Merge pull request #18525 from vespa-engine/jonmv/reapply-di-session-cache

Session cache with injected config and network [run-systemtest]

45 files changed, 706 insertions, 283 deletions

diff --git a/config-model/src/main/java/com/yahoo/vespa/model/container/ApplicationContainer.java b/config-model/src/main/java/com/yahoo/vespa/model/container/ApplicationContainer.java
index 02a0f606603..792fa3f1884 100644
--- a/config-model/src/main/java/com/yahoo/vespa/model/container/ApplicationContainer.java
+++ b/config-model/src/main/java/com/yahoo/vespa/model/container/ApplicationContainer.java
@@ -9,6 +9,7 @@ import com.yahoo.config.model.producer.AbstractConfigProducer;
 import com.yahoo.config.provision.ClusterSpec;
 import com.yahoo.config.provision.NodeResources;
 import com.yahoo.search.config.QrStartConfig;
+import com.yahoo.vespa.model.container.component.SimpleComponent;
 
 /**
  * A container that is typically used by container clusters set up from the user application.
@@ -30,6 +31,10 @@ public final class ApplicationContainer extends Container implements
     public ApplicationContainer(AbstractConfigProducer<?> parent, String name, boolean retired, int index, DeployState deployState) {
         super(parent, name, retired, index, deployState);
         this.isHostedVespa = deployState.isHosted();
+
+        addComponent(new SimpleComponent("com.yahoo.container.jdisc.messagebus.NetworkMultiplexerHolder"));
+        addComponent(new SimpleComponent("com.yahoo.container.jdisc.messagebus.NetworkMultiplexerProvider"));
+        addComponent(new SimpleComponent("com.yahoo.container.jdisc.messagebus.SessionCache"));
     }
 
     @Override
diff --git a/config-model/src/main/java/com/yahoo/vespa/model/container/ApplicationContainerCluster.java b/config-model/src/main/java/com/yahoo/vespa/model/container/ApplicationContainerCluster.java
index d0bcfde3c0c..57169391cbb 100644
--- a/config-model/src/main/java/com/yahoo/vespa/model/container/ApplicationContainerCluster.java
+++ b/config-model/src/main/java/com/yahoo/vespa/model/container/ApplicationContainerCluster.java
@@ -107,6 +107,7 @@ public final class ApplicationContainerCluster extends ContainerCluster<Applicat
         addSimpleComponent("com.yahoo.container.jdisc.AthenzIdentityProviderProvider");
         addSimpleComponent("com.yahoo.container.jdisc.SystemInfoProvider");
         addSimpleComponent(com.yahoo.container.core.documentapi.DocumentAccessProvider.class.getName());
+
         addMetricsHandlers();
         addTestrunnerComponentsIfTester(deployState);
     }
diff --git a/container-disc/src/main/java/com/yahoo/container/jdisc/ConfiguredApplication.java b/container-disc/src/main/java/com/yahoo/container/jdisc/ConfiguredApplication.java
index 0e4c4446778..9fe3728dc2c 100644
--- a/container-disc/src/main/java/com/yahoo/container/jdisc/ConfiguredApplication.java
+++ b/container-disc/src/main/java/com/yahoo/container/jdisc/ConfiguredApplication.java
@@ -18,7 +18,6 @@ import com.yahoo.container.di.config.Subscriber;
 import com.yahoo.container.di.config.SubscriberFactory;
 import com.yahoo.container.http.filter.FilterChainRepository;
 import com.yahoo.container.jdisc.component.Deconstructor;
-import com.yahoo.container.jdisc.messagebus.SessionCache;
 import com.yahoo.container.jdisc.metric.DisableGuiceMetric;
 import com.yahoo.jdisc.Metric;
 import com.yahoo.jdisc.application.Application;
@@ -77,7 +76,6 @@ public final class ConfiguredApplication implements Application {
     // to config to make sure that container will be registered in slobrok (by {@link com.yahoo.jrt.slobrok.api.Register})
     // if slobrok config changes (typically slobroks moving to other nodes)
     private final Optional<SlobrokConfigSubscriber> slobrokConfigSubscriber;
-    private final SessionCache sessionCache;
 
     //TODO: FilterChainRepository should instead always be set up in the model.
     private final FilterChainRepository defaultFilterChainRepository =
@@ -127,7 +125,6 @@ public final class ConfiguredApplication implements Application {
         this.slobrokConfigSubscriber = (subscriberFactory instanceof CloudSubscriberFactory)
                 ? Optional.of(new SlobrokConfigSubscriber(configId))
                 : Optional.empty();
-        this.sessionCache = new SessionCache(configId);
         this.restrictedOsgiFramework = new DisableOsgiFramework(new RestrictedBundleContext(osgiFramework.bundleContext()));
     }
 
@@ -148,8 +145,8 @@ public final class ConfiguredApplication implements Application {
     }
 
