositoryGroupConfiguration.getId();
-            final RepositoryType repositoryType = RepositoryType.valueOf(repositoryGroupConfiguration.getType());
-            Configuration configuration = getArchivaConfiguration().getConfiguration();
-            RepositoryGroup repo = repositoryGroups.get(id);
-            RepositoryGroupConfiguration oldCfg = repo != null ? getProvider(repositoryType).getRepositoryGroupConfiguration(repo) : null;
-            repo = putRepositoryGroup(repositoryGroupConfiguration, configuration);
-            try {
-                saveConfiguration(configuration);
-            } catch (IndeterminateConfigurationException | RegistryException e) {
-                if (oldCfg != null) {
-                    getProvider(repositoryType).updateRepositoryGroupInstance((EditableRepositoryGroup) repo, oldCfg);
-                }
-                log.error("Could not save the configuration for repository group {}: {}", id, e.getMessage(), e);
-                throw new RepositoryException("Could not save the configuration for repository group " + id + ": " + e.getMessage());
-            }
-            return repo;
+            return groupHandler.putRepositoryGroup( repositoryGroupConfiguration );
         } finally {
             rwLock.writeLock().unlock();
         }
@@ -749,41 +679,12 @@ public class ArchivaRepositoryRegistry implements ConfigurationListener, EventHa
     public RepositoryGroup putRepositoryGroup( RepositoryGroupConfiguration repositoryGroupConfiguration, Configuration configuration ) throws RepositoryException {
         rwLock.writeLock().lock();
         try {
-            final String id = repositoryGroupConfiguration.getId();
-            final RepositoryType repoType = RepositoryType.valueOf(repositoryGroupConfiguration.getType());
-            RepositoryGroup repo;
-            setRepositoryGroupDefaults(repositoryGroupConfiguration);
-            if (repositoryGroups.containsKey(id)) {
-                repo = repositoryGroups.get(id);
-                if (repo instanceof EditableRepositoryGroup) {
-                    getProvider(repoType).updateRepositoryGroupInstance((EditableRepositoryGroup) repo, repositoryGroupConfiguration);
-                } else {
-                    throw new RepositoryException("The repository is not editable " + id);
-                }
-            } else {
-                repo = getProvider(repoType).createRepositoryGroup(repositoryGroupConfiguration);
-                repositoryGroups.put(id, repo);
-            }
-            updateRepositoryReferences(getProvider(repoType), repo, repositoryGroupConfiguration);
-            replaceOrAddRepositoryConfig(repositoryGroupConfiguration, configuration);
-            return repo;
+            return groupHandler.putRepositoryGroup( repositoryGroupConfiguration, configuration );
         } finally {
             rwLock.writeLock().unlock();
         }
     }
 
-    private void setRepositoryGroupDefaults(RepositoryGroupConfiguration repositoryGroupConfiguration) {
-        if (StringUtils.isEmpty(repositoryGroupConfiguration.getMergedIndexPath())) {
-            repositoryGroupConfiguration.setMergedIndexPath(DEFAULT_INDEX_PATH);
-        }
-        if (repositoryGroupConfiguration.getMergedIndexTtl() <= 0) {
-            repositoryGroupConfiguration.setMergedIndexTtl(300);
-        }
-        if (StringUtils.isEmpty(repositoryGroupConfiguration.getCronExpression())) {
-            repositoryGroupConfiguration.setCronExpression("0 0 03 ? * MON");
-        }
-    }
-
     private void replaceOrAddRepositoryConfig(ManagedRepositoryConfiguration managedRepositoryConfiguration, Configuration configuration) {
         if (configuration != null) {
             ManagedRepositoryConfiguration oldCfg = configuration.findManagedRepositoryById(managedRepositoryConfiguration.getId());
@@ -874,7 +775,7 @@ public class ArchivaRepositoryRegistry implements ConfigurationListener, EventHa
     public RemoteRepository putRepository( RemoteRepository remoteRepository ) throws RepositoryException {
         rwLock.writeLock().lock();
         try {
-            Configuration configuration = getArchivaConfiguration().getConfiguration();
