Added feature to count exceptions ocurred when operating distributed primitives

Change-Id: I24017e61cd2aefd1cf78aa5b241a3219e3e89b32

@@ -51,34 +51,34 @@ public class DefaultAsyncAtomicCounter implements AsyncAtomicCounter {
     public CompletableFuture<Long> incrementAndGet() {
     public CompletableFuture<Long> incrementAndGet() {
         final MeteringAgent.Context timer = monitor.startTimer(INCREMENT_AND_GET);
         final MeteringAgent.Context timer = monitor.startTimer(INCREMENT_AND_GET);
         return addAndGet(1L)
         return addAndGet(1L)
-                .whenComplete((r, e) -> timer.stop());
+                .whenComplete((r, e) -> timer.stop(e));
     }
     }
 
 
     @Override
     @Override
     public CompletableFuture<Long> get() {
     public CompletableFuture<Long> get() {
         final MeteringAgent.Context timer = monitor.startTimer(GET);
         final MeteringAgent.Context timer = monitor.startTimer(GET);
         return database.counterGet(name)
         return database.counterGet(name)
-                .whenComplete((r, e) -> timer.stop());
+                .whenComplete((r, e) -> timer.stop(e));
     }
     }
 
 
     @Override
     @Override
     public CompletableFuture<Long> getAndIncrement() {
     public CompletableFuture<Long> getAndIncrement() {
         final MeteringAgent.Context timer = monitor.startTimer(GET_AND_INCREMENT);
         final MeteringAgent.Context timer = monitor.startTimer(GET_AND_INCREMENT);
         return getAndAdd(1L)
         return getAndAdd(1L)
-                .whenComplete((r, e) -> timer.stop());
+                .whenComplete((r, e) -> timer.stop(e));
     }
     }
 
 
     @Override
     @Override
     public CompletableFuture<Long> getAndAdd(long delta) {
     public CompletableFuture<Long> getAndAdd(long delta) {
         final MeteringAgent.Context timer = monitor.startTimer(GET_AND_ADD);
         final MeteringAgent.Context timer = monitor.startTimer(GET_AND_ADD);
         return database.counterGetAndAdd(name, delta)
         return database.counterGetAndAdd(name, delta)
-                       .whenComplete((r, e) -> timer.stop());
+                       .whenComplete((r, e) -> timer.stop(e));
     }
     }
 
 
     @Override
     @Override
     public CompletableFuture<Long> addAndGet(long delta) {
     public CompletableFuture<Long> addAndGet(long delta) {
         final MeteringAgent.Context timer = monitor.startTimer(ADD_AND_GET);
         final MeteringAgent.Context timer = monitor.startTimer(ADD_AND_GET);
         return database.counterAddAndGet(name, delta)
         return database.counterAddAndGet(name, delta)
-                       .whenComplete((r, e) -> timer.stop());
+                       .whenComplete((r, e) -> timer.stop(e));
     }
     }
 }
 }

@@ -193,14 +193,14 @@ public class DefaultAsyncConsistentMap<K, V>  implements AsyncConsistentMap<K, V
     public CompletableFuture<Integer> size() {
     public CompletableFuture<Integer> size() {
         final MeteringAgent.Context timer = monitor.startTimer(SIZE);
         final MeteringAgent.Context timer = monitor.startTimer(SIZE);
         return database.mapSize(name)
         return database.mapSize(name)
-                .whenComplete((r, e) -> timer.stop());
+                .whenComplete((r, e) -> timer.stop(e));
     }
     }
 
 
     @Override
     @Override
     public CompletableFuture<Boolean> isEmpty() {
     public CompletableFuture<Boolean> isEmpty() {
         final MeteringAgent.Context timer = monitor.startTimer(IS_EMPTY);
         final MeteringAgent.Context timer = monitor.startTimer(IS_EMPTY);
         return database.mapIsEmpty(name)
         return database.mapIsEmpty(name)
-                .whenComplete((r, e) -> timer.stop());
+                .whenComplete((r, e) -> timer.stop(e));
     }
     }
 