     /**
-     * The container has no RPC methods, but we still need an RPC sever
-     * to register in Slobrok to enable orchestration
+     * The container has no RPC methods, but we still need an RPC server
+     * to register in Slobrok to enable orchestration.
      */
     private Register registerInSlobrok(QrConfig qrConfig) {
         if ( ! qrConfig.rpc().enabled()) return null;
@@ -349,7 +346,6 @@ public final class ConfiguredApplication implements Application {
                 bind(OsgiFramework.class).toInstance(restrictedOsgiFramework);
                 bind(com.yahoo.jdisc.Timer.class).toInstance(timerSingleton);
                 bind(FilterChainRepository.class).toInstance(defaultFilterChainRepository);
-                bind(SessionCache.class).toInstance(sessionCache); // Needed by e.g. FeedHandler
             }
         });
     }
diff --git a/container-messagebus/src/main/java/com/yahoo/container/jdisc/messagebus/NetworkMultiplexerHolder.java b/container-messagebus/src/main/java/com/yahoo/container/jdisc/messagebus/NetworkMultiplexerHolder.java
new file mode 100644
index 00000000000..9020bfaffe3
--- /dev/null
+++ b/container-messagebus/src/main/java/com/yahoo/container/jdisc/messagebus/NetworkMultiplexerHolder.java
@@ -0,0 +1,45 @@
+// Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.container.jdisc.messagebus;
+
+import com.yahoo.component.AbstractComponent;
+import com.yahoo.messagebus.network.Network;
+import com.yahoo.messagebus.network.NetworkMultiplexer;
+import com.yahoo.messagebus.network.rpc.RPCNetwork;
+import com.yahoo.messagebus.network.rpc.RPCNetworkParams;
+import com.yahoo.messagebus.shared.NullNetwork;
+
+/**
+ * Holds a reference to a singleton {@link NetworkMultiplexer}.
+ *
+ * @author jonmv
+ */
+public class NetworkMultiplexerHolder extends AbstractComponent {
+
+    private final Object monitor = new Object();
+    private boolean destroyed = false;
+    private NetworkMultiplexer net;
+
+    /** Get the singleton RPCNetworkAdapter, creating it if this hasn't yet been done. */
+    public NetworkMultiplexer get(RPCNetworkParams params) {
+        synchronized (monitor) {
+            if (destroyed)
+                throw new IllegalStateException("Component already destroyed");
+
+            return net = net != null ? net : NetworkMultiplexer.shared(newNetwork(params));
+        }
+    }
+
+    private Network newNetwork(RPCNetworkParams params) {
+        return params.getSlobroksConfig().slobrok().isEmpty() ? new NullNetwork() : new RPCNetwork(params);
+    }
+
+    @Override
+    public void deconstruct() {
+        synchronized (monitor) {
+            net.destroy();
+            net = null;
+            destroyed = true;
+        }
+    }
+
+}
diff --git a/container-messagebus/src/main/java/com/yahoo/container/jdisc/messagebus/NetworkMultiplexerProvider.java b/container-messagebus/src/main/java/com/yahoo/container/jdisc/messagebus/NetworkMultiplexerProvider.java
new file mode 100644
index 00000000000..650ac92e779
--- /dev/null
+++ b/container-messagebus/src/main/java/com/yahoo/container/jdisc/messagebus/NetworkMultiplexerProvider.java
@@ -0,0 +1,44 @@
+// Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.container.jdisc.messagebus;
+
+import com.google.inject.Inject;
+import com.yahoo.cloud.config.SlobroksConfig;
+import com.yahoo.container.jdisc.ContainerMbusConfig;
+import com.yahoo.messagebus.network.Identity;
+import com.yahoo.messagebus.network.NetworkMultiplexer;
+import com.yahoo.messagebus.network.rpc.RPCNetworkParams;
+
+/**
+ * Injectable component which provides an {@link NetworkMultiplexer}, creating one if needed,
+ * i.e., the first time this is created in a container--subsequent creations of this will reuse
+ * the underlying network that was created initially. This breaks the DI pattern, but must be done
+ * because the network is a unique resource which cannot exist in several versions simultaneously.
+ *
+ * @author jonmv
+ */
+public class NetworkMultiplexerProvider {
+
+    private final NetworkMultiplexer net;
+
+    @Inject
+    public NetworkMultiplexerProvider(NetworkMultiplexerHolder net, ContainerMbusConfig mbusConfig, SlobroksConfig slobroksConfig) {
+        this(net, mbusConfig, slobroksConfig, System.getProperty("config.id")); //:
+    }
+
+    public NetworkMultiplexerProvider(NetworkMultiplexerHolder net, ContainerMbusConfig mbusConfig, SlobroksConfig slobroksConfig, String identity) {
+        this.net = net.get(asParameters(mbusConfig, slobroksConfig, identity));
+    }
+
+    public static RPCNetworkParams asParameters(ContainerMbusConfig mbusConfig, SlobroksConfig slobroksConfig, String identity) {
+        return new RPCNetworkParams().setSlobroksConfig(slobroksConfig)
+                                     .setIdentity(new Identity(identity))
+                                     .setListenPort(mbusConfig.port())
+                                     .setNumTargetsPerSpec(mbusConfig.numconnectionspertarget())
+                                     .setNumNetworkThreads(mbusConfig.numthreads())
+                                     .setTransportEventsBeforeWakeup(mbusConfig.transport_events_before_wakeup())
+                                     .setOptimization(RPCNetworkParams.Optimization.valueOf(mbusConfig.optimize_for().name()));
+    }
+
+    public NetworkMultiplexer net() { return net; }
+
+}
diff --git a/container-messagebus/src/main/java/com/yahoo/container/jdisc/messagebus/SessionCache.java b/container-messagebus/src/main/java/com/yahoo/container/jdisc/messagebus/SessionCache.java
index d65b2f7cc12..3e3902b35aa 100644
--- a/container-messagebus/src/main/java/com/yahoo/container/jdisc/messagebus/SessionCache.java
+++ b/container-messagebus/src/main/java/com/yahoo/container/jdisc/messagebus/SessionCache.java
@@ -1,34 +1,40 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.container.jdisc.messagebus;
 
+import com.google.inject.Inject;
+import com.yahoo.cloud.config.SlobroksConfig;
 import com.yahoo.component.AbstractComponent;
-import com.yahoo.config.subscription.ConfigGetter;
 import com.yahoo.container.jdisc.ContainerMbusConfig;
 import com.yahoo.document.DocumentTypeManager;
 import com.yahoo.document.DocumentUtil;
+import com.yahoo.document.config.DocumentmanagerConfig;
 import com.yahoo.documentapi.messagebus.loadtypes.LoadTypeSet;
 import com.yahoo.documentapi.messagebus.protocol.DocumentProtocol;
+import com.yahoo.documentapi.messagebus.protocol.DocumentProtocolPoliciesConfig;
 import com.yahoo.jdisc.ReferencedResource;
 import com.yahoo.jdisc.References;
 import com.yahoo.jdisc.ResourceReference;
 import com.yahoo.jdisc.SharedResource;
-import java.util.logging.Level;
 import com.yahoo.messagebus.ConfigAgent;
 import com.yahoo.messagebus.DynamicThrottlePolicy;
 import com.yahoo.messagebus.IntermediateSessionParams;
+import com.yahoo.messagebus.MessageBus;
 import com.yahoo.messagebus.MessageBusParams;
+import com.yahoo.messagebus.MessagebusConfig;
 import com.yahoo.messagebus.Protocol;
 import com.yahoo.messagebus.SourceSessionParams;
 import com.yahoo.messagebus.StaticThrottlePolicy;
 import com.yahoo.messagebus.ThrottlePolicy;
-import com.yahoo.messagebus.network.Identity;
-import com.yahoo.messagebus.network.rpc.RPCNetworkParams;
+import com.yahoo.messagebus.network.NetworkMultiplexer;
 import com.yahoo.messagebus.shared.SharedIntermediateSession;
 import com.yahoo.messagebus.shared.SharedMessageBus;
 import com.yahoo.messagebus.shared.SharedSourceSession;
+import com.yahoo.vespa.config.content.DistributionConfig;
+import com.yahoo.vespa.config.content.LoadTypeConfig;
 
 import java.util.HashMap;
 import java.util.Map;
+import java.util.logging.Level;
 import java.util.logging.Logger;
 
 /**
@@ -37,24 +43,19 @@ import java.util.logging.Logger;
  * @author Steinar Knutsen
  * @author Einar Rosenvinge
  */
-// TODO jonmv: Remove this? Only used sensibly by FeedHandlerV3, where only timeout varies.
+// TODO jonmv: Remove this: only used with more than one entry by FeedHandlerV3, where only timeout varies.
+// rant: This whole construct is because DI at one point didn't exist, so getting hold of a shared resource
+//       or session was hard(?), and one resorted to routing through the Container, using URIs, to the correct
+//       MbusClient, with or without throttling. This introduced the problem of ownership during shutdown,
+//       which was solved with manual reference counting. This is all much better solved with DI, which (now)
+//       owns everything, and does component shutdown in reverse construction order, which is always right.
+//       So for the sake of everyone's mental health, this should all just be removed now! I suspect this is
+//       even the case for Request; we can track in handlers, and warn when requests have been misplaced.
 public final class SessionCache extends AbstractComponent {
 
     private static final Logger log = Logger.getLogger(SessionCache.class.getName());
 
