diff --git a/README.md b/README.md
index 702046342a3b..49fa9bb0a501 100644
--- a/README.md
+++ b/README.md
@@ -152,9 +152,13 @@ The main contents of that module are the EPGM data model and a corresponding POJ
 implementation which is used in Flink™. The persistent representation of the EPGM
 is also contained in gradoop-common and together with its mapping to HBase™.
 
+### gradoop-accumulo
+
+Input and output formats for reading and writing graph collections from [Apache Accumulo](https://accumulo.apache.org/).
+
 ### gradoop-hbase
 
-Input and output formats for reading and writing graph collections from Apache HBase.
+Input and output formats for reading and writing graph collections from [Apache HBase](https://hbase.apache.org/).
 
 ### gradoop-flink
 
diff --git a/gradoop-accumulo/src/main/java/org/gradoop/common/storage/impl/accumulo/AccumuloEPGMStore.java b/gradoop-accumulo/src/main/java/org/gradoop/common/storage/impl/accumulo/AccumuloEPGMStore.java
index 58b5a9f4ed82..0ea881989364 100644
--- a/gradoop-accumulo/src/main/java/org/gradoop/common/storage/impl/accumulo/AccumuloEPGMStore.java
+++ b/gradoop-accumulo/src/main/java/org/gradoop/common/storage/impl/accumulo/AccumuloEPGMStore.java
@@ -46,7 +46,7 @@
 import org.gradoop.common.storage.api.EPGMStore;
 import org.gradoop.common.storage.impl.accumulo.constants.AccumuloDefault;
 import org.gradoop.common.storage.impl.accumulo.handler.AccumuloRowHandler;
-import org.gradoop.common.storage.impl.accumulo.iterator.client.CacheClosableIteratorIterator;
+import org.gradoop.common.storage.impl.accumulo.iterator.client.CacheClosableIterator;
 import org.gradoop.common.storage.impl.accumulo.iterator.client.CloseableIterator;
 import org.gradoop.common.storage.impl.accumulo.iterator.tserver.GradoopEdgeIterator;
 import org.gradoop.common.storage.impl.accumulo.iterator.tserver.GradoopGraphHeadIterator;
@@ -211,7 +211,7 @@ public CloseableIterator<V> getVertexSpace() throws IOException {
   public CloseableIterator<V> getVertexSpace(int cacheSize) throws IOException {
     BatchScanner scanner = createBatchScanner(getVertexTableName(), GradoopVertexIterator.class);
     scanner.setRanges(Lists.newArrayList(new Range((Text) null, null)));
-    return new CacheClosableIteratorIterator<>(scanner, new GradoopVertexIterator(), config
+    return new CacheClosableIterator<>(scanner, new GradoopVertexIterator(), config
       .getVertexHandler(), cacheSize);
   }
 
@@ -224,7 +224,7 @@ public CloseableIterator<E> getEdgeSpace() throws IOException {
   public CloseableIterator<E> getEdgeSpace(int cacheSize) throws IOException {
     BatchScanner scanner = createBatchScanner(getEdgeTableName(), GradoopEdgeIterator.class);
     scanner.setRanges(Lists.newArrayList(new Range((Text) null, null)));
-    return new CacheClosableIteratorIterator<>(scanner, new GradoopEdgeIterator(), config
+    return new CacheClosableIterator<>(scanner, new GradoopEdgeIterator(), config
       .getEdgeHandler(), cacheSize);
   }
 
@@ -237,7 +237,7 @@ public CloseableIterator<G> getGraphSpace() throws IOException {
   public CloseableIterator<G> getGraphSpace(int cacheSize) throws IOException {
     BatchScanner scanner = createBatchScanner(getGraphHeadName(), GradoopGraphHeadIterator.class);
     scanner.setRanges(Lists.newArrayList(new Range((Text) null, null)));
-    return new CacheClosableIteratorIterator<>(scanner, new GradoopGraphHeadIterator(), config
+    return new CacheClosableIterator<>(scanner, new GradoopGraphHeadIterator(), config
       .getGraphHandler(), cacheSize);
   }
 
diff --git a/gradoop-accumulo/src/main/java/org/gradoop/common/storage/impl/accumulo/iterator/client/CacheClosableIteratorIterator.java b/gradoop-accumulo/src/main/java/org/gradoop/common/storage/impl/accumulo/iterator/client/CacheClosableIterator.java
similarity index 94%
rename from gradoop-accumulo/src/main/java/org/gradoop/common/storage/impl/accumulo/iterator/client/CacheClosableIteratorIterator.java
rename to gradoop-accumulo/src/main/java/org/gradoop/common/storage/impl/accumulo/iterator/client/CacheClosableIterator.java
index dfcb37e8a940..903d4adf777d 100644
--- a/gradoop-accumulo/src/main/java/org/gradoop/common/storage/impl/accumulo/iterator/client/CacheClosableIteratorIterator.java
+++ b/gradoop-accumulo/src/main/java/org/gradoop/common/storage/impl/accumulo/iterator/client/CacheClosableIterator.java
@@ -31,12 +31,12 @@
 import java.util.Map;
 