 
     @Override
     @Override
@@ -208,7 +208,7 @@ public class DefaultAsyncConsistentMap<K, V>  implements AsyncConsistentMap<K, V
         checkNotNull(key, ERROR_NULL_KEY);
         checkNotNull(key, ERROR_NULL_KEY);
         final MeteringAgent.Context timer = monitor.startTimer(CONTAINS_KEY);
         final MeteringAgent.Context timer = monitor.startTimer(CONTAINS_KEY);
         return database.mapContainsKey(name, keyCache.getUnchecked(key))
         return database.mapContainsKey(name, keyCache.getUnchecked(key))
-                .whenComplete((r, e) -> timer.stop());
+                .whenComplete((r, e) -> timer.stop(e));
     }
     }
 
 
     @Override
     @Override
@@ -216,7 +216,7 @@ public class DefaultAsyncConsistentMap<K, V>  implements AsyncConsistentMap<K, V
         checkNotNull(value, ERROR_NULL_VALUE);
         checkNotNull(value, ERROR_NULL_VALUE);
         final MeteringAgent.Context timer = monitor.startTimer(CONTAINS_VALUE);
         final MeteringAgent.Context timer = monitor.startTimer(CONTAINS_VALUE);
         return database.mapContainsValue(name, serializer.encode(value))
         return database.mapContainsValue(name, serializer.encode(value))
-                .whenComplete((r, e) -> timer.stop());
+                .whenComplete((r, e) -> timer.stop(e));
     }
     }
 
 
     @Override
     @Override
@@ -224,7 +224,7 @@ public class DefaultAsyncConsistentMap<K, V>  implements AsyncConsistentMap<K, V
         checkNotNull(key, ERROR_NULL_KEY);
         checkNotNull(key, ERROR_NULL_KEY);
         final MeteringAgent.Context timer = monitor.startTimer(GET);
         final MeteringAgent.Context timer = monitor.startTimer(GET);
         return database.mapGet(name, keyCache.getUnchecked(key))
         return database.mapGet(name, keyCache.getUnchecked(key))
-                .whenComplete((r, e) -> timer.stop())
+                .whenComplete((r, e) -> timer.stop(e))
                 .thenApply(v -> v != null ? v.map(serializer::decode) : null);
                 .thenApply(v -> v != null ? v.map(serializer::decode) : null);
     }
     }
 
 
@@ -235,7 +235,7 @@ public class DefaultAsyncConsistentMap<K, V>  implements AsyncConsistentMap<K, V
         checkNotNull(mappingFunction, "Mapping function cannot be null");
         checkNotNull(mappingFunction, "Mapping function cannot be null");
         final MeteringAgent.Context timer = monitor.startTimer(COMPUTE_IF_ABSENT);
         final MeteringAgent.Context timer = monitor.startTimer(COMPUTE_IF_ABSENT);
         return updateAndGet(key, Match.ifNull(), Match.any(), mappingFunction.apply(key))
         return updateAndGet(key, Match.ifNull(), Match.any(), mappingFunction.apply(key))
-                .whenComplete((r, e) -> timer.stop())
+                .whenComplete((r, e) -> timer.stop(e))
                 .thenApply(v -> v.newValue());
                 .thenApply(v -> v.newValue());
     }
     }
 
 
@@ -279,7 +279,7 @@ public class DefaultAsyncConsistentMap<K, V>  implements AsyncConsistentMap<K, V
             Match<V> valueMatcher = r1 == null ? Match.ifNull() : Match.any();
             Match<V> valueMatcher = r1 == null ? Match.ifNull() : Match.any();
             Match<Long> versionMatcher = r1 == null ? Match.any() : Match.ifValue(r1.version());
             Match<Long> versionMatcher = r1 == null ? Match.any() : Match.ifValue(r1.version());
             return updateAndGet(key, valueMatcher, versionMatcher, computedValue.get())
             return updateAndGet(key, valueMatcher, versionMatcher, computedValue.get())
-                    .whenComplete((r, e) -> timer.stop())
+                    .whenComplete((r, e) -> timer.stop(e))
                     .thenApply(v -> {
                     .thenApply(v -> {
                         if (v.updated()) {
                         if (v.updated()) {
                             return v.newValue();
                             return v.newValue();
@@ -296,7 +296,7 @@ public class DefaultAsyncConsistentMap<K, V>  implements AsyncConsistentMap<K, V
         checkNotNull(value, ERROR_NULL_VALUE);
         checkNotNull(value, ERROR_NULL_VALUE);
         final MeteringAgent.Context timer = monitor.startTimer(PUT);
         final MeteringAgent.Context timer = monitor.startTimer(PUT);
         return updateAndGet(key, Match.any(), Match.any(), value).thenApply(v -> v.oldValue())
         return updateAndGet(key, Match.any(), Match.any(), value).thenApply(v -> v.oldValue())
-                .whenComplete((r, e) -> timer.stop());
+                .whenComplete((r, e) -> timer.stop(e));
     }
     }
 
