diff --git a/core/src/main/java/io/atomix/core/counter/impl/AtomicCounterProxyBuilder.java b/core/src/main/java/io/atomix/core/counter/impl/AtomicCounterProxyBuilder.java
index b853ccb378..b00456ed4b 100644
--- a/core/src/main/java/io/atomix/core/counter/impl/AtomicCounterProxyBuilder.java
+++ b/core/src/main/java/io/atomix/core/counter/impl/AtomicCounterProxyBuilder.java
@@ -34,7 +34,7 @@ public AtomicCounterProxyBuilder(String name, AtomicCounterConfig config, Primit
   @Override
   @SuppressWarnings("unchecked")
   public CompletableFuture<AtomicCounter> buildAsync() {
-    PrimitiveProxy proxy = protocol.newProxy(
+    PrimitiveProxy proxy = protocol().newProxy(
         name(),
         primitiveType(),
         managementService.getPartitionService());
diff --git a/core/src/main/java/io/atomix/core/election/impl/LeaderElectionProxyBuilder.java b/core/src/main/java/io/atomix/core/election/impl/LeaderElectionProxyBuilder.java
index f0437544f7..4829e3a9d3 100644
--- a/core/src/main/java/io/atomix/core/election/impl/LeaderElectionProxyBuilder.java
+++ b/core/src/main/java/io/atomix/core/election/impl/LeaderElectionProxyBuilder.java
@@ -35,16 +35,16 @@ public LeaderElectionProxyBuilder(String name, LeaderElectionConfig config, Prim
   @Override
   @SuppressWarnings("unchecked")
   public CompletableFuture<LeaderElection<T>> buildAsync() {
-    PrimitiveProxy proxy = protocol.newProxy(
+    PrimitiveProxy proxy = protocol().newProxy(
         name(),
         primitiveType(),
         managementService.getPartitionService());
     return new LeaderElectionProxy(proxy, managementService.getPrimitiveRegistry())
         .connect()
-        .thenApply(elector -> {
+        .thenApply(election -> {
           Serializer serializer = serializer();
           return new TranscodingAsyncLeaderElection<T, byte[]>(
-              elector,
+              election,
               key -> serializer.encode(key),
               bytes -> serializer.decode(bytes))
               .sync();
diff --git a/core/src/main/java/io/atomix/core/election/impl/LeaderElectorProxyBuilder.java b/core/src/main/java/io/atomix/core/election/impl/LeaderElectorProxyBuilder.java
index baa54bff0d..a2a12269f3 100644
--- a/core/src/main/java/io/atomix/core/election/impl/LeaderElectorProxyBuilder.java
+++ b/core/src/main/java/io/atomix/core/election/impl/LeaderElectorProxyBuilder.java
@@ -35,7 +35,7 @@ public LeaderElectorProxyBuilder(String name, LeaderElectorConfig config, Primit
   @Override
   @SuppressWarnings("unchecked")
   public CompletableFuture<LeaderElector<T>> buildAsync() {
-    PrimitiveProxy proxy = protocol.newProxy(
+    PrimitiveProxy proxy = protocol().newProxy(
         name(),
         primitiveType(),
         managementService.getPartitionService());
diff --git a/core/src/main/java/io/atomix/core/generator/impl/DelegatingAtomicIdGeneratorBuilder.java b/core/src/main/java/io/atomix/core/generator/impl/DelegatingAtomicIdGeneratorBuilder.java
index 45661ebb48..069a022b51 100644
--- a/core/src/main/java/io/atomix/core/generator/impl/DelegatingAtomicIdGeneratorBuilder.java
+++ b/core/src/main/java/io/atomix/core/generator/impl/DelegatingAtomicIdGeneratorBuilder.java
@@ -35,7 +35,7 @@ public DelegatingAtomicIdGeneratorBuilder(String name, AtomicIdGeneratorConfig c
   @Override
   @SuppressWarnings("unchecked")
   public CompletableFuture<AtomicIdGenerator> buildAsync() {
-    PrimitiveProxy proxy = protocol.newProxy(
+    PrimitiveProxy proxy = protocol().newProxy(
         name(),
         primitiveType(),
         managementService.getPartitionService());
diff --git a/core/src/main/java/io/atomix/core/lock/impl/DistributedLockProxyBuilder.java b/core/src/main/java/io/atomix/core/lock/impl/DistributedLockProxyBuilder.java
index 61066637ed..5e1681295d 100644
--- a/core/src/main/java/io/atomix/core/lock/impl/DistributedLockProxyBuilder.java
+++ b/core/src/main/java/io/atomix/core/lock/impl/DistributedLockProxyBuilder.java
