ONOS-2456 Added usage metrics to Atomic Counter and Distributed Queue plus refactored the code a bit

Refactored code plus instrumented AtomicValue and DistributedSet

Change-Id: I9c5f7c9f23d530131f15d3c98250ea33238dd2ec

@@ -59,6 +59,14 @@ public interface AtomicCounterBuilder {
     AtomicCounterBuilder withRetryOnFailure();
 
     /**
+     * Instantiates Metering service to gather usage and performance metrics.
+     * By default, usage data will be stored.
+     *
+     * @return this AtomicCounterBuilder
+     */
+    AtomicCounterBuilder withMeteringDisabled();
+
+    /**
      * Sets the executor service to use for retrying failed operations.
      * <p>
      * Note: Must be set when retries are enabled

@@ -60,6 +60,14 @@ public interface AtomicValueBuilder<V> {
     AtomicValueBuilder<V> withPartitionsDisabled();
 
     /**
+     * Instantiates Metering service to gather usage and performance metrics.
+     * By default, usage data will be stored.
+     *
+     * @return this AtomicValueBuilder for method chaining
+     */
+    AtomicValueBuilder<V> withMeteringDisabled();
+
+    /**
      * Builds a AtomicValue based on the configuration options
      * supplied to this builder.
      *

@@ -105,6 +105,14 @@ public interface ConsistentMapBuilder<K, V> {
     ConsistentMapBuilder<K, V> withPurgeOnUninstall();
 
     /**
+     * Instantiates Metering service to gather usage and performance metrics.
+     * By default, usage data will be stored.
+     *
+     * @return this ConsistentMapBuilder
+     */
+    ConsistentMapBuilder<K, V> withMeteringDisabled();
+
+    /**
      * Builds an consistent map based on the configuration options
      * supplied to this builder.
      *

@@ -51,6 +51,14 @@ public interface DistributedQueueBuilder<E> {
     DistributedQueueBuilder<E> withSerializer(Serializer serializer);
 
     /**
+     *
+     *
+     * @return this DistributedQueueBuilder for method chaining
+     */
+    DistributedQueueBuilder<E> withMeteringDisabled();
+
+
+    /**
      * Disables persistence of queues entries.
      * <p>
      * When persistence is disabled, a full cluster restart will wipe out all

@@ -92,6 +92,13 @@ public interface DistributedSetBuilder<E> {
     DistributedSetBuilder<E> withPartitionsDisabled();
 
     /**
+     * Instantiate Metrics service to gather usage and performance metrics.
+     * By default usage information is enabled
+     * @return this DistributedSetBuilder
+     */
+    DistributedSetBuilder<E> withMeteringDisabled();
+
+    /**
      * Purges set contents when the application owning the set is uninstalled.
      * <p>
      * When this option is enabled, the caller must provide a applicationId via

@@ -247,6 +247,11 @@ public final class TestConsistentMap<K, V> extends ConsistentMapAdapter<K, V> {
         }
 
         @Override
+        public ConsistentMapBuilder<K, V> withMeteringDisabled() {
+            return this;
+        }
+
+        @Override
         public ConsistentMap<K, V> build() {
             return new TestConsistentMap<>(mapName);
         }

@@ -15,20 +15,15 @@
  */
 package org.onosproject.store.consistent.impl;
 
+import org.onosproject.store.service.AsyncAtomicCounter;
+import org.slf4j.Logger;
+
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
 import java.util.function.BiFunction;
 
-import org.onosproject.store.service.AsyncAtomicCounter;
-
-
-
-
-
-import org.slf4j.Logger;
-
-import static com.google.common.base.Preconditions.*;
+import static com.google.common.base.Preconditions.checkNotNull;
 import static org.slf4j.LoggerFactory.getLogger;
 