 
     @Override
     @Override
@@ -305,7 +305,7 @@ public class DefaultAsyncConsistentMap<K, V>  implements AsyncConsistentMap<K, V
         checkNotNull(value, ERROR_NULL_VALUE);
         checkNotNull(value, ERROR_NULL_VALUE);
         final MeteringAgent.Context timer = monitor.startTimer(PUT_AND_GET);
         final MeteringAgent.Context timer = monitor.startTimer(PUT_AND_GET);
         return updateAndGet(key, Match.any(), Match.any(), value).thenApply(v -> v.newValue())
         return updateAndGet(key, Match.any(), Match.any(), value).thenApply(v -> v.newValue())
-                .whenComplete((r, e) -> timer.stop());
+                .whenComplete((r, e) -> timer.stop(e));
     }
     }
 
 
     @Override
     @Override
@@ -313,7 +313,7 @@ public class DefaultAsyncConsistentMap<K, V>  implements AsyncConsistentMap<K, V
         checkNotNull(key, ERROR_NULL_KEY);
         checkNotNull(key, ERROR_NULL_KEY);
         final MeteringAgent.Context timer = monitor.startTimer(REMOVE);
         final MeteringAgent.Context timer = monitor.startTimer(REMOVE);
         return updateAndGet(key, Match.any(), Match.any(), null).thenApply(v -> v.oldValue())
         return updateAndGet(key, Match.any(), Match.any(), null).thenApply(v -> v.oldValue())
-                .whenComplete((r, e) -> timer.stop());
+                .whenComplete((r, e) -> timer.stop(e));
     }
     }
 
 
     @Override
     @Override
@@ -321,7 +321,7 @@ public class DefaultAsyncConsistentMap<K, V>  implements AsyncConsistentMap<K, V
         checkIfUnmodifiable();
         checkIfUnmodifiable();
         final MeteringAgent.Context timer = monitor.startTimer(CLEAR);
         final MeteringAgent.Context timer = monitor.startTimer(CLEAR);
         return database.mapClear(name).thenApply(this::unwrapResult)
         return database.mapClear(name).thenApply(this::unwrapResult)
-                .whenComplete((r, e) -> timer.stop());
+                .whenComplete((r, e) -> timer.stop(e));
     }
     }
 
 
     @Override
     @Override
@@ -332,14 +332,14 @@ public class DefaultAsyncConsistentMap<K, V>  implements AsyncConsistentMap<K, V
                         .stream()
                         .stream()
                         .map(this::dK)
                         .map(this::dK)
                         .collect(Collectors.toSet()))
                         .collect(Collectors.toSet()))
-                .whenComplete((r, e) -> timer.stop());
+                .whenComplete((r, e) -> timer.stop(e));
     }
     }
 