+            Configuration configuration = configurationHandler.getBaseConfiguration();
             try {
                 RemoteRepository repo = putRepository(remoteRepository, configuration);
                 saveConfiguration(configuration);
@@ -902,7 +803,7 @@ public class ArchivaRepositoryRegistry implements ConfigurationListener, EventHa
         try {
             final String id = remoteRepositoryConfiguration.getId();
             final RepositoryType repositoryType = RepositoryType.valueOf(remoteRepositoryConfiguration.getType());
-            Configuration configuration = getArchivaConfiguration().getConfiguration();
+            Configuration configuration = configurationHandler.getBaseConfiguration();
             RemoteRepository repo = remoteRepositories.get(id);
             RemoteRepositoryConfiguration oldCfg = repo != null ? getProvider(repositoryType).getRemoteConfiguration(repo) : null;
             repo = putRepository(remoteRepositoryConfiguration, configuration);
@@ -1012,8 +913,8 @@ public class ArchivaRepositoryRegistry implements ConfigurationListener, EventHa
                 repo = managedRepositories.remove(id);
                 if (repo != null) {
                     repo.close();
-                    removeRepositoryFromGroups(repo);
-                    Configuration configuration = getArchivaConfiguration().getConfiguration();
+                    this.groupHandler.removeRepositoryFromGroups(repo);
+                    Configuration configuration = configurationHandler.getBaseConfiguration();
                     ManagedRepositoryConfiguration cfg = configuration.findManagedRepositoryById(id);
                     if (cfg != null) {
                         configuration.removeManagedRepository(cfg);
@@ -1032,12 +933,6 @@ public class ArchivaRepositoryRegistry implements ConfigurationListener, EventHa
         }
     }
 
-    private void removeRepositoryFromGroups(ManagedRepository repo) {
-        if (repo != null) {
-            repositoryGroups.values().stream().filter(repoGroup -> repoGroup instanceof EditableRepository).
-                    map(repoGroup -> (EditableRepositoryGroup) repoGroup).forEach(repoGroup -> repoGroup.removeRepository(repo));
-        }
-    }
 
     @Override
     public void removeRepository( ManagedRepository managedRepository, Configuration configuration ) throws RepositoryException {
@@ -1052,7 +947,7 @@ public class ArchivaRepositoryRegistry implements ConfigurationListener, EventHa
                 repo = managedRepositories.remove(id);
                 if (repo != null) {
                     repo.close();
-                    removeRepositoryFromGroups(repo);
+                    this.groupHandler.removeRepositoryFromGroups(repo);
                     ManagedRepositoryConfiguration cfg = configuration.findManagedRepositoryById(id);
                     if (cfg != null) {
                         configuration.removeManagedRepository(cfg);
@@ -1080,26 +975,10 @@ public class ArchivaRepositoryRegistry implements ConfigurationListener, EventHa
             return;
         }
         final String id = repositoryGroup.getId();
-        RepositoryGroup repo = getRepositoryGroup(id);
-        if (repo != null) {
+        if (groupHandler.hasRepositoryGroup( id )) {
             rwLock.writeLock().lock();
             try {
-                repo = repositoryGroups.remove(id);
-                if (repo != null) {
-                    repo.close();
-                    Configuration configuration = getArchivaConfiguration().getConfiguration();
-                    RepositoryGroupConfiguration cfg = configuration.findRepositoryGroupById(id);
-                    if (cfg != null) {
-                        configuration.removeRepositoryGroup(cfg);
-                    }
-                    saveConfiguration(configuration);
-                }
-
-            } catch (RegistryException | IndeterminateConfigurationException e) {
-                // Rollback
-                log.error("Could not save config after repository removal: {}", e.getMessage(), e);
-                repositoryGroups.put(repo.getId(), repo);