 /**
@@ -46,41 +41,61 @@ public class DefaultAsyncAtomicCounter implements AsyncAtomicCounter {
     // TODO: configure delay via builder
     private static final int DELAY_BETWEEN_RETRY_SEC = 1;
     private final Logger log = getLogger(getClass());
+    private final MeteringAgent monitor;
+
+    private static final String PRIMITIVE_NAME = "atomicCounter";
+    private static final String INCREMENT_AND_GET = "incrementAndGet";
+    private static final String GET_AND_INCREMENT = "getAndIncrement";
+    private static final String GET_AND_ADD = "getAndAdd";
+    private static final String ADD_AND_GET = "addAndGet";
+    private static final String GET = "get";
 
     public DefaultAsyncAtomicCounter(String name,
                                      Database database,
                                      boolean retryOnException,
+                                     boolean meteringEnabled,
                                      ScheduledExecutorService retryExecutor) {
         this.name = checkNotNull(name);
         this.database = checkNotNull(database);
         this.retryOnFailure = retryOnException;
         this.retryExecutor = retryExecutor;
+        this.monitor = new MeteringAgent(PRIMITIVE_NAME, name, meteringEnabled);
     }
 
     @Override
     public CompletableFuture<Long> incrementAndGet() {
-        return addAndGet(1L);
+        final MeteringAgent.Context timer = monitor.startTimer(INCREMENT_AND_GET);
+        return addAndGet(1L)
+                .whenComplete((r, e) -> timer.stop());
     }
 
     @Override
     public CompletableFuture<Long> get() {
-        return database.counterGet(name);
+        final MeteringAgent.Context timer = monitor.startTimer(GET);
+        return database.counterGet(name)
+                .whenComplete((r, e) -> timer.stop());
     }
 
     @Override
     public CompletableFuture<Long> getAndIncrement() {
-        return getAndAdd(1L);
+        final MeteringAgent.Context timer = monitor.startTimer(GET_AND_INCREMENT);
+        return getAndAdd(1L)
+                .whenComplete((r, e) -> timer.stop());
     }
 
     @Override
     public CompletableFuture<Long> getAndAdd(long delta) {
+        final MeteringAgent.Context timer = monitor.startTimer(GET_AND_ADD);
         CompletableFuture<Long> result = database.counterGetAndAdd(name, delta);
         if (!retryOnFailure) {
-            return result;
+            return result
+                    .whenComplete((r, e) -> timer.stop());
         }
 
         CompletableFuture<Long> future = new CompletableFuture<>();
         return result.whenComplete((r, e) -> {
+            timer.stop();
+            // TODO : Account for retries
             if (e != null) {
                 log.warn("getAndAdd failed due to {}. Will retry", e.getMessage());
                 retryExecutor.schedule(new RetryTask(database::counterGetAndAdd, delta, future),
@@ -94,13 +109,17 @@ public class DefaultAsyncAtomicCounter implements AsyncAtomicCounter {
 
     @Override
     public CompletableFuture<Long> addAndGet(long delta) {
+        final MeteringAgent.Context timer = monitor.startTimer(ADD_AND_GET);
         CompletableFuture<Long> result = database.counterAddAndGet(name, delta);
         if (!retryOnFailure) {
-            return result;
+            return result
+                    .whenComplete((r, e) -> timer.stop());
         }
 
         CompletableFuture<Long> future = new CompletableFuture<>();
         return result.whenComplete((r, e) -> {
+            timer.stop();
+            // TODO : Account for retries
             if (e != null) {
                 log.warn("addAndGet failed due to {}. Will retry", e.getMessage());
                 retryExecutor.schedule(new RetryTask(database::counterAddAndGet, delta, future),

@@ -15,16 +15,16 @@
  */
 package org.onosproject.store.consistent.impl;
 
+import org.onosproject.store.service.AsyncAtomicCounter;
+import org.onosproject.store.service.AtomicCounter;
+import org.onosproject.store.service.StorageException;
+
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
 
-import org.onosproject.store.service.AsyncAtomicCounter;
-import org.onosproject.store.service.AtomicCounter;
-import org.onosproject.store.service.StorageException;
-
 /**
  * Default implementation for a distributed AtomicCounter backed by
  * partitioned Raft DB.
@@ -40,8 +40,9 @@ public class DefaultAtomicCounter implements AtomicCounter {
     public DefaultAtomicCounter(String name,
                                 Database database,
                                 boolean retryOnException,
+                                boolean meteringEnabled,
                                 ScheduledExecutorService retryExecutor) {
-        asyncCounter = new DefaultAsyncAtomicCounter(name, database, retryOnException, retryExecutor);
+        asyncCounter = new DefaultAsyncAtomicCounter(name, database, retryOnException, meteringEnabled, retryExecutor);
     }
 