 
     @Override
     @Override
     public CompletableFuture<Collection<Versioned<V>>> values() {
     public CompletableFuture<Collection<Versioned<V>>> values() {
         final MeteringAgent.Context timer = monitor.startTimer(VALUES);
         final MeteringAgent.Context timer = monitor.startTimer(VALUES);
         return database.mapValues(name)
         return database.mapValues(name)
-                .whenComplete((r, e) -> timer.stop())
+                .whenComplete((r, e) -> timer.stop(e))
                 .thenApply(c -> c
                 .thenApply(c -> c
                         .stream()
                         .stream()
                         .map(v -> v.<V>map(serializer::decode))
                         .map(v -> v.<V>map(serializer::decode))
@@ -350,7 +350,7 @@ public class DefaultAsyncConsistentMap<K, V>  implements AsyncConsistentMap<K, V
     public CompletableFuture<Set<Entry<K, Versioned<V>>>> entrySet() {
     public CompletableFuture<Set<Entry<K, Versioned<V>>>> entrySet() {
         final MeteringAgent.Context timer = monitor.startTimer(ENTRY_SET);
         final MeteringAgent.Context timer = monitor.startTimer(ENTRY_SET);
         return database.mapEntrySet(name)
         return database.mapEntrySet(name)
-                .whenComplete((r, e) -> timer.stop())
+                .whenComplete((r, e) -> timer.stop(e))
                 .thenApply(s -> s
                 .thenApply(s -> s
                         .stream()
                         .stream()
                         .map(this::mapRawEntry)
                         .map(this::mapRawEntry)
@@ -363,7 +363,7 @@ public class DefaultAsyncConsistentMap<K, V>  implements AsyncConsistentMap<K, V
         checkNotNull(value, ERROR_NULL_VALUE);
         checkNotNull(value, ERROR_NULL_VALUE);
         final MeteringAgent.Context timer = monitor.startTimer(PUT_IF_ABSENT);
         final MeteringAgent.Context timer = monitor.startTimer(PUT_IF_ABSENT);
         return updateAndGet(key, Match.ifNull(), Match.any(), value)
         return updateAndGet(key, Match.ifNull(), Match.any(), value)
-                .whenComplete((r, e) -> timer.stop())
+                .whenComplete((r, e) -> timer.stop(e))
                 .thenApply(v -> v.oldValue());
                 .thenApply(v -> v.oldValue());
     }
     }
 
 
@@ -373,7 +373,7 @@ public class DefaultAsyncConsistentMap<K, V>  implements AsyncConsistentMap<K, V
         checkNotNull(value, ERROR_NULL_VALUE);
         checkNotNull(value, ERROR_NULL_VALUE);
         final MeteringAgent.Context timer = monitor.startTimer(REMOVE);
         final MeteringAgent.Context timer = monitor.startTimer(REMOVE);
         return updateAndGet(key, Match.ifValue(value), Match.any(), null)
         return updateAndGet(key, Match.ifValue(value), Match.any(), null)
-                .whenComplete((r, e) -> timer.stop())
+                .whenComplete((r, e) -> timer.stop(e))
                 .thenApply(v -> v.updated());
                 .thenApply(v -> v.updated());
     }
     }
 
 
@@ -382,7 +382,7 @@ public class DefaultAsyncConsistentMap<K, V>  implements AsyncConsistentMap<K, V
         checkNotNull(key, ERROR_NULL_KEY);
         checkNotNull(key, ERROR_NULL_KEY);
         final MeteringAgent.Context timer = monitor.startTimer(REMOVE);
         final MeteringAgent.Context timer = monitor.startTimer(REMOVE);
         return updateAndGet(key, Match.any(), Match.ifValue(version), null)
         return updateAndGet(key, Match.any(), Match.ifValue(version), null)
-                .whenComplete((r, e) -> timer.stop())
+                .whenComplete((r, e) -> timer.stop(e))
                 .thenApply(v -> v.updated());
                 .thenApply(v -> v.updated());
     }
     }
 
 
@@ -393,7 +393,7 @@ public class DefaultAsyncConsistentMap<K, V>  implements AsyncConsistentMap<K, V
         checkNotNull(newValue, ERROR_NULL_VALUE);
         checkNotNull(newValue, ERROR_NULL_VALUE);
         final MeteringAgent.Context timer = monitor.startTimer(REPLACE);
         final MeteringAgent.Context timer = monitor.startTimer(REPLACE);
         return updateAndGet(key, Match.ifValue(oldValue), Match.any(), newValue)
         return updateAndGet(key, Match.ifValue(oldValue), Match.any(), newValue)
-                .whenComplete((r, e) -> timer.stop())
+                .whenComplete((r, e) -> timer.stop(e))
                 .thenApply(v -> v.updated());
                 .thenApply(v -> v.updated());
     }
     }
 