-    //config
-    private final String messagebusConfigId;
-    private final String slobrokConfigId;
-    private final String identity;
-    private final String containerMbusConfigId;
-    private final String documentManagerConfigId;
-    private final String loadTypeConfigId;
-    private final DocumentTypeManager documentTypeManager;
-
-    // initialized in start()
-    private ConfigAgent configAgent;
-    private SharedMessageBus messageBus;
-
+    private final SharedMessageBus messageBus;
     private final Object intermediateLock = new Object();
     private final Map<String, SharedIntermediateSession> intermediates = new HashMap<>();
     private final IntermediateSessionCreator intermediatesCreator = new IntermediateSessionCreator();
@@ -63,50 +64,43 @@ public final class SessionCache extends AbstractComponent {
     private final Map<SourceSessionKey, SharedSourceSession> sources = new HashMap<>();
     private final SourceSessionCreator sourcesCreator = new SourceSessionCreator();
 
-    public SessionCache(String messagebusConfigId, String slobrokConfigId, String identity,
-                        String containerMbusConfigId, String documentManagerConfigId,
-                        String loadTypeConfigId,
-                        DocumentTypeManager documentTypeManager) {
-        this.messagebusConfigId = messagebusConfigId;
-        this.slobrokConfigId = slobrokConfigId;
-        this.identity = identity;
-        this.containerMbusConfigId = containerMbusConfigId;
-        this.documentManagerConfigId = documentManagerConfigId;
-        this.loadTypeConfigId = loadTypeConfigId;
-        this.documentTypeManager = documentTypeManager;
-    }
+    @Inject
+    public SessionCache(NetworkMultiplexerProvider nets, ContainerMbusConfig containerMbusConfig,
+                        DocumentmanagerConfig documentmanagerConfig,
+                        LoadTypeConfig loadTypeConfig, MessagebusConfig messagebusConfig,
+                        DocumentProtocolPoliciesConfig policiesConfig,
+                        DistributionConfig distributionConfig) {
+        this(nets.net(), containerMbusConfig, documentmanagerConfig,
+             loadTypeConfig, messagebusConfig, policiesConfig, distributionConfig);
 
-    public SessionCache(final String identity) {
-        this(identity, identity, identity, identity, identity, identity, new DocumentTypeManager());
     }
 
-    public void deconstruct() {
-        if (configAgent != null) {
-            configAgent.shutdown();
-        }
+    public SessionCache(NetworkMultiplexer net, ContainerMbusConfig containerMbusConfig,
+                        DocumentmanagerConfig documentmanagerConfig,
+                        LoadTypeConfig loadTypeConfig, MessagebusConfig messagebusConfig,
+                        DocumentProtocolPoliciesConfig policiesConfig,
+                        DistributionConfig distributionConfig) {
+        this(net,
+             containerMbusConfig,
+             messagebusConfig,
+             new DocumentProtocol(new DocumentTypeManager(documentmanagerConfig),
+                                  new LoadTypeSet(loadTypeConfig),
+                                  policiesConfig,
+                                  distributionConfig));
     }
 
-
-    private void start() {
-        ContainerMbusConfig mbusConfig = ConfigGetter.getConfig(ContainerMbusConfig.class, containerMbusConfigId);
-        if (documentManagerConfigId != null) {
-            documentTypeManager.configure(documentManagerConfigId);
-        }
-        LoadTypeSet loadTypeSet = new LoadTypeSet(loadTypeConfigId);
-        DocumentProtocol protocol = new DocumentProtocol(documentTypeManager, identity, loadTypeSet);
-        messageBus = createSharedMessageBus(mbusConfig, slobrokConfigId, identity, protocol);
-        // TODO: stop doing subscriptions to config when that is to be solved in slobrok as well
-        configAgent = new ConfigAgent(messagebusConfigId, messageBus.messageBus());
-        configAgent.subscribe();
+    public SessionCache(NetworkMultiplexer net, ContainerMbusConfig containerMbusConfig,
+                        MessagebusConfig messagebusConfig, Protocol protocol) {
+        this.messageBus = createSharedMessageBus(net, containerMbusConfig, messagebusConfig, protocol);
     }
 
-
-    private boolean isStarted() {
-        return messageBus != null;
+    public void deconstruct() {
+        messageBus.release();
     }
 
-    private static SharedMessageBus createSharedMessageBus(ContainerMbusConfig mbusConfig,
-                                                           String slobrokConfigId, String identity,
+    private static SharedMessageBus createSharedMessageBus(NetworkMultiplexer net,
+                                                           ContainerMbusConfig mbusConfig,
+                                                           MessagebusConfig messagebusConfig,
                                                            Protocol protocol) {
         MessageBusParams mbusParams = new MessageBusParams().addProtocol(protocol);
 
@@ -118,15 +112,9 @@ public final class SessionCache extends AbstractComponent {
         mbusParams.setMaxPendingCount(mbusConfig.maxpendingcount());
         mbusParams.setMaxPendingSize(maxPendingSize);
 
-        RPCNetworkParams netParams = new RPCNetworkParams()
-                .setSlobrokConfigId(slobrokConfigId)
-                .setIdentity(new Identity(identity))
-                .setListenPort(mbusConfig.port())
-                .setNumTargetsPerSpec(mbusConfig.numconnectionspertarget())
-                .setNumNetworkThreads(mbusConfig.numthreads())
-                .setTransportEventsBeforeWakeup(mbusConfig.transport_events_before_wakeup())
-                .setOptimization(RPCNetworkParams.Optimization.valueOf(mbusConfig.optimize_for().name()));
-        return SharedMessageBus.newInstance(mbusParams, netParams);
+        MessageBus bus = new MessageBus(net, mbusParams);
+        new ConfigAgent(messagebusConfig, bus); // Configure the wrapped MessageBus with a routing table.
+        return new SharedMessageBus(bus);
     }
 
     private static void logSystemInfo(ContainerMbusConfig containerMbusConfig, long maxPendingSize) {
@@ -144,20 +132,10 @@ public final class SessionCache extends AbstractComponent {
     }
 
     ReferencedResource<SharedIntermediateSession> retainIntermediate(final IntermediateSessionParams p) {
-        synchronized (this) {
-            if (!isStarted()) {
-                start();
-            }
-        }
         return intermediatesCreator.retain(intermediateLock, intermediates, p);
     }
 
     public ReferencedResource<SharedSourceSession> retainSource(final SourceSessionParams p) {
-        synchronized (this) {
-            if (!isStarted()) {
-                start();
-            }
-        }
         return sourcesCreator.retain(sourceLock, sources, p);
     }
 
diff --git a/container-messagebus/src/main/java/com/yahoo/messagebus/jdisc/MbusServer.java b/container-messagebus/src/main/java/com/yahoo/messagebus/jdisc/MbusServer.java
index e26e1e7e134..a2131f22dc4 100644
--- a/container-messagebus/src/main/java/com/yahoo/messagebus/jdisc/MbusServer.java
+++ b/container-messagebus/src/main/java/com/yahoo/messagebus/jdisc/MbusServer.java
@@ -50,6 +50,7 @@ public final class MbusServer extends AbstractResource implements ServerProvider
     public void close() {
         log.log(Level.FINE, "Closing message bus server.");
         running.set(false);
+        session.close();
     }
 
