titan transactions in type system persistence

repository/src/main/java/org/apache/hadoop/metadata/repository/graph/TitanGraphProvider.java

@@ -25,6 +25,8 @@ import org.apache.commons.configuration.ConfigurationException;
 import org.apache.commons.configuration.PropertiesConfiguration;
 import org.apache.hadoop.metadata.MetadataException;
 import org.apache.hadoop.metadata.PropertiesUtil;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import javax.inject.Singleton;
 import java.util.Iterator;
@@ -34,6 +36,8 @@ import java.util.Iterator;
  */
 public class TitanGraphProvider implements GraphProvider<TitanGraph> {
 
+    private static final Logger LOG = LoggerFactory.getLogger(TitanGraphProvider.class);
+
     /**
      * Constant for the configuration property that indicates the prefix.
      */
@@ -51,6 +55,7 @@ public class TitanGraphProvider implements GraphProvider<TitanGraph> {
                 String value = (String) configProperties.getProperty(key);
                 key = key.substring(METADATA_PREFIX.length());
                 graphConfig.setProperty(key, value);
+                LOG.info("Using graph property {}={}", key, value);
             }
         }
 

repository/src/main/java/org/apache/hadoop/metadata/repository/typestore/GraphBackedTypeStore.java

@@ -207,8 +207,11 @@ public class GraphBackedTypeStore implements ITypeStore {
 
     @Override
     public TypesDef restore() throws MetadataException {
+        try {
+            titanGraph.rollback();  //Cleanup previous state
             //Get all vertices for type system
-        Iterator vertices = titanGraph.query().has(Constants.VERTEX_TYPE_PROPERTY_KEY, VERTEX_TYPE).vertices().iterator();
+            Iterator vertices =
+                    titanGraph.query().has(Constants.VERTEX_TYPE_PROPERTY_KEY, VERTEX_TYPE).vertices().iterator();
 
             ImmutableList.Builder<EnumTypeDefinition> enums = ImmutableList.builder();
             ImmutableList.Builder<StructTypeDefinition> structs = ImmutableList.builder();
@@ -220,7 +223,7 @@ public class GraphBackedTypeStore implements ITypeStore {
                 DataTypes.TypeCategory typeCategory = vertex.getProperty(Constants.TYPE_CATEGORY_PROPERTY_KEY);
                 String typeName = vertex.getProperty(Constants.TYPENAME_PROPERTY_KEY);
                 LOG.info("Restoring type {}.{}", typeCategory, typeName);
-            switch(typeCategory) {
+                switch (typeCategory) {
                 case ENUM:
                     enums.add(getEnumType(vertex));
                     break;
@@ -246,7 +249,11 @@ public class GraphBackedTypeStore implements ITypeStore {
                     throw new IllegalArgumentException("Unhandled type category " + typeCategory);
                 }
             }
+            titanGraph.commit();
             return TypeUtils.getTypesDef(enums.build(), structs.build(), traits.build(), classTypes.build());
+        } finally {
+            titanGraph.rollback();
+        }
     }
 
     private EnumTypeDefinition getEnumType(Vertex vertex) {

repository/src/main/java/org/apache/hadoop/metadata/services/DefaultMetadataService.java

@@ -20,6 +20,7 @@ package org.apache.hadoop.metadata.services;
 
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
+import com.google.inject.Injector;
 import org.apache.hadoop.metadata.MetadataException;
 import org.apache.hadoop.metadata.discovery.SearchIndexer;
 import org.apache.hadoop.metadata.listener.EntityChangeListener;
@@ -73,9 +74,22 @@ public class DefaultMetadataService implements MetadataService {
         this.typeSystem = TypeSystem.getInstance();
         this.repository = repository;
 
+        restoreTypeSystem();
         registerListener(searchIndexer);
     }
 
+    private void restoreTypeSystem() {
+        LOG.info("Restoring type system from the store");
+        try {
+            TypesDef typesDef = typeStore.restore();
+            typeSystem.defineTypes(typesDef);
+        } catch (MetadataException e) {
+            throw new RuntimeException(e);
+        }
+        LOG.info("Restored type system from the store");
+    }
+
+
     /**
      * Creates a new type based on the type system to enable adding
      * entities (instances for types).

webapp/src/main/java/org/apache/hadoop/metadata/web/listeners/GuiceServletConfig.java

@@ -20,7 +20,11 @@ package org.apache.hadoop.metadata.web.listeners;
 
 import com.google.inject.Guice;
 import com.google.inject.Injector;
+import com.google.inject.TypeLiteral;
+import com.google.inject.matcher.Matchers;
 import com.google.inject.servlet.GuiceServletContextListener;
+import com.google.inject.spi.TypeEncounter;
+import com.google.inject.spi.TypeListener;
 import com.sun.jersey.api.core.PackagesResourceConfig;
 import com.sun.jersey.guice.JerseyServletModule;
 import com.sun.jersey.guice.spi.container.servlet.GuiceContainer;
@@ -41,6 +45,8 @@ import javax.servlet.ServletContextEvent;
 import java.util.HashMap;
 import java.util.Map;
 
+import static com.google.inject.matcher.Matchers.*;
+
 public class GuiceServletConfig extends GuiceServletContextListener {
 
     private static final Logger LOG = LoggerFactory.getLogger(GuiceServletConfig.class);
@@ -105,22 +111,6 @@ public class GuiceServletConfig extends GuiceServletContextListener {
         // perform login operations
         LoginProcessor loginProcessor = new LoginProcessor();
         loginProcessor.login();
-
-        restoreTypeSystem();
-    }
-
-    private void restoreTypeSystem() {
-        LOG.info("Restoring type system from the store");
-        Injector injector = getInjector();
-        ITypeStore typeStore = injector.getInstance(ITypeStore.class);
-        try {
-            TypesDef typesDef = typeStore.restore();
-            TypeSystem typeSystem = injector.getInstance(TypeSystem.class);
-            typeSystem.defineTypes(typesDef);
-        } catch (MetadataException e) {
-            throw new RuntimeException(e);
-        }
-        LOG.info("Restored type system from the store");
     }
 
     @Override