Deprecate ClusterMessageHandler

Change-Id: I569fd1da7ba3c671a488ad747144bfd7b3161a4e
diff --git a/core/api/src/main/java/org/onosproject/store/cluster/messaging/ClusterMessageHandler.java b/core/api/src/main/java/org/onosproject/store/cluster/messaging/ClusterMessageHandler.java
index 6252ec0..dc78d43 100644
--- a/core/api/src/main/java/org/onosproject/store/cluster/messaging/ClusterMessageHandler.java
+++ b/core/api/src/main/java/org/onosproject/store/cluster/messaging/ClusterMessageHandler.java
@@ -17,7 +17,10 @@
 
 /**
  * Interface for handling cluster messages.
+ *
+ * @deprecated since 1.12
  */
+@Deprecated
 public interface ClusterMessageHandler {
 
     /**