     @Override
diff --git a/container-messagebus/src/main/java/com/yahoo/messagebus/jdisc/test/ClientTestDriver.java b/container-messagebus/src/main/java/com/yahoo/messagebus/jdisc/test/ClientTestDriver.java
index 111805d61b0..ea0ed7eadc8 100644
--- a/container-messagebus/src/main/java/com/yahoo/messagebus/jdisc/test/ClientTestDriver.java
+++ b/container-messagebus/src/main/java/com/yahoo/messagebus/jdisc/test/ClientTestDriver.java
@@ -33,7 +33,7 @@ public class ClientTestDriver {
         this.server = server;
 
         MessageBusParams mbusParams = new MessageBusParams().addProtocol(protocol);
-        RPCNetworkParams netParams = new RPCNetworkParams().setSlobrokConfigId(server.slobrokId());
+        RPCNetworkParams netParams = new RPCNetworkParams().setSlobroksConfig(server.slobroksConfig());
         SharedMessageBus mbus = SharedMessageBus.newInstance(mbusParams, netParams);
         session = mbus.newSourceSession(new SourceSessionParams());
         client = new MbusClient(session);
@@ -128,7 +128,4 @@ public class ClientTestDriver {
         return new ClientTestDriver(RemoteServer.newInstanceWithInternSlobrok(), protocol);
     }
 
-    public static ClientTestDriver newInstanceWithExternSlobrok(String slobrokId) {
-        return new ClientTestDriver(RemoteServer.newInstanceWithExternSlobrok(slobrokId), new SimpleProtocol());
-    }
 }
diff --git a/container-messagebus/src/main/java/com/yahoo/messagebus/jdisc/test/RemoteClient.java b/container-messagebus/src/main/java/com/yahoo/messagebus/jdisc/test/RemoteClient.java
index 57d0abd980b..6cd8fb8f34d 100644
--- a/container-messagebus/src/main/java/com/yahoo/messagebus/jdisc/test/RemoteClient.java
+++ b/container-messagebus/src/main/java/com/yahoo/messagebus/jdisc/test/RemoteClient.java
@@ -1,9 +1,17 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.messagebus.jdisc.test;
 
+import com.yahoo.cloud.config.SlobroksConfig;
 import com.yahoo.jrt.ListenFailedException;
 import com.yahoo.jrt.slobrok.server.Slobrok;
-import com.yahoo.messagebus.*;
+import com.yahoo.messagebus.Message;
+import com.yahoo.messagebus.MessageBus;
+import com.yahoo.messagebus.MessageBusParams;
+import com.yahoo.messagebus.Protocol;
+import com.yahoo.messagebus.Reply;
+import com.yahoo.messagebus.Result;
+import com.yahoo.messagebus.SourceSession;
+import com.yahoo.messagebus.SourceSessionParams;
 import com.yahoo.messagebus.network.local.LocalNetwork;
 import com.yahoo.messagebus.network.rpc.RPCNetwork;
 import com.yahoo.messagebus.network.rpc.RPCNetworkParams;
@@ -17,16 +25,14 @@ import java.util.concurrent.TimeUnit;
 public class RemoteClient {
 
     private final Slobrok slobrok;
-    private final String slobrokId;
     private final MessageBus mbus;
     private final ReplyQueue queue = new ReplyQueue();
     private final SourceSession session;
 
-    private RemoteClient(Slobrok slobrok, String slobrokId, Protocol protocol, boolean network) {
-        this.slobrok = slobrok;
-        this.slobrokId = slobrok != null ? slobrok.configId() : slobrokId;
+    private RemoteClient(Protocol protocol, boolean network) {
+        this.slobrok = newSlobrok();
         mbus = network
-               ? new MessageBus(new RPCNetwork(new RPCNetworkParams().setSlobrokConfigId(this.slobrokId)),
+               ? new MessageBus(new RPCNetwork(new RPCNetworkParams().setSlobroksConfig(slobroksConfig())),
                                 new MessageBusParams().addProtocol(protocol))
                : new MessageBus(new LocalNetwork(), new MessageBusParams().addProtocol(protocol));
         session = mbus.createSourceSession(new SourceSessionParams().setThrottlePolicy(null).setReplyHandler(queue));
@@ -40,28 +46,22 @@ public class RemoteClient {
         return queue.awaitReply(timeout, unit);
     }
 
-    public String slobrokId() {
-        return slobrokId;
+    public SlobroksConfig slobroksConfig() {
+        return TestUtils.configFor(slobrok);
     }
 
     public void close() {
         session.destroy();
         mbus.destroy();
-        if (slobrok != null) {
-            slobrok.stop();
-        }
+        slobrok.stop();
     }
 
     public static RemoteClient newInstanceWithInternSlobrok(boolean network) {
-        return new RemoteClient(newSlobrok(), null, new SimpleProtocol(), network);
-    }
-
-    public static RemoteClient newInstanceWithExternSlobrok(String slobrokId, boolean network) {
-        return new RemoteClient(null, slobrokId, new SimpleProtocol(), network);
+        return new RemoteClient(new SimpleProtocol(), network);
     }
 
     public static RemoteClient newInstanceWithProtocolAndInternSlobrok(Protocol protocol, boolean network) {
-        return new RemoteClient(newSlobrok(), null, protocol, network);
+        return new RemoteClient(protocol, network);
     }
 
     private static Slobrok newSlobrok() {
diff --git a/container-messagebus/src/main/java/com/yahoo/messagebus/jdisc/test/RemoteServer.java b/container-messagebus/src/main/java/com/yahoo/messagebus/jdisc/test/RemoteServer.java
index 1f0f82c4903..0fb23e33709 100644
--- a/container-messagebus/src/main/java/com/yahoo/messagebus/jdisc/test/RemoteServer.java
+++ b/container-messagebus/src/main/java/com/yahoo/messagebus/jdisc/test/RemoteServer.java
@@ -1,9 +1,16 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.messagebus.jdisc.test;
 
+import com.yahoo.cloud.config.SlobroksConfig;
 import com.yahoo.jrt.ListenFailedException;
 import com.yahoo.jrt.slobrok.server.Slobrok;
-import com.yahoo.messagebus.*;
+import com.yahoo.messagebus.DestinationSession;
+import com.yahoo.messagebus.DestinationSessionParams;
+import com.yahoo.messagebus.Message;
+import com.yahoo.messagebus.MessageBus;
+import com.yahoo.messagebus.MessageBusParams;
+import com.yahoo.messagebus.Protocol;
+import com.yahoo.messagebus.Reply;
 import com.yahoo.messagebus.network.Identity;
 import com.yahoo.messagebus.network.rpc.RPCNetwork;
 import com.yahoo.messagebus.network.rpc.RPCNetworkParams;
@@ -17,16 +24,14 @@ import java.util.concurrent.TimeUnit;
 public class RemoteServer {
 
     private final Slobrok slobrok;
-    private final String slobrokId;
     private final MessageBus mbus;
     private final MessageQueue queue = new MessageQueue();
     private final DestinationSession session;
 
-    private RemoteServer(Slobrok slobrok, String slobrokId, Protocol protocol, String identity) {
-        this.slobrok = slobrok;
-        this.slobrokId = slobrok != null ? slobrok.configId() : slobrokId;
+    private RemoteServer(Protocol protocol, String identity) {
+        this.slobrok = newSlobrok();
         mbus = new MessageBus(new RPCNetwork(new RPCNetworkParams()
-                                                     .setSlobrokConfigId(this.slobrokId)
+                                                     .setSlobroksConfig(slobroksConfig())
                                                      .setIdentity(new Identity(identity))),
                               new MessageBusParams().addProtocol(protocol));
         session = mbus.createDestinationSession(new DestinationSessionParams().setMessageHandler(queue));
@@ -48,32 +53,22 @@ public class RemoteServer {
         session.reply(reply);
     }
 