     @Override

@@ -15,12 +15,12 @@
  */
 package org.onosproject.store.consistent.impl;
 
-import java.util.concurrent.ScheduledExecutorService;
-
 import org.onosproject.store.service.AsyncAtomicCounter;
 import org.onosproject.store.service.AtomicCounter;
 import org.onosproject.store.service.AtomicCounterBuilder;
 
+import java.util.concurrent.ScheduledExecutorService;
+
 import static com.google.common.base.Preconditions.checkArgument;
 
 /**
@@ -33,6 +33,7 @@ public class DefaultAtomicCounterBuilder implements AtomicCounterBuilder {
     private final Database partitionedDatabase;
     private final Database inMemoryDatabase;
     private boolean retryOnFailure = false;
+    private boolean metering = true;
     private ScheduledExecutorService retryExecutor = null;
 
     public DefaultAtomicCounterBuilder(Database inMemoryDatabase, Database partitionedDatabase) {
@@ -57,14 +58,14 @@ public class DefaultAtomicCounterBuilder implements AtomicCounterBuilder {
     public AtomicCounter build() {
         validateInputs();
         Database database = partitionsEnabled ? partitionedDatabase : inMemoryDatabase;
-        return new DefaultAtomicCounter(name, database, retryOnFailure, retryExecutor);
+        return new DefaultAtomicCounter(name, database, retryOnFailure, metering, retryExecutor);
     }
 
     @Override
     public AsyncAtomicCounter buildAsyncCounter() {
         validateInputs();
         Database database = partitionsEnabled ? partitionedDatabase : inMemoryDatabase;
-        return new DefaultAsyncAtomicCounter(name, database, retryOnFailure, retryExecutor);
+        return new DefaultAsyncAtomicCounter(name, database, retryOnFailure, metering, retryExecutor);
     }
 
     @Override
@@ -74,6 +75,12 @@ public class DefaultAtomicCounterBuilder implements AtomicCounterBuilder {
     }
 
     @Override
+    public AtomicCounterBuilder withMeteringDisabled() {
+        metering = false;
+        return this;
+    }
+
+    @Override
     public AtomicCounterBuilder withRetryExecutor(ScheduledExecutorService executor) {
         this.retryExecutor = executor;
         return this;

@@ -15,9 +15,6 @@
  */
 package org.onosproject.store.consistent.impl;
 
-import java.util.Set;
-import java.util.concurrent.CopyOnWriteArraySet;
-
 import org.onosproject.store.service.AtomicValue;
 import org.onosproject.store.service.AtomicValueEvent;
 import org.onosproject.store.service.AtomicValueEventListener;
@@ -27,6 +24,9 @@ import org.onosproject.store.service.MapEventListener;
 import org.onosproject.store.service.Serializer;
 import org.onosproject.store.service.Versioned;
 
+import java.util.Set;
+import java.util.concurrent.CopyOnWriteArraySet;
+
 /**
  * Default implementation of AtomicValue.
  *
@@ -39,17 +39,27 @@ public class DefaultAtomicValue<V> implements AtomicValue<V> {
     private final String name;
     private final Serializer serializer;
     private final MapEventListener<String, byte[]> mapEventListener = new InternalMapEventListener();
+    private final MeteringAgent monitor;
+
+    private static final String COMPONENT_NAME = "atomicValue";
+    private static final String GET = "get";
+    private static final String GET_AND_SET = "getAndSet";
+    private static final String COMPARE_AND_SET = "compareAndSet";
 
     public DefaultAtomicValue(ConsistentMap<String, byte[]> valueMap,
                               String name,
+                              boolean meteringEnabled,
                               Serializer serializer) {
         this.valueMap = valueMap;
         this.name = name;
         this.serializer = serializer;
+        this.monitor = new MeteringAgent(COMPONENT_NAME, name, meteringEnabled);
     }
 
