diff --git a/src/main/java/org/gcube/documentstore/persistence/FallbackPersistenceBackend.java b/src/main/java/org/gcube/documentstore/persistence/FallbackPersistenceBackend.java
index 954f3ed..d0ddaee 100644
--- a/src/main/java/org/gcube/documentstore/persistence/FallbackPersistenceBackend.java
+++ b/src/main/java/org/gcube/documentstore/persistence/FallbackPersistenceBackend.java
@@ -43,7 +43,16 @@ public class FallbackPersistenceBackend extends PersistenceBackend {
 		// Nothing TO DO
 	}
 	
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	public void close() throws Exception {
+		// Nothing TO DO
+	}
+
 	
+
 	/**
 	 * {@inheritDoc}
 	 * This method is synchronized on {@link File} used, so any actions which 
@@ -69,20 +78,7 @@ public class FallbackPersistenceBackend extends PersistenceBackend {
 		}
 	}
 	
-	/**
-	 * {@inheritDoc}
-	 */
-	@Override
-	public void close() throws Exception {
-		// Nothing TO DO
-	}
-
-	@Override
-	protected void disconnect() throws Exception {
-		// TODO Auto-generated method stub
-		
-	}
-
+	
 	
 	
 }
diff --git a/src/main/java/org/gcube/documentstore/persistence/PersistenceBackend.java b/src/main/java/org/gcube/documentstore/persistence/PersistenceBackend.java
index b71bb41..b69bcd7 100644
--- a/src/main/java/org/gcube/documentstore/persistence/PersistenceBackend.java
+++ b/src/main/java/org/gcube/documentstore/persistence/PersistenceBackend.java
@@ -82,7 +82,7 @@ public abstract class PersistenceBackend {
 
 	/**
 	 * Prepare the connection to persistence.
-	 * This method must be used by implementation class to open 
+	 * This method must be used by implementation class to prepare  
 	 * the connection with the persistence storage, DB, file etc.
 	 * @param configuration The configuration to create the connection
 	 * @throws Exception if fails
@@ -90,22 +90,25 @@ public abstract class PersistenceBackend {
 	protected abstract void prepareConnection(PersistenceBackendConfiguration configuration) throws Exception;
 
 	/**
-	 * This method is for open db connection 
+	 * This method is used to open db connection 
 	 * @throws Exception
 	 */
 	protected abstract  void openConnection() throws Exception ;
 	
 	/**
-	 * This method is for close db connection 
+	 * This method is used to close db connection 
 	 * @throws Exception
 	 */
 	protected abstract void close() throws Exception;
 	
 	/**
-	 * This method is for close db and disconnect from cluster 
+	 * This method is used to close db and clean the configuration.
+	 * It is used when there are too much TimeoutException trying to persist
+	 * records.
 	 * @throws Exception
 	 */
-	protected abstract void disconnect() throws Exception ;
+	protected void closeAndClean() throws Exception {}
+	;
 	
 	/**
 	 * This method contains the code to save the {@link Record}
@@ -158,7 +161,7 @@ public abstract class PersistenceBackend {
 						//PersistenceBackendFactory.renew(this);
 						countFallback=0;
 						//disconnect 	
-						this.disconnect();
+						this.closeAndClean();
 					}
 				}
 				else{