-    public String slobrokId() {
-        return slobrokId;
+    public SlobroksConfig slobroksConfig() {
+        return TestUtils.configFor(slobrok);
     }
 
     public void close() {
         session.destroy();
         mbus.destroy();
-        if (slobrok != null) {
-            slobrok.stop();
-        }
+        slobrok.stop();
     }
 
     public static RemoteServer newInstanceWithInternSlobrok() {
-        return new RemoteServer(newSlobrok(), null, new SimpleProtocol(), "remote");
-    }
-
-    public static RemoteServer newInstanceWithExternSlobrok(String slobrokId) {
-        return new RemoteServer(null, slobrokId, new SimpleProtocol(), "remote");
-    }
-
-    public static RemoteServer newInstance(String slobrokId, String identity, Protocol protocol) {
-        return new RemoteServer(null, slobrokId, protocol, identity);
+        return new RemoteServer(new SimpleProtocol(), "remote");
     }
 
-    public static RemoteServer newInstanceWithProtocol(Protocol protocol) {
-        return new RemoteServer(newSlobrok(), null, protocol, "remote");
+    public static RemoteServer newInstance(String identity, Protocol protocol) {
+        return new RemoteServer(protocol, identity);
     }
 
     private static Slobrok newSlobrok() {
diff --git a/container-messagebus/src/main/java/com/yahoo/messagebus/jdisc/test/ServerTestDriver.java b/container-messagebus/src/main/java/com/yahoo/messagebus/jdisc/test/ServerTestDriver.java
index e59db28e886..fa0dd37ed13 100644
--- a/container-messagebus/src/main/java/com/yahoo/messagebus/jdisc/test/ServerTestDriver.java
+++ b/container-messagebus/src/main/java/com/yahoo/messagebus/jdisc/test/ServerTestDriver.java
@@ -42,7 +42,7 @@ public class ServerTestDriver {
         }
 
         MessageBusParams mbusParams = new MessageBusParams().addProtocol(protocol);
-        RPCNetworkParams netParams = new RPCNetworkParams().setSlobrokConfigId(client.slobrokId());
+        RPCNetworkParams netParams = new RPCNetworkParams().setSlobroksConfig(client.slobroksConfig());
         SharedMessageBus mbus = SharedMessageBus.newInstance(mbusParams, netParams);
         ServerSession session = mbus.newDestinationSession(new DestinationSessionParams());
         server = new MbusServer(driver, session);
@@ -130,13 +130,6 @@ public class ServerTestDriver {
                                     guiceModules);
     }
 
-    public static ServerTestDriver newInstanceWithExternSlobrok(String slobrokId, RequestHandler requestHandler,
-                                                                boolean network, Module... guiceModules)
-    {
-        return new ServerTestDriver(RemoteClient.newInstanceWithExternSlobrok(slobrokId, network),
-                                    true, requestHandler, new SimpleProtocol(), guiceModules);
-    }
-
     public static ServerTestDriver newInactiveInstance(boolean network, Module... guiceModules) {
         return new ServerTestDriver(RemoteClient.newInstanceWithInternSlobrok(network), false, null,
                                     new SimpleProtocol(), guiceModules);
diff --git a/container-messagebus/src/main/java/com/yahoo/messagebus/jdisc/test/TestUtils.java b/container-messagebus/src/main/java/com/yahoo/messagebus/jdisc/test/TestUtils.java
new file mode 100644
index 00000000000..85ad241259f
--- /dev/null
+++ b/container-messagebus/src/main/java/com/yahoo/messagebus/jdisc/test/TestUtils.java
@@ -0,0 +1,21 @@
+// Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.messagebus.jdisc.test;
+
+import com.yahoo.cloud.config.SlobroksConfig;
+import com.yahoo.jrt.Spec;
+import com.yahoo.jrt.slobrok.server.Slobrok;
+
+/**
+ * @author jonmv
+ */
+public class TestUtils {
+
+    private TestUtils() { }
+
+    public static SlobroksConfig configFor(Slobrok slobrok) {
+        return new SlobroksConfig.Builder().slobrok(new SlobroksConfig.Slobrok.Builder()
+                                                            .connectionspec(new Spec("localhost", slobrok.port()).toString()))
+                                           .build();
+    }
+
+}
diff --git a/container-messagebus/src/main/java/com/yahoo/messagebus/shared/NullNetwork.java b/container-messagebus/src/main/java/com/yahoo/messagebus/shared/NullNetwork.java
index ad58d6b9a5e..a7cf5fec7d1 100644
--- a/container-messagebus/src/main/java/com/yahoo/messagebus/shared/NullNetwork.java
+++ b/container-messagebus/src/main/java/com/yahoo/messagebus/shared/NullNetwork.java
@@ -12,9 +12,9 @@ import java.util.List;
 /**
  * <p>Used by SharedMessageBus as a network when the container runs in LocalApplication with no network services.</p>
  *
- * @author <a href="mailto:vegardh@yahoo-inc.com">Vegard Havdal</a>
+ * @author Vegard Havdal
  */
-class NullNetwork implements Network {
+public class NullNetwork implements Network {
 
     @Override
     public boolean waitUntilReady(double seconds) {
diff --git a/container-messagebus/src/main/java/com/yahoo/messagebus/shared/ServerSession.java b/container-messagebus/src/main/java/com/yahoo/messagebus/shared/ServerSession.java
index 56713815c7a..4cd4a776292 100644
--- a/container-messagebus/src/main/java/com/yahoo/messagebus/shared/ServerSession.java
+++ b/container-messagebus/src/main/java/com/yahoo/messagebus/shared/ServerSession.java
@@ -10,13 +10,16 @@ import com.yahoo.messagebus.Reply;
  */
 public interface ServerSession extends SharedResource {
 
-    public MessageHandler getMessageHandler();
+    MessageHandler getMessageHandler();
 
-    public void setMessageHandler(MessageHandler msgHandler);
+    void setMessageHandler(MessageHandler msgHandler);
 
-    public void sendReply(Reply reply);
+    void sendReply(Reply reply);
 
-    public String connectionSpec();
+    String connectionSpec();
+
+    String name();
+
+    void close();
 
-    public String name();
 }
diff --git a/container-messagebus/src/main/java/com/yahoo/messagebus/shared/SharedDestinationSession.java b/container-messagebus/src/main/java/com/yahoo/messagebus/shared/SharedDestinationSession.java
index 7da164757cd..5a9cd39c5b4 100644
--- a/container-messagebus/src/main/java/com/yahoo/messagebus/shared/SharedDestinationSession.java
+++ b/container-messagebus/src/main/java/com/yahoo/messagebus/shared/SharedDestinationSession.java
@@ -77,6 +77,11 @@ public class SharedDestinationSession extends AbstractResource implements Messag
     }
 