     @Override
     public boolean compareAndSet(V expect, V update) {
+        final MeteringAgent.Context newTimer = monitor.startTimer(COMPARE_AND_SET);
+        try {
             if (expect == null) {
                 if (update == null) {
                     return true;
@@ -61,19 +71,32 @@ public class DefaultAtomicValue<V> implements AtomicValue<V> {
                 }
                 return valueMap.replace(name, serializer.encode(expect), serializer.encode(update));
             }
+        } finally {
+            newTimer.stop();
+        }
     }
 
     @Override
     public V get() {
+        final MeteringAgent.Context newTimer = monitor.startTimer(GET);
+        try {
             Versioned<byte[]> rawValue = valueMap.get(name);
             return rawValue == null ? null : serializer.decode(rawValue.value());
+        } finally {
+            newTimer.stop();
+        }
     }
 
     @Override
     public V getAndSet(V value) {
+        final MeteringAgent.Context newTimer = monitor.startTimer(GET_AND_SET);
+        try {
             Versioned<byte[]> previousValue = value == null ?
                     valueMap.remove(name) : valueMap.put(name, serializer.encode(value));
             return previousValue == null ? null : serializer.decode(previousValue.value());
+        } finally {
+            newTimer.stop();
+        }
     }
 
     @Override

@@ -31,10 +31,12 @@ public class DefaultAtomicValueBuilder<V> implements AtomicValueBuilder<V> {
     private Serializer serializer;
     private String name;
     private ConsistentMapBuilder<String, byte[]> mapBuilder;
+    private boolean metering = true;
 
     public DefaultAtomicValueBuilder(DatabaseManager manager) {
         mapBuilder = manager.<String, byte[]>consistentMapBuilder()
                             .withName("onos-atomic-values")
+                            .withMeteringDisabled()
                             .withSerializer(Serializer.using(KryoNamespaces.BASIC));
     }
 
@@ -57,7 +59,13 @@ public class DefaultAtomicValueBuilder<V> implements AtomicValueBuilder<V> {
     }
 
     @Override
+    public AtomicValueBuilder<V> withMeteringDisabled() {
+        metering = false;
+        return this;
+    }
+
+    @Override
     public AtomicValue<V> build() {
-        return new DefaultAtomicValue<>(mapBuilder.build(), name, serializer);
+        return new DefaultAtomicValue<>(mapBuilder.build(), name, metering, serializer);
     }
 }
\ No newline at end of file

@@ -15,15 +15,15 @@
  */
 package org.onosproject.store.consistent.impl;
 
-import static com.google.common.base.Preconditions.checkArgument;
-import static com.google.common.base.Preconditions.checkState;
-
 import org.onosproject.core.ApplicationId;
 import org.onosproject.store.service.AsyncConsistentMap;
 import org.onosproject.store.service.ConsistentMap;
 import org.onosproject.store.service.ConsistentMapBuilder;
 import org.onosproject.store.service.Serializer;
 
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkState;
+
 /**
  * Default Consistent Map builder.
  *
@@ -38,6 +38,7 @@ public class DefaultConsistentMapBuilder<K, V> implements ConsistentMapBuilder<K
     private boolean purgeOnUninstall = false;
     private boolean partitionsEnabled = true;
     private boolean readOnly = false;
+    private boolean metering = true;
     private final DatabaseManager manager;
 
     public DefaultConsistentMapBuilder(DatabaseManager manager) {
@@ -65,6 +66,12 @@ public class DefaultConsistentMapBuilder<K, V> implements ConsistentMapBuilder<K
     }
 
     @Override
+    public ConsistentMapBuilder<K, V> withMeteringDisabled() {
+        metering = false;
+        return this;
+    }
+
+    @Override
     public ConsistentMapBuilder<K, V> withSerializer(Serializer serializer) {
         checkArgument(serializer != null);
         this.serializer = serializer;
@@ -109,7 +116,8 @@ public class DefaultConsistentMapBuilder<K, V> implements ConsistentMapBuilder<K
                 partitionsEnabled ? manager.partitionedDatabase : manager.inMemoryDatabase,
                 serializer,
                 readOnly,
-                purgeOnUninstall);
+                purgeOnUninstall,
+                metering);
         return manager.registerMap(asyncMap);
     }
 }
\ No newline at end of file