-                throw new RepositoryException("Could not save configuration after repository removal: " + e.getMessage());
+            groupHandler.removeRepositoryGroup( id );
             } finally {
                 rwLock.writeLock().unlock();
             }
@@ -1112,23 +991,14 @@ public class ArchivaRepositoryRegistry implements ConfigurationListener, EventHa
             return;
         }
         final String id = repositoryGroup.getId();
-        RepositoryGroup repo = getRepositoryGroup(id);
-        if (repo != null) {
+        if (groupHandler.hasRepositoryGroup( id )) {
             rwLock.writeLock().lock();
             try {
-                repo = repositoryGroups.remove(id);
-                if (repo != null) {
-                    repo.close();
-                    RepositoryGroupConfiguration cfg = configuration.findRepositoryGroupById(id);
-                    if (cfg != null) {
-                        configuration.removeRepositoryGroup(cfg);
-                    }
-                }
+                groupHandler.removeRepositoryGroup( id, configuration );
             } finally {
                 rwLock.writeLock().unlock();
             }
         }
-
     }
 
     private void doRemoveRepo(RemoteRepository repo, Configuration configuration) {
@@ -1164,7 +1034,7 @@ public class ArchivaRepositoryRegistry implements ConfigurationListener, EventHa
             try {
                 repo = remoteRepositories.remove(id);
                 if (repo != null) {
-                    Configuration configuration = getArchivaConfiguration().getConfiguration();
+                    Configuration configuration = configurationHandler.getBaseConfiguration();
                     doRemoveRepo(repo, configuration);
                     saveConfiguration(configuration);
                 }
@@ -1292,8 +1162,9 @@ public class ArchivaRepositoryRegistry implements ConfigurationListener, EventHa
 
     @Override
     public void configurationEvent(ConfigurationEvent event) {
-        // Note: the ignoreConfigEvents flag does not work, if the config events are asynchronous.
-        if (!ignoreConfigEvents) {
+        // We ignore the event, if the save was triggered by ourself
+        if ( !ConfigurationHandler.REGISTRY_EVENT_TAG.equals( event.getTag( ) ) )
+        {
             reload();
         }
     }
diff --git a/archiva-modules/archiva-base/archiva-repository-layer/src/main/java/org/apache/archiva/repository/base/ConfigurationHandler.java b/archiva-modules/archiva-base/archiva-repository-layer/src/main/java/org/apache/archiva/repository/base/ConfigurationHandler.java
new file mode 100644
index 000000000..c4ee51370
--- /dev/null
+++ b/archiva-modules/archiva-base/archiva-repository-layer/src/main/java/org/apache/archiva/repository/base/ConfigurationHandler.java
@@ -0,0 +1,71 @@
+package org.apache.archiva.repository.base;
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import org.apache.archiva.components.registry.RegistryException;
+import org.apache.archiva.configuration.ArchivaConfiguration;
+import org.apache.archiva.configuration.Configuration;
+import org.apache.archiva.configuration.ConfigurationListener;
+import org.apache.archiva.configuration.IndeterminateConfigurationException;
+import org.springframework.stereotype.Service;
+
+/**
+ * This is just a simple wrapper to access the archiva configuration used by the registry and associated classes
+ *
+ * @author Martin Stockhammer <martin_s@apache.org>
+ */
+@Service("configurationHandler#default")
+public class ConfigurationHandler
+{
+    public static final String REGISTRY_EVENT_TAG = "repositoryRegistry";
+
+    private ArchivaConfiguration archivaConfiguration;
+
+    public ConfigurationHandler( ArchivaConfiguration archivaConfiguration ) {
+        this.archivaConfiguration = archivaConfiguration;
+    }
+
+    public void addListener( ConfigurationListener listener ) {
+        this.archivaConfiguration.addListener( listener );
+    }
+
+    public ArchivaConfiguration getArchivaConfiguration( )
+    {
+        return archivaConfiguration;
+    }
+
+    public void setArchivaConfiguration( ArchivaConfiguration archivaConfiguration )
+    {