     @Override
+    public void close() {
+        session.destroy();
+    }
+
+    @Override
     protected void destroy() {
         log.log(Level.FINE, "Destroying shared destination session.");
         session.destroy();
diff --git a/container-messagebus/src/main/java/com/yahoo/messagebus/shared/SharedIntermediateSession.java b/container-messagebus/src/main/java/com/yahoo/messagebus/shared/SharedIntermediateSession.java
index 5c9fab46e34..64cc1aaf510 100644
--- a/container-messagebus/src/main/java/com/yahoo/messagebus/shared/SharedIntermediateSession.java
+++ b/container-messagebus/src/main/java/com/yahoo/messagebus/shared/SharedIntermediateSession.java
@@ -96,6 +96,11 @@ public class SharedIntermediateSession extends AbstractResource
     }
 
     @Override
+    public void close() {
+        session.destroy();
+    }
+
+    @Override
     protected void destroy() {
         log.log(Level.FINE, "Destroying shared intermediate session.");
         session.destroy();
diff --git a/container-messagebus/src/main/java/com/yahoo/messagebus/shared/SharedMessageBus.java b/container-messagebus/src/main/java/com/yahoo/messagebus/shared/SharedMessageBus.java
index dd135a51378..39bd6e86aa2 100644
--- a/container-messagebus/src/main/java/com/yahoo/messagebus/shared/SharedMessageBus.java
+++ b/container-messagebus/src/main/java/com/yahoo/messagebus/shared/SharedMessageBus.java
@@ -3,7 +3,10 @@ package com.yahoo.messagebus.shared;
 
 import com.yahoo.config.subscription.ConfigGetter;
 import com.yahoo.jdisc.AbstractResource;
+
+import java.util.Objects;
 import java.util.logging.Level;
+
 import com.yahoo.messagebus.DestinationSessionParams;
 import com.yahoo.messagebus.IntermediateSessionParams;
 import com.yahoo.messagebus.MessageBus;
@@ -25,8 +28,7 @@ public class SharedMessageBus extends AbstractResource {
     private final MessageBus mbus;
 
     public SharedMessageBus(MessageBus mbus) {
-        mbus.getClass(); // throws NullPointerException
-        this.mbus = mbus;
+        this.mbus = Objects.requireNonNull(mbus);
     }
 
     public MessageBus messageBus() {
@@ -65,4 +67,6 @@ public class SharedMessageBus extends AbstractResource {
         }
         return new RPCNetwork(params);
     }
+
+
 }
diff --git a/container-messagebus/src/test/java/com/yahoo/container/jdisc/messagebus/MbusClientProviderTest.java b/container-messagebus/src/test/java/com/yahoo/container/jdisc/messagebus/MbusClientProviderTest.java
index 6335cf01d8c..2a1c4e9a15a 100644
--- a/container-messagebus/src/test/java/com/yahoo/container/jdisc/messagebus/MbusClientProviderTest.java
+++ b/container-messagebus/src/test/java/com/yahoo/container/jdisc/messagebus/MbusClientProviderTest.java
@@ -1,9 +1,15 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.container.jdisc.messagebus;
 
+import com.yahoo.container.jdisc.ContainerMbusConfig;
 import com.yahoo.container.jdisc.config.SessionConfig;
-import com.yahoo.container.jdisc.messagebus.MbusClientProvider;
-import com.yahoo.container.jdisc.messagebus.SessionCache;
+import com.yahoo.document.config.DocumentmanagerConfig;
+import com.yahoo.documentapi.messagebus.protocol.DocumentProtocolPoliciesConfig;
+import com.yahoo.messagebus.MessagebusConfig;
+import com.yahoo.messagebus.network.NetworkMultiplexer;
+import com.yahoo.messagebus.shared.NullNetwork;
+import com.yahoo.vespa.config.content.DistributionConfig;
+import com.yahoo.vespa.config.content.LoadTypeConfig;
 import org.junit.Test;
 
 import static org.junit.Assert.assertNotNull;
@@ -30,7 +36,14 @@ public class MbusClientProviderTest {
     }
 
     private void testClient(SessionConfig config) {
-        MbusClientProvider p = new MbusClientProvider(new SessionCache("dir:src/test/resources/config/clientprovider"), config);
+        SessionCache cache = new SessionCache(NetworkMultiplexer.dedicated(new NullNetwork()),
+                                              new ContainerMbusConfig.Builder().build(),
+                                              new DocumentmanagerConfig.Builder().build(),
+                                              new LoadTypeConfig.Builder().build(),
+                                              new MessagebusConfig.Builder().build(),
+                                              new DocumentProtocolPoliciesConfig.Builder().build(),
+                                              new DistributionConfig.Builder().build());
+        MbusClientProvider p = new MbusClientProvider(cache, config);
         assertNotNull(p.get());
         p.deconstruct();
     }
diff --git a/container-messagebus/src/test/java/com/yahoo/container/jdisc/messagebus/MbusSessionKeyTestCase.java b/container-messagebus/src/test/java/com/yahoo/container/jdisc/messagebus/MbusSessionKeyTestCase.java
index 89bc5b9cecd..709f78f5cf0 100644
--- a/container-messagebus/src/test/java/com/yahoo/container/jdisc/messagebus/MbusSessionKeyTestCase.java
+++ b/container-messagebus/src/test/java/com/yahoo/container/jdisc/messagebus/MbusSessionKeyTestCase.java
@@ -17,7 +17,7 @@ import static org.junit.Assert.assertTrue;
 /**
  * Check the completeness of the mbus session key classes.
  *
- * @author <a href="mailto:steinar@yahoo-inc.com">Steinar Knutsen</a>
+ * @author Steinar Knutsen
  */
 public class MbusSessionKeyTestCase {
 
diff --git a/container-messagebus/src/test/java/com/yahoo/messagebus/jdisc/MbusServerTestCase.java b/container-messagebus/src/test/java/com/yahoo/messagebus/jdisc/MbusServerTestCase.java
index 9d45d2e7abf..6ebb41c4ab7 100644
--- a/container-messagebus/src/test/java/com/yahoo/messagebus/jdisc/MbusServerTestCase.java
+++ b/container-messagebus/src/test/java/com/yahoo/messagebus/jdisc/MbusServerTestCase.java
@@ -331,9 +331,7 @@ public class MbusServerTestCase {
         int refCount = 1;
 
         @Override
-        public void sendReply(Reply reply) {
-
-        }
+        public void sendReply(Reply reply) { }
 
         @Override
         public MessageHandler getMessageHandler() {
@@ -341,9 +339,7 @@ public class MbusServerTestCase {
         }
 
         @Override
-        public void setMessageHandler(MessageHandler msgHandler) {
-
-        }
+        public void setMessageHandler(MessageHandler msgHandler) { }
 
         @Override
         public String connectionSpec() {
@@ -356,14 +352,12 @@ public class MbusServerTestCase {
         }
 
         @Override
+        public void close() { }
+
+        @Override
         public ResourceReference refer() {
             ++refCount;
-            return new ResourceReference() {
-                @Override
-                public void close() {
-                    --refCount;
-                }
-            };
+            return () -> --refCount;
         }
 