 
@@ -401,7 +401,7 @@ public class DefaultAsyncConsistentMap<K, V>  implements AsyncConsistentMap<K, V
     public CompletableFuture<Boolean> replace(K key, long oldVersion, V newValue) {
     public CompletableFuture<Boolean> replace(K key, long oldVersion, V newValue) {
         final MeteringAgent.Context timer = monitor.startTimer(REPLACE);
         final MeteringAgent.Context timer = monitor.startTimer(REPLACE);
         return updateAndGet(key, Match.any(), Match.ifValue(oldVersion), newValue)
         return updateAndGet(key, Match.any(), Match.ifValue(oldVersion), newValue)
-                .whenComplete((r, e) -> timer.stop())
+                .whenComplete((r, e) -> timer.stop(e))
                 .thenApply(v -> v.updated());
                 .thenApply(v -> v.updated());
     }
     }
 
 

@@ -72,7 +72,7 @@ public class DefaultAtomicValue<V> implements AtomicValue<V> {
                 return valueMap.replace(name, serializer.encode(expect), serializer.encode(update));
                 return valueMap.replace(name, serializer.encode(expect), serializer.encode(update));
             }
             }
         } finally {
         } finally {
-            newTimer.stop();
+            newTimer.stop(null);
         }
         }
     }
     }
 
 
@@ -83,7 +83,7 @@ public class DefaultAtomicValue<V> implements AtomicValue<V> {
             Versioned<byte[]> rawValue = valueMap.get(name);
             Versioned<byte[]> rawValue = valueMap.get(name);
             return rawValue == null ? null : serializer.decode(rawValue.value());
             return rawValue == null ? null : serializer.decode(rawValue.value());
         } finally {
         } finally {
-            newTimer.stop();
+            newTimer.stop(null);
         }
         }
     }
     }
 
 
@@ -95,7 +95,7 @@ public class DefaultAtomicValue<V> implements AtomicValue<V> {
                     valueMap.remove(name) : valueMap.put(name, serializer.encode(value));
                     valueMap.remove(name) : valueMap.put(name, serializer.encode(value));
             return previousValue == null ? null : serializer.decode(previousValue.value());
             return previousValue == null ? null : serializer.decode(previousValue.value());
         } finally {
         } finally {
-            newTimer.stop();
+            newTimer.stop(null);
         }
         }
     }
     }
 
 

@@ -73,7 +73,7 @@ public class DefaultDistributedQueue<E>  implements DistributedQueue<E> {
     @Override
     @Override
     public long size() {
     public long size() {
         final MeteringAgent.Context timer = monitor.startTimer(SIZE);
         final MeteringAgent.Context timer = monitor.startTimer(SIZE);
-        return Futures.getUnchecked(database.queueSize(name).whenComplete((r, e) -> timer.stop()));
+        return Futures.getUnchecked(database.queueSize(name).whenComplete((r, e) -> timer.stop(e)));
     }
     }
 
 
     @Override
     @Override
@@ -81,14 +81,14 @@ public class DefaultDistributedQueue<E>  implements DistributedQueue<E> {
         checkNotNull(entry, ERROR_NULL_ENTRY);
         checkNotNull(entry, ERROR_NULL_ENTRY);
         final MeteringAgent.Context timer = monitor.startTimer(PUSH);
         final MeteringAgent.Context timer = monitor.startTimer(PUSH);
         Futures.getUnchecked(database.queuePush(name, serializer.encode(entry))
         Futures.getUnchecked(database.queuePush(name, serializer.encode(entry))
-                                     .whenComplete((r, e) -> timer.stop()));
+                                     .whenComplete((r, e) -> timer.stop(e)));
     }
     }
 
 
     @Override
     @Override
     public CompletableFuture<E> pop() {
     public CompletableFuture<E> pop() {
         final MeteringAgent.Context timer = monitor.startTimer(POP);
         final MeteringAgent.Context timer = monitor.startTimer(POP);
         return database.queuePop(name)
         return database.queuePop(name)
-                       .whenComplete((r, e) -> timer.stop())
+                       .whenComplete((r, e) -> timer.stop(e))
                        .thenCompose(v -> {
                        .thenCompose(v -> {
                            if (v != null) {
                            if (v != null) {
                                return CompletableFuture.completedFuture(serializer.decode(v));
                                return CompletableFuture.completedFuture(serializer.decode(v));
@@ -97,6 +97,7 @@ public class DefaultDistributedQueue<E>  implements DistributedQueue<E> {
                            pendingFutures.add(newPendingFuture);
                            pendingFutures.add(newPendingFuture);
                            return newPendingFuture;
                            return newPendingFuture;
                        });
                        });
+
     }
     }
 