 /**
- * cache iterator for scanner result
+ * cache iterator for accumulo scanner's result
  *
  * @param <E> EPGM Element as reading result
  * @param <R> ElementRow from iterator rpc result
  */
-public class CacheClosableIteratorIterator<E extends EPGMElement, R extends ElementRow> implements
+public class CacheClosableIterator<E extends EPGMElement, R extends ElementRow> implements
   CloseableIterator<E> {
 
   /**
@@ -76,7 +76,7 @@ public class CacheClosableIteratorIterator<E extends EPGMElement, R extends Elem
    * @param handler result element row handler
    * @param cacheSize result cache size
    */
-  public CacheClosableIteratorIterator(
+  public CacheClosableIterator(
     BatchScanner scanner,
     BaseElementIterator<R> codec,
     AccumuloRowHandler<E, ?, R> handler,
diff --git a/gradoop-accumulo/src/main/java/org/gradoop/common/storage/impl/accumulo/iterator/tserver/GradoopEdgeIterator.java b/gradoop-accumulo/src/main/java/org/gradoop/common/storage/impl/accumulo/iterator/tserver/GradoopEdgeIterator.java
index 204e1e089649..b142a84e0e5f 100644
--- a/gradoop-accumulo/src/main/java/org/gradoop/common/storage/impl/accumulo/iterator/tserver/GradoopEdgeIterator.java
+++ b/gradoop-accumulo/src/main/java/org/gradoop/common/storage/impl/accumulo/iterator/tserver/GradoopEdgeIterator.java
@@ -23,7 +23,7 @@
 import org.apache.accumulo.core.iterators.SortedKeyValueIterator;
 import org.gradoop.common.storage.impl.accumulo.constants.AccumuloTables;
 import org.gradoop.common.storage.impl.accumulo.row.EdgeRow;
-import org.gradoop.common.utils.Json;
+import org.gradoop.common.utils.JsonUtils;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
@@ -42,7 +42,7 @@ public class GradoopEdgeIterator extends BaseElementIterator<EdgeRow> {
   public EdgeRow fromRow(@Nonnull Map.Entry<Key, Value> pair) {
     //TODO: use kryo instead of json for better performance
     //map from serialize content
-    EdgeRow content = Json.loads(pair.getValue().get(), EdgeRow.class);
+    EdgeRow content = JsonUtils.loads(pair.getValue().get(), EdgeRow.class);
     content.setId(pair.getKey().getRow().toString());
     //read from content
     return content;
@@ -52,7 +52,7 @@ public EdgeRow fromRow(@Nonnull Map.Entry<Key, Value> pair) {
   @Override
   public Pair<Key, Value> toRow(@Nonnull EdgeRow record) {
     //write to content
-    return new Pair<>(new Key(record.getId()), new Value(Json.dumps(record)));
+    return new Pair<>(new Key(record.getId()), new Value(JsonUtils.dumps(record)));
   }
 
   @Nonnull
@@ -125,7 +125,7 @@ private EdgeRow readLine(SortedKeyValueIterator<Key, Value> source) throws IOExc
       source.next();
     }
 
-    LOG.info(String.format("[edge]readLine=>%s", Json.dumps(row)));
+    LOG.info(String.format("[edge]readLine=>%s", JsonUtils.dumps(row)));
     return row;
   }
 }
diff --git a/gradoop-accumulo/src/main/java/org/gradoop/common/storage/impl/accumulo/iterator/tserver/GradoopGraphHeadIterator.java b/gradoop-accumulo/src/main/java/org/gradoop/common/storage/impl/accumulo/iterator/tserver/GradoopGraphHeadIterator.java
index efc157f21953..118538afa80d 100644
--- a/gradoop-accumulo/src/main/java/org/gradoop/common/storage/impl/accumulo/iterator/tserver/GradoopGraphHeadIterator.java
+++ b/gradoop-accumulo/src/main/java/org/gradoop/common/storage/impl/accumulo/iterator/tserver/GradoopGraphHeadIterator.java
@@ -23,7 +23,7 @@
 import org.apache.accumulo.core.iterators.SortedKeyValueIterator;
 import org.gradoop.common.storage.impl.accumulo.constants.AccumuloTables;
 import org.gradoop.common.storage.impl.accumulo.row.GraphHeadRow;
-import org.gradoop.common.utils.Json;
+import org.gradoop.common.utils.JsonUtils;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
@@ -42,7 +42,7 @@ public class GradoopGraphHeadIterator extends BaseElementIterator<GraphHeadRow>
   public GraphHeadRow fromRow(@Nonnull Map.Entry<Key, Value> pair) {
     //TODO: use kryo instead of json for better performance
     //map from serialize content
-    GraphHeadRow content = Json.loads(pair.getValue().get(), GraphHeadRow.class);
+    GraphHeadRow content = JsonUtils.loads(pair.getValue().get(), GraphHeadRow.class);
     content.setId(pair.getKey().getRow().toString());
     //read from content
     return content;
@@ -52,7 +52,7 @@ public GraphHeadRow fromRow(@Nonnull Map.Entry<Key, Value> pair) {
   @Override
   public Pair<Key, Value> toRow(@Nonnull GraphHeadRow record) {
     //write to content
-    return new Pair<>(new Key(record.getId()), new Value(Json.dumps(record)));
+    return new Pair<>(new Key(record.getId()), new Value(JsonUtils.dumps(record)));
   }
 