         @Override
diff --git a/container-messagebus/src/test/java/com/yahoo/messagebus/jdisc/test/ClientTestDriverTestCase.java b/container-messagebus/src/test/java/com/yahoo/messagebus/jdisc/test/ClientTestDriverTestCase.java
index ef290a070cb..d24acb9d0d8 100644
--- a/container-messagebus/src/test/java/com/yahoo/messagebus/jdisc/test/ClientTestDriverTestCase.java
+++ b/container-messagebus/src/test/java/com/yahoo/messagebus/jdisc/test/ClientTestDriverTestCase.java
@@ -23,10 +23,6 @@ public class ClientTestDriverTestCase {
         driver = ClientTestDriver.newInstanceWithProtocol(new SimpleProtocol());
         assertNotNull(driver);
         assertTrue(driver.close());
-
-        Slobrok slobrok = new Slobrok();
-        driver = ClientTestDriver.newInstanceWithExternSlobrok(slobrok.configId());
-        assertNotNull(driver);
-        assertTrue(driver.close());
     }
+
 }
diff --git a/container-messagebus/src/test/java/com/yahoo/messagebus/jdisc/test/ServerTestDriverTestCase.java b/container-messagebus/src/test/java/com/yahoo/messagebus/jdisc/test/ServerTestDriverTestCase.java
index f6ae2335d12..7b2c1b68549 100644
--- a/container-messagebus/src/test/java/com/yahoo/messagebus/jdisc/test/ServerTestDriverTestCase.java
+++ b/container-messagebus/src/test/java/com/yahoo/messagebus/jdisc/test/ServerTestDriverTestCase.java
@@ -24,11 +24,6 @@ public class ServerTestDriverTestCase {
         driver = ServerTestDriver.newInstanceWithProtocol(new SimpleProtocol(), new NonWorkingRequestHandler(), false);
         assertNotNull(driver);
         assertTrue(driver.close());
-
-        Slobrok slobrok = new Slobrok();
-        driver = ServerTestDriver.newInstanceWithExternSlobrok(slobrok.configId(), new NonWorkingRequestHandler(), false);
-        assertNotNull(driver);
-        assertTrue(driver.close());
     }
 
 }
diff --git a/container-messagebus/src/test/java/com/yahoo/messagebus/shared/SharedDestinationSessionTestCase.java b/container-messagebus/src/test/java/com/yahoo/messagebus/shared/SharedDestinationSessionTestCase.java
index 78e79da4b9f..759509946ce 100644
--- a/container-messagebus/src/test/java/com/yahoo/messagebus/shared/SharedDestinationSessionTestCase.java
+++ b/container-messagebus/src/test/java/com/yahoo/messagebus/shared/SharedDestinationSessionTestCase.java
@@ -1,12 +1,14 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.messagebus.shared;
 
+import com.yahoo.cloud.config.SlobroksConfig;
 import com.yahoo.jrt.ListenFailedException;
 import com.yahoo.jrt.slobrok.server.Slobrok;
 import com.yahoo.messagebus.*;
 import com.yahoo.messagebus.jdisc.test.MessageQueue;
 import com.yahoo.messagebus.jdisc.test.RemoteClient;
 import com.yahoo.messagebus.jdisc.test.ReplyQueue;
+import com.yahoo.messagebus.jdisc.test.TestUtils;
 import com.yahoo.messagebus.network.rpc.RPCNetworkParams;
 import com.yahoo.messagebus.routing.Route;
 import com.yahoo.messagebus.test.SimpleMessage;
@@ -98,7 +100,7 @@ public class SharedDestinationSessionTestCase {
         RemoteClient client = RemoteClient.newInstanceWithInternSlobrok(true);
         MessageQueue queue = new MessageQueue();
         DestinationSessionParams params = new DestinationSessionParams().setMessageHandler(queue);
-        SharedDestinationSession session = newDestinationSession(client.slobrokId(), params);
+        SharedDestinationSession session = newDestinationSession(client.slobroksConfig(), params);
         Route route = Route.parse(session.connectionSpec());
 
         assertTrue(client.sendMessage(new SimpleMessage("foo").setRoute(route)).isAccepted());
@@ -120,11 +122,11 @@ public class SharedDestinationSessionTestCase {
         } catch (ListenFailedException e) {
             fail();
         }
-        return newDestinationSession(slobrok.configId(), new DestinationSessionParams());
+        return newDestinationSession(TestUtils.configFor(slobrok), new DestinationSessionParams());
     }
 
-    private static SharedDestinationSession newDestinationSession(String slobrokId, DestinationSessionParams params) {
-        RPCNetworkParams netParams = new RPCNetworkParams().setSlobrokConfigId(slobrokId);
+    private static SharedDestinationSession newDestinationSession(SlobroksConfig slobroksConfig, DestinationSessionParams params) {
+        RPCNetworkParams netParams = new RPCNetworkParams().setSlobroksConfig(slobroksConfig);
         MessageBusParams mbusParams = new MessageBusParams().addProtocol(new SimpleProtocol());
         SharedMessageBus mbus = SharedMessageBus.newInstance(mbusParams, netParams);
         SharedDestinationSession session = mbus.newDestinationSession(params);
diff --git a/container-messagebus/src/test/java/com/yahoo/messagebus/shared/SharedIntermediateSessionTestCase.java b/container-messagebus/src/test/java/com/yahoo/messagebus/shared/SharedIntermediateSessionTestCase.java
index 87958415149..ca8301d1ea9 100644
--- a/container-messagebus/src/test/java/com/yahoo/messagebus/shared/SharedIntermediateSessionTestCase.java
+++ b/container-messagebus/src/test/java/com/yahoo/messagebus/shared/SharedIntermediateSessionTestCase.java
@@ -1,6 +1,7 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.messagebus.shared;
 
+import com.yahoo.cloud.config.SlobroksConfig;
 import com.yahoo.jrt.ListenFailedException;
 import com.yahoo.jrt.slobrok.server.Slobrok;
 import com.yahoo.messagebus.*;
@@ -8,6 +9,7 @@ import com.yahoo.messagebus.jdisc.test.MessageQueue;
 import com.yahoo.messagebus.jdisc.test.RemoteClient;
 import com.yahoo.messagebus.jdisc.test.RemoteServer;
 import com.yahoo.messagebus.jdisc.test.ReplyQueue;
+import com.yahoo.messagebus.jdisc.test.TestUtils;
 import com.yahoo.messagebus.network.local.LocalNetwork;
 import com.yahoo.messagebus.network.local.LocalWire;
 import com.yahoo.messagebus.network.rpc.RPCNetworkParams;
@@ -77,7 +79,7 @@ public class SharedIntermediateSessionTestCase {
     public void requireThatReplyHandlerCanNotBeSet() throws ListenFailedException {
         Slobrok slobrok = new Slobrok();
         try {
-            newIntermediateSession(slobrok.configId(),
+            newIntermediateSession(TestUtils.configFor(slobrok),
                                    new IntermediateSessionParams().setReplyHandler(new ReplyQueue()),
                                    false);
             fail();
@@ -111,7 +113,7 @@ public class SharedIntermediateSessionTestCase {
     @Test
     public void requireThatSessionCanSendMessage() throws InterruptedException {
         RemoteServer server = RemoteServer.newInstanceWithInternSlobrok();
-        SharedIntermediateSession session = newIntermediateSession(server.slobrokId(),
+        SharedIntermediateSession session = newIntermediateSession(server.slobroksConfig(),
                                                                    new IntermediateSessionParams(),
                                                                    true);
         ReplyQueue queue = new ReplyQueue();
@@ -134,7 +136,7 @@ public class SharedIntermediateSessionTestCase {
         RemoteClient client = RemoteClient.newInstanceWithInternSlobrok(true);
         MessageQueue queue = new MessageQueue();
         IntermediateSessionParams params = new IntermediateSessionParams().setMessageHandler(queue);
-        SharedIntermediateSession session = newIntermediateSession(client.slobrokId(), params, true);
+        SharedIntermediateSession session = newIntermediateSession(client.slobroksConfig(), params, true);
         Route route = Route.parse(session.connectionSpec());
 
         assertTrue(client.sendMessage(new SimpleMessage("foo").setRoute(route)).isAccepted());
@@ -156,13 +158,13 @@ public class SharedIntermediateSessionTestCase {
         } catch (ListenFailedException e) {
             fail();
         }
-        return newIntermediateSession(slobrok.configId(), new IntermediateSessionParams(), network);
+        return newIntermediateSession(TestUtils.configFor(slobrok), new IntermediateSessionParams(), network);
     }
 