+        this.archivaConfiguration = archivaConfiguration;
+    }
+
+    public Configuration getBaseConfiguration() {
+        return archivaConfiguration.getConfiguration( );
+    }
+
+    public void save(Configuration configuration, String eventTag) throws IndeterminateConfigurationException, RegistryException
+    {
+        archivaConfiguration.save( configuration, eventTag);
+    }
+
+    public void save(Configuration configuration) throws IndeterminateConfigurationException, RegistryException
+    {
+        archivaConfiguration.save( configuration, "" );
+    }
+
+}
diff --git a/archiva-modules/archiva-base/archiva-repository-layer/src/main/java/org/apache/archiva/repository/base/RepositoryGroupHandler.java b/archiva-modules/archiva-base/archiva-repository-layer/src/main/java/org/apache/archiva/repository/base/RepositoryGroupHandler.java
new file mode 100644
index 000000000..f4b02a2d6
--- /dev/null
+++ b/archiva-modules/archiva-base/archiva-repository-layer/src/main/java/org/apache/archiva/repository/base/RepositoryGroupHandler.java
@@ -0,0 +1,328 @@
+package org.apache.archiva.repository.base;
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import org.apache.archiva.components.registry.RegistryException;
+import org.apache.archiva.configuration.Configuration;
+import org.apache.archiva.configuration.IndeterminateConfigurationException;
+import org.apache.archiva.configuration.RepositoryGroupConfiguration;
+import org.apache.archiva.indexer.merger.MergedRemoteIndexesScheduler;
+import org.apache.archiva.repository.EditableRepository;
+import org.apache.archiva.repository.EditableRepositoryGroup;
+import org.apache.archiva.repository.ManagedRepository;
+import org.apache.archiva.repository.RepositoryException;
+import org.apache.archiva.repository.RepositoryGroup;
+import org.apache.archiva.repository.RepositoryProvider;
+import org.apache.archiva.repository.RepositoryType;
+import org.apache.archiva.repository.event.RepositoryEvent;
+import org.apache.commons.lang3.StringUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Service;
+
+import javax.annotation.PostConstruct;
+import javax.annotation.PreDestroy;
+import javax.inject.Named;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import static org.apache.archiva.indexer.ArchivaIndexManager.DEFAULT_INDEX_PATH;
+
+/**
+ * This class manages repository groups for the RepositoryRegistry.
+ * It is tightly coupled with the {@link ArchivaRepositoryRegistry}.
+ *
+ * @author Martin Stockhammer <martin_s@apache.org>
+ */
+@Service("repositoryGroupHandler#default")
+public class RepositoryGroupHandler
+{
+    private static final Logger log = LoggerFactory.getLogger(RepositoryGroupHandler.class);
+
+    private final ArchivaRepositoryRegistry repositoryRegistry;
+    private final ConfigurationHandler configurationHandler;
+    private final MergedRemoteIndexesScheduler mergedRemoteIndexesScheduler;
+
+    private Map<String, RepositoryGroup> repositoryGroups = new HashMap<>();
+
+    /**
+     * Creates a new instance. All dependencies are injected on the constructor.
+     * @param repositoryRegistry the registry. To avoid circular dependencies via DI, this class registers itself on the registry.
+     * @param configurationHandler the configuration handler is used to retrieve and save configuration.
+     * @param mergedRemoteIndexesScheduler the index scheduler is used for merging the indexes from all group members
+     */
+    public RepositoryGroupHandler( ArchivaRepositoryRegistry repositoryRegistry,
+                                   ConfigurationHandler configurationHandler,
+                                   @Named("mergedRemoteIndexesScheduler#default") MergedRemoteIndexesScheduler mergedRemoteIndexesScheduler) {
+        this.configurationHandler = configurationHandler;
+        this.mergedRemoteIndexesScheduler = mergedRemoteIndexesScheduler;
+        this.repositoryRegistry = repositoryRegistry;
+    }
+
+    @PostConstruct
+    private void init() {
+        log.debug( "Initializing repository group handler " + repositoryRegistry.toString( ) );
+        // We are registering this class on the registry. This is necessary to avoid circular dependencies via injection.