@@ -35,7 +35,7 @@ public DistributedLockProxyBuilder(String name, DistributedLockConfig config, Pr
   @Override
   @SuppressWarnings("unchecked")
   public CompletableFuture<DistributedLock> buildAsync() {
-    PrimitiveProxy proxy = protocol.newProxy(
+    PrimitiveProxy proxy = protocol().newProxy(
         name(),
         primitiveType(),
         managementService.getPartitionService());
diff --git a/core/src/main/java/io/atomix/core/map/impl/AtomicCounterMapProxyBuilder.java b/core/src/main/java/io/atomix/core/map/impl/AtomicCounterMapProxyBuilder.java
index efab43155d..da463cb88a 100644
--- a/core/src/main/java/io/atomix/core/map/impl/AtomicCounterMapProxyBuilder.java
+++ b/core/src/main/java/io/atomix/core/map/impl/AtomicCounterMapProxyBuilder.java
@@ -36,16 +36,16 @@ public AtomicCounterMapProxyBuilder(String name, AtomicCounterMapConfig config,
   @Override
   @SuppressWarnings("unchecked")
   public CompletableFuture<AtomicCounterMap<K>> buildAsync() {
-    PrimitiveProxy proxy = protocol.newProxy(
+    PrimitiveProxy proxy = protocol().newProxy(
         name(),
         primitiveType(),
         managementService.getPartitionService());
     return new AtomicCounterMapProxy(proxy, managementService.getPrimitiveRegistry())
         .connect()
-        .thenApply(multimap -> {
+        .thenApply(map -> {
           Serializer serializer = serializer();
           return new TranscodingAsyncAtomicCounterMap<K, String>(
-              multimap,
+              map,
               key -> BaseEncoding.base16().encode(serializer.encode(key)),
               string -> serializer.decode(BaseEncoding.base16().decode(string)))
               .sync();
diff --git a/core/src/main/java/io/atomix/core/map/impl/ConsistentMapProxyBuilder.java b/core/src/main/java/io/atomix/core/map/impl/ConsistentMapProxyBuilder.java
index e5c90b3180..819dfc02bd 100644
--- a/core/src/main/java/io/atomix/core/map/impl/ConsistentMapProxyBuilder.java
+++ b/core/src/main/java/io/atomix/core/map/impl/ConsistentMapProxyBuilder.java
@@ -40,7 +40,7 @@ public ConsistentMapProxyBuilder(String name, ConsistentMapConfig config, Primit
   @Override
   @SuppressWarnings("unchecked")
   public CompletableFuture<ConsistentMap<K, V>> buildAsync() {
-    PrimitiveProxy proxy = protocol.newProxy(
+    PrimitiveProxy proxy = protocol().newProxy(
         name(),
         primitiveType(),
         managementService.getPartitionService());
diff --git a/core/src/main/java/io/atomix/core/map/impl/ConsistentTreeMapProxyBuilder.java b/core/src/main/java/io/atomix/core/map/impl/ConsistentTreeMapProxyBuilder.java
index 36907b12d5..27f624c23a 100644
--- a/core/src/main/java/io/atomix/core/map/impl/ConsistentTreeMapProxyBuilder.java
+++ b/core/src/main/java/io/atomix/core/map/impl/ConsistentTreeMapProxyBuilder.java
@@ -38,7 +38,7 @@ public ConsistentTreeMapProxyBuilder(String name, ConsistentTreeMapConfig config
   @Override
   @SuppressWarnings("unchecked")
   public CompletableFuture<ConsistentTreeMap<V>> buildAsync() {
-    PrimitiveProxy proxy = protocol.newProxy(
+    PrimitiveProxy proxy = protocol().newProxy(
         name(),
         primitiveType(),
         managementService.getPartitionService());
diff --git a/core/src/main/java/io/atomix/core/multimap/impl/ConsistentMultimapProxyBuilder.java b/core/src/main/java/io/atomix/core/multimap/impl/ConsistentMultimapProxyBuilder.java
index 731605e110..df4062e71e 100644
--- a/core/src/main/java/io/atomix/core/multimap/impl/ConsistentMultimapProxyBuilder.java
+++ b/core/src/main/java/io/atomix/core/multimap/impl/ConsistentMultimapProxyBuilder.java
@@ -38,7 +38,7 @@ public ConsistentMultimapProxyBuilder(String name, ConsistentMultimapConfig conf
   @Override
   @SuppressWarnings("unchecked")
   public CompletableFuture<ConsistentMultimap<K, V>> buildAsync() {
-    PrimitiveProxy proxy = protocol.newProxy(
+    PrimitiveProxy proxy = protocol().newProxy(
         name(),
         primitiveType(),
         managementService.getPartitionService());