   @Nonnull
@@ -116,7 +116,7 @@ private GraphHeadRow readLine(SortedKeyValueIterator<Key, Value> source) throws
       source.next();
     }
 
-    LOG.info(String.format("[graph]readLine=>%s", Json.dumps(row)));
+    LOG.info(String.format("[graph]readLine=>%s", JsonUtils.dumps(row)));
     return row;
   }
 }
diff --git a/gradoop-accumulo/src/main/java/org/gradoop/common/storage/impl/accumulo/iterator/tserver/GradoopVertexIterator.java b/gradoop-accumulo/src/main/java/org/gradoop/common/storage/impl/accumulo/iterator/tserver/GradoopVertexIterator.java
index 76e65633127b..085abc6b231d 100644
--- a/gradoop-accumulo/src/main/java/org/gradoop/common/storage/impl/accumulo/iterator/tserver/GradoopVertexIterator.java
+++ b/gradoop-accumulo/src/main/java/org/gradoop/common/storage/impl/accumulo/iterator/tserver/GradoopVertexIterator.java
@@ -23,7 +23,7 @@
 import org.apache.accumulo.core.iterators.SortedKeyValueIterator;
 import org.gradoop.common.storage.impl.accumulo.constants.AccumuloTables;
 import org.gradoop.common.storage.impl.accumulo.row.VertexRow;
-import org.gradoop.common.utils.Json;
+import org.gradoop.common.utils.JsonUtils;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
@@ -42,7 +42,7 @@ public class GradoopVertexIterator extends BaseElementIterator<VertexRow> {
   public VertexRow fromRow(@Nonnull Map.Entry<Key, Value> pair) {
     //TODO: use kryo instead of json for better performance
     //map from serialize content
-    VertexRow content = Json.loads(pair.getValue().get(), VertexRow.class);
+    VertexRow content = JsonUtils.loads(pair.getValue().get(), VertexRow.class);
     content.setId(pair.getKey().getRow().toString());
     //read from content
     return content;
@@ -52,7 +52,7 @@ public VertexRow fromRow(@Nonnull Map.Entry<Key, Value> pair) {
   @Override
   public Pair<Key, Value> toRow(@Nonnull VertexRow record) {
     //write to content
-    return new Pair<>(new Key(record.getId()), new Value(Json.dumps(record)));
+    return new Pair<>(new Key(record.getId()), new Value(JsonUtils.dumps(record)));
   }
 
   @Nonnull
@@ -119,7 +119,7 @@ private VertexRow readLine(SortedKeyValueIterator<Key, Value> source) throws IOE
       source.next();
     }
 
-    LOG.info(String.format("[vertex]readLine=>%s", Json.dumps(row)));
+    LOG.info(String.format("[vertex]readLine=>%s", JsonUtils.dumps(row)));
     return row;
   }
 
diff --git a/gradoop-accumulo/src/main/java/org/gradoop/common/utils/Json.java b/gradoop-accumulo/src/main/java/org/gradoop/common/utils/JsonUtils.java
similarity index 98%
rename from gradoop-accumulo/src/main/java/org/gradoop/common/utils/Json.java
rename to gradoop-accumulo/src/main/java/org/gradoop/common/utils/JsonUtils.java
index 0c27b60060e3..93d89e0a11ef 100644
--- a/gradoop-accumulo/src/main/java/org/gradoop/common/utils/Json.java
+++ b/gradoop-accumulo/src/main/java/org/gradoop/common/utils/JsonUtils.java
@@ -25,7 +25,7 @@
 /**
  * json serialize utils
  */
-public final class Json {
+public final class JsonUtils {
 
   /**
    * normal mapper
diff --git a/pom.xml b/pom.xml
index a51c1f7a8463..3eb89e0c698d 100644
--- a/pom.xml
+++ b/pom.xml
@@ -109,7 +109,7 @@
         <license.licenseName>apache_v2</license.licenseName>
 
         <!-- alpha order require -->
-        <dep.accumulo.version>1.8.1</dep.accumulo.version>
+        <dep.accumulo.version>1.9.0</dep.accumulo.version>
         <dep.bson.version>3.6.3</dep.bson.version>
         <dep.flink.version>1.3.1</dep.flink.version>
         <dep.gdl.version>0.3</dep.gdl.version>