@@ -15,18 +15,17 @@
  */
 package org.onosproject.store.consistent.impl;
 
-import static com.google.common.base.Preconditions.checkNotNull;
+import com.google.common.collect.Sets;
+import com.google.common.util.concurrent.Futures;
+import org.onosproject.cluster.NodeId;
+import org.onosproject.store.service.DistributedQueue;
+import org.onosproject.store.service.Serializer;
 
 import java.util.Set;
 import java.util.concurrent.CompletableFuture;
 import java.util.function.Consumer;
 
-import org.onosproject.cluster.NodeId;
-import org.onosproject.store.service.DistributedQueue;
-import org.onosproject.store.service.Serializer;
-
-import com.google.common.collect.Sets;
-import com.google.common.util.concurrent.Futures;
+import static com.google.common.base.Preconditions.checkNotNull;
 
 /**
  * DistributedQueue implementation that provides FIFO ordering semantics.
@@ -42,35 +41,56 @@ public class DefaultDistributedQueue<E> implements DistributedQueue<E> {
     private final Set<CompletableFuture<E>> pendingFutures = Sets.newIdentityHashSet();
     private final Consumer<Set<NodeId>> notifyConsumers;
 
+    private static final String PRIMITIVE_NAME = "distributedQueue";
+    private static final String SIZE = "size";
+    private static final String PUSH = "push";
+    private static final String POP = "pop";
+    private static final String PEEK = "peek";
+
     private static final String ERROR_NULL_ENTRY = "Null entries are not allowed";
+    private final MeteringAgent monitor;
 
     public DefaultDistributedQueue(String name,
                                    Database database,
                                    Serializer serializer,
                                    NodeId localNodeId,
+                                   boolean meteringEnabled,
                                    Consumer<Set<NodeId>> notifyConsumers) {
         this.name = checkNotNull(name, "queue name cannot be null");
         this.database = checkNotNull(database, "database cannot be null");
         this.serializer = checkNotNull(serializer, "serializer cannot be null");
         this.localNodeId = localNodeId;
         this.notifyConsumers = notifyConsumers;
+        this.monitor = new MeteringAgent(PRIMITIVE_NAME, name, meteringEnabled);
+
     }
 
     @Override
     public long size() {
+        final MeteringAgent.Context timer = monitor.startTimer(SIZE);
+        try {
             return Futures.getUnchecked(database.queueSize(name));
+        } finally {
+            timer.stop();
+        }
     }
 
     @Override
     public void push(E entry) {
+        final MeteringAgent.Context timer = monitor.startTimer(PUSH);
+        try {
             checkNotNull(entry, ERROR_NULL_ENTRY);
             Futures.getUnchecked(database.queuePush(name, serializer.encode(entry))
                                          .thenAccept(notifyConsumers)
                                          .thenApply(v -> null));
+        } finally {
+            timer.stop();
+        }
     }
 
     @Override
     public CompletableFuture<E> pop() {
+        final MeteringAgent.Context timer = monitor.startTimer(POP);
         return database.queuePop(name, localNodeId)
                        .thenCompose(v -> {
                            if (v != null) {
@@ -80,13 +100,19 @@ public class DefaultDistributedQueue<E> implements DistributedQueue<E> {
                                pendingFutures.add(newPendingFuture);
                                return newPendingFuture;
                            }
-                       });
+                       })
+                .whenComplete((r, e) -> timer.stop());
     }
 
     @Override
     public E peek() {
+        final MeteringAgent.Context timer = monitor.startTimer(PEEK);
+        try {
             return Futures.getUnchecked(database.queuePeek(name)
                                                 .thenApply(v -> v != null ? serializer.decode(v) : null));
+        } finally {
+            timer.stop();
+        }
     }
 
     public String name() {

@@ -15,18 +15,17 @@
  */
 package org.onosproject.store.consistent.impl;
 
-import static com.google.common.base.Preconditions.checkArgument;
-import static com.google.common.base.Preconditions.checkState;
-
-import java.util.Set;
-import java.util.function.Consumer;
-
+import com.google.common.base.Charsets;
 import org.onosproject.cluster.NodeId;
 import org.onosproject.store.service.DistributedQueue;
 import org.onosproject.store.service.DistributedQueueBuilder;
 import org.onosproject.store.service.Serializer;
 