 
     @Override
     @Override
@@ -104,7 +105,7 @@ public class DefaultDistributedQueue<E>  implements DistributedQueue<E> {
         final MeteringAgent.Context timer = monitor.startTimer(PEEK);
         final MeteringAgent.Context timer = monitor.startTimer(PEEK);
         return Futures.getUnchecked(database.queuePeek(name)
         return Futures.getUnchecked(database.queuePeek(name)
                                             .thenApply(v -> v != null ? serializer.<E>decode(v) : null)
                                             .thenApply(v -> v != null ? serializer.<E>decode(v) : null)
-                                            .whenComplete((r, e) -> timer.stop()));
+                                            .whenComplete((r, e) -> timer.stop(e)));
     }
     }
 
 
     public String name() {
     public String name() {

@@ -67,7 +67,7 @@ public class DefaultDistributedSet<E> implements DistributedSet<E> {
         try {
         try {
             return backingMap.size();
             return backingMap.size();
         } finally {
         } finally {
-            timer.stop();
+            timer.stop(null);
         }
         }
     }
     }
 
 
@@ -77,7 +77,7 @@ public class DefaultDistributedSet<E> implements DistributedSet<E> {
         try {
         try {
             return backingMap.isEmpty();
             return backingMap.isEmpty();
         } finally {
         } finally {
-            timer.stop();
+            timer.stop(null);
         }
         }
     }
     }
 
 
@@ -88,7 +88,7 @@ public class DefaultDistributedSet<E> implements DistributedSet<E> {
         try {
         try {
             return backingMap.containsKey((E) o);
             return backingMap.containsKey((E) o);
         } finally {
         } finally {
-            timer.stop();
+            timer.stop(null);
         }
         }
     }
     }
 
 
@@ -99,7 +99,7 @@ public class DefaultDistributedSet<E> implements DistributedSet<E> {
         try {
         try {
             return backingMap.keySet().iterator();
             return backingMap.keySet().iterator();
         } finally {
         } finally {
-            timer.stop();
+            timer.stop(null);
         }
         }
     }
     }
 
 
@@ -109,7 +109,7 @@ public class DefaultDistributedSet<E> implements DistributedSet<E> {
         try {
         try {
             return backingMap.keySet().stream().toArray();
             return backingMap.keySet().stream().toArray();
         } finally {
         } finally {
-            timer.stop();
+            timer.stop(null);
         }
         }
     }
     }
 
 
@@ -119,7 +119,7 @@ public class DefaultDistributedSet<E> implements DistributedSet<E> {
         try {
         try {
             return backingMap.keySet().stream().toArray(size -> a);
             return backingMap.keySet().stream().toArray(size -> a);
         } finally {
         } finally {
-            timer.stop();
+            timer.stop(null);
         }
         }
     }
     }
 
 
@@ -129,7 +129,7 @@ public class DefaultDistributedSet<E> implements DistributedSet<E> {
         try {
         try {
             return backingMap.putIfAbsent(e, true) == null;
             return backingMap.putIfAbsent(e, true) == null;
         } finally {
         } finally {
-            timer.stop();
+            timer.stop(null);
         }
         }
     }
     }
 
 
@@ -140,7 +140,7 @@ public class DefaultDistributedSet<E> implements DistributedSet<E> {
         try {
         try {
             return backingMap.remove((E) o) != null;
             return backingMap.remove((E) o) != null;
         } finally {
         } finally {
-            timer.stop();
+            timer.stop(null);
         }
         }
     }
     }
 
 
@@ -151,7 +151,7 @@ public class DefaultDistributedSet<E> implements DistributedSet<E> {
            return c.stream()
            return c.stream()
                 .allMatch(this::contains);
                 .allMatch(this::contains);
         } finally {
         } finally {
-            timer.stop();
+            timer.stop(null);
         }
         }
     }
     }
 
 
@@ -164,7 +164,7 @@ public class DefaultDistributedSet<E> implements DistributedSet<E> {
                 .reduce(Boolean::logicalOr)
                 .reduce(Boolean::logicalOr)
                 .orElse(false);
                 .orElse(false);
         } finally {
         } finally {
-            timer.stop();
+            timer.stop(null);
         }
         }
     }
     }
 