+        this.repositoryRegistry.registerGroupHandler( this );
+    }
+
+    public void initializeFromConfig() {
+        this.repositoryGroups.clear();
+        this.repositoryGroups.putAll( getRepositorGroupsFromConfig( ) );
+    }
+
+    public Map<String, RepositoryGroup> getRepositorGroupsFromConfig() {
+        try {
+            List<RepositoryGroupConfiguration> repositoryGroupConfigurations =
+                this.configurationHandler.getBaseConfiguration().getRepositoryGroups();
+
+            if (repositoryGroupConfigurations == null) {
+                return Collections.emptyMap();
+            }
+
+            Map<String, RepositoryGroup> repositoryGroupMap = new LinkedHashMap<>(repositoryGroupConfigurations.size());
+
+            Map<RepositoryType, RepositoryProvider> providerMap = repositoryRegistry.getRepositoryProviderMap();
+            for (RepositoryGroupConfiguration repoConfig : repositoryGroupConfigurations) {
+                RepositoryType repositoryType = RepositoryType.valueOf(repoConfig.getType());
+                if (providerMap.containsKey(repositoryType)) {
+                    try {
+                        RepositoryGroup repo = createNewRepositoryGroup(providerMap.get(repositoryType), repoConfig);
+                        repositoryGroupMap.put(repo.getId(), repo);
+                    } catch (Exception e) {
+                        log.error("Could not create repository group {}: {}", repoConfig.getId(), e.getMessage(), e);
+                    }
+                }
+            }
+            return repositoryGroupMap;
+        } catch (Throwable e) {
+            log.error("Could not initialize repositories from config: {}", e.getMessage(), e);
+            return Collections.emptyMap();
+        }
+    }
+
+    public RepositoryGroup createNewRepositoryGroup(RepositoryProvider provider, RepositoryGroupConfiguration config) throws RepositoryException
+    {
+        RepositoryGroup repositoryGroup = provider.createRepositoryGroup(config);
+        repositoryGroup.registerEventHandler( RepositoryEvent.ANY, repositoryRegistry);
+        updateRepositoryReferences(provider, repositoryGroup, config);
+        return repositoryGroup;
+    }
+
+    public void updateRepositoryReferences( RepositoryProvider provider, RepositoryGroup group, RepositoryGroupConfiguration configuration) {
+        if (group instanceof EditableRepositoryGroup ) {
+            EditableRepositoryGroup eGroup = (EditableRepositoryGroup) group;
+            eGroup.setRepositories(configuration.getRepositories().stream()
+                .map(r -> repositoryRegistry.getManagedRepository(r)).collect( Collectors.toList()));
+        }
+    }
+
+    /**
+     * Adds a new repository group to the current list, or replaces the repository group definition with
+     * the same id, if it exists already.
+     * The change is saved to the configuration immediately.
+     *
+     * @param repositoryGroup the new repository group.
+     * @throws RepositoryException if the new repository group could not be saved to the configuration.
+     */
+    public RepositoryGroup putRepositoryGroup( RepositoryGroup repositoryGroup ) throws RepositoryException {
+            final String id = repositoryGroup.getId();
+            RepositoryGroup originRepoGroup = repositoryGroups.put(id, repositoryGroup);
+            try {
+                if (originRepoGroup != null && originRepoGroup != repositoryGroup) {
+                    originRepoGroup.close();
+                }
+                RepositoryProvider provider = repositoryRegistry.getProvider( repositoryGroup.getType());
+                RepositoryGroupConfiguration newCfg = provider.getRepositoryGroupConfiguration(repositoryGroup);
+                Configuration configuration = this.configurationHandler.getBaseConfiguration();
+                updateRepositoryReferences(provider, repositoryGroup, newCfg);
+                RepositoryGroupConfiguration oldCfg = configuration.findRepositoryGroupById(id);
+                if (oldCfg != null) {
+                    configuration.removeRepositoryGroup(oldCfg);
+                }
+                configuration.addRepositoryGroup(newCfg);
+                repositoryRegistry.saveConfiguration(configuration);
+                return repositoryGroup;
+            } catch (Exception e) {
+                // Rollback
+                if (originRepoGroup != null) {
+                    repositoryGroups.put(id, originRepoGroup);
+                } else {
+                    repositoryGroups.remove(id);
+                }
+                log.error("Exception during configuration update {}", e.getMessage(), e);
+                throw new RepositoryException("Could not save the configuration" + (e.getMessage() == null ? "" : ": " + e.getMessage()));
+            }
+    }
+
+    /**
+     * Adds a new repository group or updates the repository with the same id, if it exists already.