diff --git a/core/src/main/java/io/atomix/core/queue/impl/WorkQueueProxyBuilder.java b/core/src/main/java/io/atomix/core/queue/impl/WorkQueueProxyBuilder.java
index 7ef0962914..eb135ef97e 100644
--- a/core/src/main/java/io/atomix/core/queue/impl/WorkQueueProxyBuilder.java
+++ b/core/src/main/java/io/atomix/core/queue/impl/WorkQueueProxyBuilder.java
@@ -35,7 +35,7 @@ public WorkQueueProxyBuilder(String name, WorkQueueConfig config, PrimitiveManag
   @Override
   @SuppressWarnings("unchecked")
   public CompletableFuture<WorkQueue<E>> buildAsync() {
-    PrimitiveProxy proxy = protocol.newProxy(
+    PrimitiveProxy proxy = protocol().newProxy(
         name(),
         primitiveType(),
         managementService.getPartitionService());
diff --git a/core/src/main/java/io/atomix/core/set/impl/DelegatingDistributedSetBuilder.java b/core/src/main/java/io/atomix/core/set/impl/DelegatingDistributedSetBuilder.java
index c440ef21c5..bcd501e359 100644
--- a/core/src/main/java/io/atomix/core/set/impl/DelegatingDistributedSetBuilder.java
+++ b/core/src/main/java/io/atomix/core/set/impl/DelegatingDistributedSetBuilder.java
@@ -43,7 +43,7 @@ public DelegatingDistributedSetBuilder(String name, DistributedSetConfig config,
   @Override
   @SuppressWarnings("unchecked")
   public CompletableFuture<DistributedSet<E>> buildAsync() {
-    PrimitiveProxy proxy = protocol.newProxy(
+    PrimitiveProxy proxy = protocol().newProxy(
         name(),
         primitiveType(),
         managementService.getPartitionService());
diff --git a/core/src/main/java/io/atomix/core/tree/impl/DocumentTreeProxyBuilder.java b/core/src/main/java/io/atomix/core/tree/impl/DocumentTreeProxyBuilder.java
index bbedc4dd2c..f337a27430 100644
--- a/core/src/main/java/io/atomix/core/tree/impl/DocumentTreeProxyBuilder.java
+++ b/core/src/main/java/io/atomix/core/tree/impl/DocumentTreeProxyBuilder.java
@@ -38,7 +38,7 @@ public DocumentTreeProxyBuilder(String name, DocumentTreeConfig config, Primitiv
   @Override
   @SuppressWarnings("unchecked")
   public CompletableFuture<DocumentTree<V>> buildAsync() {
-    PrimitiveProxy proxy = protocol.newProxy(
+    PrimitiveProxy proxy = protocol().newProxy(
         name(),
         primitiveType(),
         managementService.getPartitionService());
diff --git a/core/src/main/java/io/atomix/core/value/impl/AtomicValueProxyBuilder.java b/core/src/main/java/io/atomix/core/value/impl/AtomicValueProxyBuilder.java
index f18fffa3b3..e7bbae8ad2 100644
--- a/core/src/main/java/io/atomix/core/value/impl/AtomicValueProxyBuilder.java
+++ b/core/src/main/java/io/atomix/core/value/impl/AtomicValueProxyBuilder.java
@@ -37,7 +37,7 @@ public AtomicValueProxyBuilder(String name, AtomicValueConfig config, PrimitiveM
   @Override
   @SuppressWarnings("unchecked")
   public CompletableFuture<AtomicValue<V>> buildAsync() {
-    PrimitiveProxy proxy = protocol.newProxy(
+    PrimitiveProxy proxy = protocol().newProxy(
         name(),
         primitiveType(),
         managementService.getPartitionService());
diff --git a/primitive/src/main/java/io/atomix/primitive/DistributedPrimitiveBuilder.java b/primitive/src/main/java/io/atomix/primitive/DistributedPrimitiveBuilder.java
index be13ad5c38..8149c2e1c6 100644
--- a/primitive/src/main/java/io/atomix/primitive/DistributedPrimitiveBuilder.java
+++ b/primitive/src/main/java/io/atomix/primitive/DistributedPrimitiveBuilder.java
@@ -35,7 +35,7 @@
  * @param <P> primitive type
  */
 public abstract class DistributedPrimitiveBuilder<B extends DistributedPrimitiveBuilder<B, C, P>, C extends PrimitiveConfig, P extends DistributedPrimitive> implements Builder<P> {
-  private final PrimitiveType type;
+  protected final PrimitiveType type;
   protected final String name;
   protected final C config;
   protected Serializer serializer;
diff --git a/protocols/primary-backup/src/main/java/io/atomix/protocols/backup/MultiPrimaryProtocol.java b/protocols/primary-backup/src/main/java/io/atomix/protocols/backup/MultiPrimaryProtocol.java
