DatabaseService that uses Copycat Raft to provide a strongly consistent and durable database.
diff --git a/core/store/dist/src/main/java/org/onlab/onos/store/service/WriteResult.java b/core/store/dist/src/main/java/org/onlab/onos/store/service/WriteResult.java
new file mode 100644
index 0000000..64e9b74
--- /dev/null
+++ b/core/store/dist/src/main/java/org/onlab/onos/store/service/WriteResult.java
@@ -0,0 +1,31 @@
+package org.onlab.onos.store.service;
+
+import org.onlab.onos.store.service.impl.VersionedValue;
+
+/**
+ * Database write result.
+ */
+public class WriteResult {
+
+    private final String tableName;
+    private final String key;
+    private final VersionedValue previousValue;
+
+    public WriteResult(String tableName, String key, VersionedValue previousValue) {
+        this.tableName = tableName;
+        this.key = key;
+        this.previousValue = previousValue;
+    }
+
+    public String tableName() {
+        return tableName;
+    }
+
+    public String key() {
+        return key;
+    }
+
+    public VersionedValue previousValue() {
+        return previousValue;
+    }
+}