+     * The configuration is saved immediately.
+     *
+     * @param repositoryGroupConfiguration the repository configuration
+     * @return the updated or created repository
+     * @throws RepositoryException if an error occurs, or the configuration is not valid.
+     */
+    public RepositoryGroup putRepositoryGroup( RepositoryGroupConfiguration repositoryGroupConfiguration ) throws RepositoryException {
+            final String id = repositoryGroupConfiguration.getId();
+            final RepositoryType repositoryType = RepositoryType.valueOf(repositoryGroupConfiguration.getType());
+            Configuration configuration = this.configurationHandler.getBaseConfiguration();
+            RepositoryGroup repo = repositoryGroups.get(id);
+            RepositoryGroupConfiguration oldCfg = repo != null ? repositoryRegistry.getProvider(repositoryType).getRepositoryGroupConfiguration(repo) : null;
+            repo = putRepositoryGroup(repositoryGroupConfiguration, configuration);
+            try {
+                repositoryRegistry.saveConfiguration(configuration);
+            } catch ( IndeterminateConfigurationException | RegistryException e) {
+                if (oldCfg != null) {
+                    repositoryRegistry.getProvider(repositoryType).updateRepositoryGroupInstance((EditableRepositoryGroup) repo, oldCfg);
+                }
+                log.error("Could not save the configuration for repository group {}: {}", id, e.getMessage(), e);
+                throw new RepositoryException("Could not save the configuration for repository group " + id + ": " + e.getMessage());
+            }
+            return repo;
+    }
+
+    public RepositoryGroup putRepositoryGroup( RepositoryGroupConfiguration repositoryGroupConfiguration, Configuration configuration ) throws RepositoryException {
+            final String id = repositoryGroupConfiguration.getId();
+            final RepositoryType repoType = RepositoryType.valueOf(repositoryGroupConfiguration.getType());
+            RepositoryGroup repo;
+            setRepositoryGroupDefaults(repositoryGroupConfiguration);
+            if (repositoryGroups.containsKey(id)) {
+                repo = repositoryGroups.get(id);
+                if (repo instanceof EditableRepositoryGroup) {
+                    repositoryRegistry.getProvider(repoType).updateRepositoryGroupInstance((EditableRepositoryGroup) repo, repositoryGroupConfiguration);
+                } else {
+                    throw new RepositoryException("The repository is not editable " + id);
+                }
+            } else {
+                repo = repositoryRegistry.getProvider(repoType).createRepositoryGroup(repositoryGroupConfiguration);
+                repositoryGroups.put(id, repo);
+            }
+            updateRepositoryReferences(repositoryRegistry.getProvider(repoType), repo, repositoryGroupConfiguration);
+            replaceOrAddRepositoryConfig(repositoryGroupConfiguration, configuration);
+            return repo;
+    }
+
+    private void setRepositoryGroupDefaults(RepositoryGroupConfiguration repositoryGroupConfiguration) {
+        if ( StringUtils.isEmpty(repositoryGroupConfiguration.getMergedIndexPath())) {
+            repositoryGroupConfiguration.setMergedIndexPath(DEFAULT_INDEX_PATH);
+        }
+        if (repositoryGroupConfiguration.getMergedIndexTtl() <= 0) {
+            repositoryGroupConfiguration.setMergedIndexTtl(300);
+        }
+        if (StringUtils.isEmpty(repositoryGroupConfiguration.getCronExpression())) {
+            repositoryGroupConfiguration.setCronExpression("0 0 03 ? * MON");
+        }
+    }
+
+    private void replaceOrAddRepositoryConfig(RepositoryGroupConfiguration repositoryGroupConfiguration, Configuration configuration) {
+        RepositoryGroupConfiguration oldCfg = configuration.findRepositoryGroupById(repositoryGroupConfiguration.getId());
+        if (oldCfg != null) {
+            configuration.removeRepositoryGroup(oldCfg);
+        }
+        configuration.addRepositoryGroup(repositoryGroupConfiguration);
+    }
+
+    public void removeRepositoryFromGroups( ManagedRepository repo) {
+        if (repo != null) {
+            repositoryGroups.values().stream().filter(repoGroup -> repoGroup instanceof EditableRepository ).