index ea9d03cc44..6f84089631 100644
--- a/protocols/primary-backup/src/main/java/io/atomix/protocols/backup/MultiPrimaryProtocol.java
+++ b/protocols/primary-backup/src/main/java/io/atomix/protocols/backup/MultiPrimaryProtocol.java
@@ -97,7 +97,7 @@ public PrimitiveProxy newProxy(String primitiveName, PrimitiveType primitiveType
             .withConsistency(config.getConsistency())
             .withReplication(config.getReplication())
             .withRecovery(config.getRecovery())
-            .withNumBackups(config.getNumBackups())
+            .withNumBackups(config.getBackups())
             .withMaxRetries(config.getMaxRetries())
             .withRetryDelay(config.getRetryDelay())
             .withExecutor(config.getExecutor())
@@ -173,7 +173,7 @@ public Builder withRecovery(Recovery recovery) {
      * @return the protocol builder
      */
     public Builder withBackups(int numBackups) {
-      config.setNumBackups(numBackups);
+      config.setBackups(numBackups);
       return this;
     }
 
diff --git a/protocols/primary-backup/src/main/java/io/atomix/protocols/backup/MultiPrimaryProtocolConfig.java b/protocols/primary-backup/src/main/java/io/atomix/protocols/backup/MultiPrimaryProtocolConfig.java
index 1cb55af532..8ed30c94ff 100644
--- a/protocols/primary-backup/src/main/java/io/atomix/protocols/backup/MultiPrimaryProtocolConfig.java
+++ b/protocols/primary-backup/src/main/java/io/atomix/protocols/backup/MultiPrimaryProtocolConfig.java
@@ -33,7 +33,7 @@ public class MultiPrimaryProtocolConfig extends PrimitiveProtocolConfig<MultiPri
   private Consistency consistency = Consistency.SEQUENTIAL;
   private Replication replication = Replication.ASYNCHRONOUS;
   private Recovery recovery = Recovery.RECOVER;
-  private int numBackups = 1;
+  private int backups = 1;
   private int maxRetries = 0;
   private Duration retryDelay = Duration.ofMillis(100);
   private Executor executor;
@@ -128,8 +128,8 @@ public MultiPrimaryProtocolConfig setRecovery(Recovery recovery) {
    *
    * @return the number of backups
    */
-  public int getNumBackups() {
-    return numBackups;
+  public int getBackups() {
+    return backups;
   }
 
   /**
@@ -138,8 +138,8 @@ public int getNumBackups() {
    * @param numBackups the number of backups
    * @return the protocol configuration
    */
-  public MultiPrimaryProtocolConfig setNumBackups(int numBackups) {
-    this.numBackups = numBackups;
+  public MultiPrimaryProtocolConfig setBackups(int numBackups) {
+    this.backups = numBackups;
     return this;
   }
 
diff --git a/rest/src/test/java/io/atomix/rest/impl/VertxRestServiceTest.java b/rest/src/test/java/io/atomix/rest/impl/VertxRestServiceTest.java
index 2be7d9f4de..3b9cb1499a 100644
--- a/rest/src/test/java/io/atomix/rest/impl/VertxRestServiceTest.java
+++ b/rest/src/test/java/io/atomix/rest/impl/VertxRestServiceTest.java
@@ -86,7 +86,7 @@ public void testCluster() throws Exception {
         .statusCode(200)
         .assertThat()
         .body("id", equalTo("1"))
-        .body("type", equalTo("DATA"))
+        .body("type", equalTo("EPHEMERAL"))
         .body("host", equalTo(instances.get(0).membershipService().getLocalMember().address().host()))
         .body("port", equalTo(instances.get(0).membershipService().getLocalMember().address().port()))
         .body("status", equalTo("ACTIVE"));
@@ -180,10 +180,14 @@ public void testMessages() throws Exception {
 
   @Test
   public void testMap() throws Exception {
-    JsonNode json = JsonNodeFactory.withExactBigDecimals(true).objectNode()
+    JsonNodeFactory jsonFactory = JsonNodeFactory.withExactBigDecimals(true);
+    JsonNode json = jsonFactory.objectNode()
         .put("type", "consistent-map")
         .put("cache-enabled", true)
-        .put("null-values", false);
+        .put("null-values", false)
+        .set("protocol", jsonFactory.objectNode()
+            .put("type", "multi-primary")
+            .put("backups", 2));
 
     given()
         .spec(specs.get(0))