-import com.google.common.base.Charsets;
+import java.util.Set;
+import java.util.function.Consumer;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkState;
 
 /**
  * Default implementation of a {@code DistributedQueueBuilder}.
@@ -39,6 +38,7 @@ public class DefaultDistributedQueueBuilder<E> implements DistributedQueueBuilde
     private String name;
     private boolean persistenceEnabled = true;
     private final DatabaseManager databaseManager;
+    private boolean metering = true;
 
     public DefaultDistributedQueueBuilder(
             DatabaseManager databaseManager) {
@@ -60,6 +60,12 @@ public class DefaultDistributedQueueBuilder<E> implements DistributedQueueBuilde
     }
 
     @Override
+    public DistributedQueueBuilder<E> withMeteringDisabled() {
+        metering = false;
+        return this;
+    }
+
+    @Override
     public DistributedQueueBuilder<E> withPersistenceDisabled() {
         persistenceEnabled = false;
         return this;
@@ -81,6 +87,7 @@ public class DefaultDistributedQueueBuilder<E> implements DistributedQueueBuilde
                 persistenceEnabled ? databaseManager.partitionedDatabase : databaseManager.inMemoryDatabase,
                 serializer,
                 databaseManager.localNodeId,
+                metering,
                 notifyOthers);
         databaseManager.registerQueue(queue);
         return queue;

@@ -15,11 +15,8 @@
  */
 package org.onosproject.store.consistent.impl;
 
-import java.util.Collection;
-import java.util.Iterator;
-import java.util.Map;
-import java.util.Set;
-
+import com.google.common.collect.Maps;
+import com.google.common.collect.Sets;
 import org.onosproject.store.service.ConsistentMap;
 import org.onosproject.store.service.DistributedSet;
 import org.onosproject.store.service.MapEvent;
@@ -27,8 +24,10 @@ import org.onosproject.store.service.MapEventListener;
 import org.onosproject.store.service.SetEvent;
 import org.onosproject.store.service.SetEventListener;
 
-import com.google.common.collect.Maps;
-import com.google.common.collect.Sets;
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Set;
 
 /**
  * Implementation of distributed set that is backed by a ConsistentMap.
@@ -37,73 +36,142 @@ import com.google.common.collect.Sets;
  */
 public class DefaultDistributedSet<E> implements DistributedSet<E> {
 
+    private static final String CONTAINS = "contains";
+    private static final String PRIMITIVE_NAME = "distributedSet";
+    private static final String SIZE = "size";
+    private static final String IS_EMPTY = "isEmpty";
+    private static final String ITERATOR = "iterator";
+    private static final String TO_ARRAY = "toArray";
+    private static final String ADD = "add";
+    private static final String REMOVE = "remove";
+    private static final String CONTAINS_ALL = "containsAll";
+    private static final String ADD_ALL = "addAll";
+    private static final String RETAIN_ALL = "retainAll";
+    private static final String REMOVE_ALL = "removeAll";
+    private static final String CLEAR = "clear";
+
     private final String name;
     private final ConsistentMap<E, Boolean> backingMap;
     private final Map<SetEventListener<E>, MapEventListener<E, Boolean>> listenerMapping = Maps.newIdentityHashMap();
+    private final MeteringAgent monitor;
 
-    public DefaultDistributedSet(String name, ConsistentMap<E, Boolean> backingMap) {
+    public DefaultDistributedSet(String name, boolean meteringEnabled, ConsistentMap<E, Boolean> backingMap) {
         this.name = name;
         this.backingMap = backingMap;
+        monitor = new MeteringAgent(PRIMITIVE_NAME, name, meteringEnabled);
     }
 
     @Override
     public int size() {
+        final MeteringAgent.Context timer = monitor.startTimer(SIZE);
+        try {
             return backingMap.size();
+        } finally {
+            timer.stop();
+        }
     }
 
     @Override
     public boolean isEmpty() {
+        final MeteringAgent.Context timer = monitor.startTimer(IS_EMPTY);
+        try {
             return backingMap.isEmpty();
+        } finally {
+            timer.stop();
+        }
     }
 