 
@@ -180,7 +180,7 @@ public class DefaultDistributedSet<E> implements DistributedSet<E> {
                 .reduce(Boolean::logicalOr)
                 .reduce(Boolean::logicalOr)
                 .orElse(false);
                 .orElse(false);
         } finally {
         } finally {
-            timer.stop();
+            timer.stop(null);
         }
         }
     }
     }
 
 
@@ -196,7 +196,7 @@ public class DefaultDistributedSet<E> implements DistributedSet<E> {
                 .reduce(Boolean::logicalOr)
                 .reduce(Boolean::logicalOr)
                 .orElse(false);
                 .orElse(false);
         } finally {
         } finally {
-            timer.stop();
+            timer.stop(null);
         }
         }
     }
     }
 
 
@@ -206,7 +206,7 @@ public class DefaultDistributedSet<E> implements DistributedSet<E> {
         try {
         try {
             backingMap.clear();
             backingMap.clear();
         } finally {
         } finally {
-            timer.stop();
+            timer.stop(null);
         }
         }
     }
     }
 
 

@@ -15,6 +15,7 @@
  */
  */
 package org.onosproject.store.consistent.impl;
 package org.onosproject.store.consistent.impl;
 
 
+import com.codahale.metrics.Counter;
 import com.codahale.metrics.Timer;
 import com.codahale.metrics.Timer;
 import com.google.common.collect.Maps;
 import com.google.common.collect.Maps;
 import org.onlab.metrics.MetricsComponent;
 import org.onlab.metrics.MetricsComponent;
@@ -32,6 +33,8 @@ import static com.google.common.base.Preconditions.checkNotNull;
  */
  */
 public class MeteringAgent {
 public class MeteringAgent {
 
 
+    private Counter exceptionCounter;
+    private Counter perObjExceptionCounter;
     private MetricsService metricsService;
     private MetricsService metricsService;
     private MetricsComponent metricsComponent;
     private MetricsComponent metricsComponent;
     private MetricsFeature metricsFeature;
     private MetricsFeature metricsFeature;
@@ -63,6 +66,8 @@ public class MeteringAgent {
             this.wildcard = metricsComponent.registerFeature("*");
             this.wildcard = metricsComponent.registerFeature("*");
             this.perObjTimer = metricsService.createTimer(metricsComponent, metricsFeature, "*");
             this.perObjTimer = metricsService.createTimer(metricsComponent, metricsFeature, "*");
             this.perPrimitiveTimer = metricsService.createTimer(metricsComponent, wildcard, "*");
             this.perPrimitiveTimer = metricsService.createTimer(metricsComponent, wildcard, "*");
+            this.perObjExceptionCounter = metricsService.createCounter(metricsComponent, metricsFeature, "exceptions");
+            this.exceptionCounter = metricsService.createCounter(metricsComponent, wildcard, "exceptions");
         }
         }
     }
     }
 
 
@@ -103,11 +108,13 @@ public class MeteringAgent {
 
 
         /**
         /**
          * Stops timer given a specific context and updates all related metrics.
          * Stops timer given a specific context and updates all related metrics.
+         * @param e
          */
          */
-        public void stop() {
+        public void stop(Throwable e) {
             if (!activated) {
             if (!activated) {
                 return;
                 return;
             }
             }
+            if (e == null) {
                 //Stop and updates timer with specific measurements per map, per operation
                 //Stop and updates timer with specific measurements per map, per operation
                 final long time = context.stop();
                 final long time = context.stop();
                 //updates timer with aggregated measurements per map
                 //updates timer with aggregated measurements per map
@@ -116,6 +123,10 @@ public class MeteringAgent {
                 perObjTimer.update(time, TimeUnit.NANOSECONDS);
                 perObjTimer.update(time, TimeUnit.NANOSECONDS);
                 //updates timer with aggregated measurements per all Consistent Maps
                 //updates timer with aggregated measurements per all Consistent Maps
                 perPrimitiveTimer.update(time, TimeUnit.NANOSECONDS);
                 perPrimitiveTimer.update(time, TimeUnit.NANOSECONDS);
+            } else {
+                exceptionCounter.inc();
+                perObjExceptionCounter.inc();
+            }
         }
         }
     }
     }