+                map(repoGroup -> (EditableRepositoryGroup) repoGroup).forEach(repoGroup -> repoGroup.removeRepository(repo));
+        }
+    }
+
+    /**
+     * Removes a repository group from the registry and configuration, if it exists.
+     * The change is saved to the configuration immediately.
+     *
+     * @param id the id of the repository group to remove
+     * @throws RepositoryException if a error occurs during configuration save
+     */
+    public void removeRepositoryGroup( final String id ) throws RepositoryException {
+        RepositoryGroup repo = getRepositoryGroup(id);
+        if (repo != null) {
+            try {
+                repo = repositoryGroups.remove(id);
+                if (repo != null) {
+                    repo.close();
+                    Configuration configuration = this.configurationHandler.getBaseConfiguration();
+                    RepositoryGroupConfiguration cfg = configuration.findRepositoryGroupById(id);
+                    if (cfg != null) {
+                        configuration.removeRepositoryGroup(cfg);
+                    }
+                    this.configurationHandler.save(configuration, ConfigurationHandler.REGISTRY_EVENT_TAG );
+                }
+
+            } catch (RegistryException | IndeterminateConfigurationException e) {
+                // Rollback
+                log.error("Could not save config after repository removal: {}", e.getMessage(), e);
+                repositoryGroups.put(repo.getId(), repo);
+                throw new RepositoryException("Could not save configuration after repository removal: " + e.getMessage());
+            }
+        }
+    }
+
+    public void removeRepositoryGroup( String id, Configuration configuration ) throws RepositoryException {
+        RepositoryGroup repo = repositoryGroups.get(id);
+        if (repo != null) {
+                repo = repositoryGroups.remove(id);
+                if (repo != null) {
+                    repo.close();
+                    RepositoryGroupConfiguration cfg = configuration.findRepositoryGroupById(id);
+                    if (cfg != null) {
+                        configuration.removeRepositoryGroup(cfg);
+                    }
+                }
+        }
+
+    }
+
+    public RepositoryGroup getRepositoryGroup( String groupId ) {
+        return repositoryGroups.get(groupId);
+    }
+
+    public Collection<RepositoryGroup> getRepositoryGroups() {
+        return repositoryGroups.values( );
+    }
+
+    public boolean hasRepositoryGroup(String id) {
+        return repositoryGroups.containsKey( id );
+    }
+
+    @PreDestroy
+    private void destroy() {
+        this.close( );
+    }
+
+    public void close() {
+        for (RepositoryGroup group : repositoryGroups.values()) {
+            try
+            {
+                group.close( );
+            } catch (Throwable e) {
+                log.error( "Could not close repository group {}: {}", group.getId( ), e.getMessage( ) );
+            }
+        }
+        this.repositoryGroups.clear();
+    }
+
+}
diff --git a/archiva-modules/archiva-base/archiva-repository-layer/src/test/java/org/apache/archiva/repository/base/ArchivaRepositoryRegistryTest.java b/archiva-modules/archiva-base/archiva-repository-layer/src/test/java/org/apache/archiva/repository/base/ArchivaRepositoryRegistryTest.java
index 58965ed18..b7cbf1fb5 100644
--- a/archiva-modules/archiva-base/archiva-repository-layer/src/test/java/org/apache/archiva/repository/base/ArchivaRepositoryRegistryTest.java
+++ b/archiva-modules/archiva-base/archiva-repository-layer/src/test/java/org/apache/archiva/repository/base/ArchivaRepositoryRegistryTest.java
@@ -66,6 +66,10 @@ public class ArchivaRepositoryRegistryTest
     @Inject
     ArchivaConfiguration archivaConfiguration;
 
+    @SuppressWarnings( "unused" )
+    @Inject
+    RepositoryGroupHandler repositoryGroupHandler;
+
     private static final Path userCfg = Paths.get(System.getProperty( "user.home" ), ".m2/archiva.xml");
 
     private static Path cfgCopy;