     @SuppressWarnings("unchecked")
     @Override
     public boolean contains(Object o) {
+        final MeteringAgent.Context timer = monitor.startTimer(CONTAINS);
+        try {
             return backingMap.containsKey((E) o);
+        } finally {
+            timer.stop();
+        }
     }
 
     @Override
     public Iterator<E> iterator() {
+        final MeteringAgent.Context timer = monitor.startTimer(ITERATOR);
+        //Do we have to measure this guy?
+        try {
             return backingMap.keySet().iterator();
+        } finally {
+            timer.stop();
+        }
     }
 
     @Override
     public Object[] toArray() {
+        final MeteringAgent.Context timer = monitor.startTimer(TO_ARRAY);
+        try {
             return backingMap.keySet().stream().toArray();
+        } finally {
+            timer.stop();
+        }
     }
 
     @Override
     public <T> T[] toArray(T[] a) {
+        final MeteringAgent.Context timer = monitor.startTimer(TO_ARRAY);
+        try {
             return backingMap.keySet().stream().toArray(size -> a);
+        } finally {
+            timer.stop();
+        }
     }
 
     @Override
     public boolean add(E e) {
+        final MeteringAgent.Context timer = monitor.startTimer(ADD);
+        try {
             return backingMap.putIfAbsent(e, true) == null;
+        } finally {
+            timer.stop();
+        }
     }
 
     @SuppressWarnings("unchecked")
     @Override
     public boolean remove(Object o) {
+        final MeteringAgent.Context timer = monitor.startTimer(REMOVE);
+        try {
             return backingMap.remove((E) o) != null;
+        } finally {
+            timer.stop();
+        }
     }
 
     @Override
     public boolean containsAll(Collection<?> c) {
+        final MeteringAgent.Context timer = monitor.startTimer(CONTAINS_ALL);
+        try {
            return c.stream()
                 .allMatch(this::contains);
+        } finally {
+            timer.stop();
+        }
     }
 
     @Override
     public boolean addAll(Collection<? extends E> c) {
+        final MeteringAgent.Context timer = monitor.startTimer(ADD_ALL);
+        try {
             return c.stream()
                 .map(this::add)
                 .reduce(Boolean::logicalOr)
                 .orElse(false);
+        } finally {
+            timer.stop();
+        }
     }
 
     @Override
     public boolean retainAll(Collection<?> c) {
+        final MeteringAgent.Context timer = monitor.startTimer(RETAIN_ALL);
+        try {
             Set<?> retainSet = Sets.newHashSet(c);
             return backingMap.keySet()
                 .stream()
@@ -111,10 +179,15 @@ public class DefaultDistributedSet<E> implements DistributedSet<E> {
                 .map(this::remove)
                 .reduce(Boolean::logicalOr)
                 .orElse(false);
+        } finally {
+            timer.stop();
+        }
     }
 
     @Override
     public boolean removeAll(Collection<?> c) {
+        final MeteringAgent.Context timer = monitor.startTimer(REMOVE_ALL);
+        try {
             Set<?> removeSet = Sets.newHashSet(c);
             return backingMap.keySet()
                 .stream()
@@ -122,11 +195,19 @@ public class DefaultDistributedSet<E> implements DistributedSet<E> {
                 .map(this::remove)
                 .reduce(Boolean::logicalOr)
                 .orElse(false);
+        } finally {
+            timer.stop();
+        }
     }
 
     @Override
     public void clear() {
+        final MeteringAgent.Context timer = monitor.startTimer(CLEAR);
+        try {
             backingMap.clear();
+        } finally {
+            timer.stop();
+        }
     }
 
     @Override

@@ -30,9 +30,11 @@ public class DefaultDistributedSetBuilder<E> implements DistributedSetBuilder<E>
 
     private String name;
     private ConsistentMapBuilder<E, Boolean>  mapBuilder;
+    private boolean metering = true;
 
     public DefaultDistributedSetBuilder(DatabaseManager manager) {
         this.mapBuilder = manager.consistentMapBuilder();
+        mapBuilder.withMeteringDisabled();
     }
 
