[ONOS-6487] Catch and log exceptions that occur during replication in ECM

Change-Id: I27135677af1331f1782739adc7eeb517a623e119
diff --git a/core/store/primitives/src/main/java/org/onosproject/store/primitives/impl/EventuallyConsistentMapImpl.java b/core/store/primitives/src/main/java/org/onosproject/store/primitives/impl/EventuallyConsistentMapImpl.java
index 41b6afd..97efec4 100644
--- a/core/store/primitives/src/main/java/org/onosproject/store/primitives/impl/EventuallyConsistentMapImpl.java
+++ b/core/store/primitives/src/main/java/org/onosproject/store/primitives/impl/EventuallyConsistentMapImpl.java
@@ -922,15 +922,19 @@
             items.forEach(item -> map.compute(item.key(), (key, existing) ->
                     item.isNewerThan(existing) ? item : existing));
             communicationExecutor.execute(() -> {
-                clusterCommunicator.unicast(ImmutableList.copyOf(map.values()),
-                                            updateMessageSubject,
-                                            serializer::encode,
-                                            peer)
-                                   .whenComplete((result, error) -> {
-                                       if (error != null) {
-                                           log.debug("Failed to send to {}", peer, error);
-                                       }
-                                   });
+                try {
+                    clusterCommunicator.unicast(ImmutableList.copyOf(map.values()),
+                            updateMessageSubject,
+                            serializer::encode,
+                            peer)
+                            .whenComplete((result, error) -> {
+                                if (error != null) {
+                                    log.debug("Failed to send to {}", peer, error);
+                                }
+                            });
+                } catch (Exception e) {
+                    log.warn("Failed to send to {}", peer, e);
+                }
             });
         }
     }