     @Override
@@ -73,7 +75,13 @@ public class DefaultDistributedSetBuilder<E> implements DistributedSetBuilder<E>
     }
 
     @Override
+    public DistributedSetBuilder<E> withMeteringDisabled() {
+        metering = false;
+        return this;
+    }
+
+    @Override
     public DistributedSet<E> build() {
-        return new DefaultDistributedSet<E>(name, mapBuilder.build());
+        return new DefaultDistributedSet<E>(name, metering, mapBuilder.build());
     }
 }

+package org.onosproject.store.consistent.impl;
+
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import com.codahale.metrics.Timer;
+import com.google.common.collect.Maps;
+import org.onlab.metrics.MetricsComponent;
+import org.onlab.metrics.MetricsFeature;
+import org.onlab.metrics.MetricsService;
+import org.onlab.osgi.DefaultServiceDirectory;
+
+import java.util.Map;
+import java.util.concurrent.TimeUnit;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Agent that implements usage and performance monitoring via the metrics service.
+ */
+public class MeteringAgent {
+
+    private MetricsService metricsService;
+    private MetricsComponent metricsComponent;
+    private MetricsFeature metricsFeature;
+    private final Map<String, Timer> perObjOpTimers = Maps.newConcurrentMap();
+    private final Map<String, Timer> perOpTimers = Maps.newConcurrentMap();
+    private Timer perPrimitiveTimer;
+    private Timer perObjTimer;
+    private MetricsFeature wildcard;
+    private final boolean activated;
+    private Context nullTimer;
+
+    /**
+     * Constructs a new MeteringAgent for a given distributed primitive.
+     * Instantiates the metrics service
+     * Initializes all the general metrics for that object
+     *
+     * @param primitiveName Type of primitive to be metered
+     * @param objName Global name of the primitive
+     * @param activated
+     */
+    public MeteringAgent(String primitiveName, String objName, boolean activated) {
+        checkNotNull(objName, "Object name cannot be null");
+        this.activated = activated;
+        nullTimer = new Context(null, "");
+        if (this.activated) {
+            this.metricsService = DefaultServiceDirectory.getService(MetricsService.class);
+            this.metricsComponent = metricsService.registerComponent(primitiveName);
+            this.metricsFeature = metricsComponent.registerFeature(objName);
+            this.wildcard = metricsComponent.registerFeature("*");
+            this.perObjTimer = metricsService.createTimer(metricsComponent, metricsFeature, "*");
+            this.perPrimitiveTimer = metricsService.createTimer(metricsComponent, wildcard, "*");
+        }
+    }
+
+    /**
+     * Initializes a specific timer for a given operation.
+     *
+     * @param op Specific operation being metered
+     */
+    public Context startTimer(String op) {
+        if (!activated) {
+            return nullTimer;
+        }
+        // Check if timer exists, if it doesn't creates it
+        final Timer currTimer = perObjOpTimers.computeIfAbsent(op, timer ->
+                metricsService.createTimer(metricsComponent, metricsFeature, op));
+        perOpTimers.computeIfAbsent(op, timer -> metricsService.createTimer(metricsComponent, wildcard, op));
+        // Starts timer
+        return new Context(currTimer.time(), op);
+    }
+
+    /**
+     * Timer.Context with a specific operation.
+     */
+    public class Context {
+        private final Timer.Context context;
+        private final String operation;
+
+        /**
+         * Constructs Context.
+         *
+         * @param context
+         * @param operation
+         */
+        public Context(Timer.Context context, String operation) {
+            this.context = context;
+            this.operation = operation;
+        }
+
+        /**
+         * Stops timer given a specific context and updates all related metrics.
+         */
+        public void stop() {
+            if (!activated) {
+                return;
+            }
+            //Stop and updates timer with specific measurements per map, per operation
+            final long time = context.stop();
+            //updates timer with aggregated measurements per map
+            perOpTimers.get(operation).update(time, TimeUnit.NANOSECONDS);
+            //updates timer with aggregated measurements per map
+            perObjTimer.update(time, TimeUnit.NANOSECONDS);
+            //updates timer with aggregated measurements per all Consistent Maps
+            perPrimitiveTimer.update(time, TimeUnit.NANOSECONDS);
+        }
+    }
+
+}