-    private static SharedIntermediateSession newIntermediateSession(String slobrokId,
+    private static SharedIntermediateSession newIntermediateSession(SlobroksConfig slobroksConfig,
                                                                     IntermediateSessionParams params,
                                                                     boolean network) {
-        RPCNetworkParams netParams = new RPCNetworkParams().setSlobrokConfigId(slobrokId);
+        RPCNetworkParams netParams = new RPCNetworkParams().setSlobroksConfig(slobroksConfig);
         MessageBusParams mbusParams = new MessageBusParams().addProtocol(new SimpleProtocol());
         SharedMessageBus mbus = network
                                 ? SharedMessageBus.newInstance(mbusParams, netParams)
diff --git a/container-messagebus/src/test/java/com/yahoo/messagebus/shared/SharedSourceSessionTestCase.java b/container-messagebus/src/test/java/com/yahoo/messagebus/shared/SharedSourceSessionTestCase.java
index 1f0966fc961..7a4a3d17170 100644
--- a/container-messagebus/src/test/java/com/yahoo/messagebus/shared/SharedSourceSessionTestCase.java
+++ b/container-messagebus/src/test/java/com/yahoo/messagebus/shared/SharedSourceSessionTestCase.java
@@ -1,6 +1,7 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.messagebus.shared;
 
+import com.yahoo.cloud.config.SlobroksConfig;
 import com.yahoo.jrt.ListenFailedException;
 import com.yahoo.jrt.slobrok.server.Slobrok;
 import com.yahoo.messagebus.Message;
@@ -8,6 +9,7 @@ import com.yahoo.messagebus.MessageBusParams;
 import com.yahoo.messagebus.SourceSessionParams;
 import com.yahoo.messagebus.jdisc.test.RemoteServer;
 import com.yahoo.messagebus.jdisc.test.ReplyQueue;
+import com.yahoo.messagebus.jdisc.test.TestUtils;
 import com.yahoo.messagebus.network.rpc.RPCNetworkParams;
 import com.yahoo.messagebus.routing.Route;
 import com.yahoo.messagebus.test.SimpleMessage;
@@ -59,7 +61,7 @@ public class SharedSourceSessionTestCase {
     @Test
     public void requireThatSessionCanSendMessage() throws InterruptedException {
         RemoteServer server = RemoteServer.newInstanceWithInternSlobrok();
-        SharedSourceSession session = newSourceSession(server.slobrokId(),
+        SharedSourceSession session = newSourceSession(server.slobroksConfig(),
                                                        new SourceSessionParams());
         ReplyQueue queue = new ReplyQueue();
         Message msg = new SimpleMessage("foo").setRoute(Route.parse(server.connectionSpec()));
@@ -80,11 +82,11 @@ public class SharedSourceSessionTestCase {
         } catch (ListenFailedException e) {
             fail();
         }
-        return newSourceSession(slobrok.configId(), params);
+        return newSourceSession(TestUtils.configFor(slobrok), params);
     }
 
-    private static SharedSourceSession newSourceSession(String slobrokId, SourceSessionParams params) {
-        RPCNetworkParams netParams = new RPCNetworkParams().setSlobrokConfigId(slobrokId);
+    private static SharedSourceSession newSourceSession(SlobroksConfig slobroksConfig, SourceSessionParams params) {
+        RPCNetworkParams netParams = new RPCNetworkParams().setSlobroksConfig(slobroksConfig);
         MessageBusParams mbusParams = new MessageBusParams().addProtocol(new SimpleProtocol());
         SharedMessageBus mbus = SharedMessageBus.newInstance(mbusParams, netParams);
         SharedSourceSession session = mbus.newSourceSession(params);
diff --git a/container-messagebus/src/test/resources/config/clientprovider/container-mbus.cfg b/container-messagebus/src/test/resources/config/clientprovider/container-mbus.cfg
deleted file mode 100644
index e69de29bb2d..00000000000
--- a/container-messagebus/src/test/resources/config/clientprovider/container-mbus.cfg
+++ /dev/null
diff --git a/container-messagebus/src/test/resources/config/clientprovider/documentmanager.cfg b/container-messagebus/src/test/resources/config/clientprovider/documentmanager.cfg
deleted file mode 100644
index e69de29bb2d..00000000000
--- a/container-messagebus/src/test/resources/config/clientprovider/documentmanager.cfg
+++ /dev/null
diff --git a/container-messagebus/src/test/resources/config/clientprovider/load-type.cfg b/container-messagebus/src/test/resources/config/clientprovider/load-type.cfg
deleted file mode 100644
index e69de29bb2d..00000000000
--- a/container-messagebus/src/test/resources/config/clientprovider/load-type.cfg
+++ /dev/null
diff --git a/container-messagebus/src/test/resources/config/clientprovider/messagebus.cfg b/container-messagebus/src/test/resources/config/clientprovider/messagebus.cfg
deleted file mode 100644
index e69de29bb2d..00000000000
--- a/container-messagebus/src/test/resources/config/clientprovider/messagebus.cfg
+++ /dev/null
diff --git a/container-messagebus/src/test/resources/config/clientprovider/slobroks.cfg b/container-messagebus/src/test/resources/config/clientprovider/slobroks.cfg
deleted file mode 100644
index e69de29bb2d..00000000000
--- a/container-messagebus/src/test/resources/config/clientprovider/slobroks.cfg
+++ /dev/null
diff --git a/docproc/src/test/java/com/yahoo/docproc/jdisc/DocumentProcessingHandlerAllMessageTypesTestCase.java b/docproc/src/test/java/com/yahoo/docproc/jdisc/DocumentProcessingHandlerAllMessageTypesTestCase.java
index c508e7da61d..268a40f04c9 100644
--- a/docproc/src/test/java/com/yahoo/docproc/jdisc/DocumentProcessingHandlerAllMessageTypesTestCase.java
+++ b/docproc/src/test/java/com/yahoo/docproc/jdisc/DocumentProcessingHandlerAllMessageTypesTestCase.java
@@ -36,7 +36,7 @@ import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.assertNotNull;
 
 /**
- * @author <a href="mailto:einarmr@yahoo-inc.com">Einar M R Rosenvinge</a>
+ * @author Einar M R Rosenvinge
  */
 public class DocumentProcessingHandlerAllMessageTypesTestCase extends DocumentProcessingHandlerTestBase {
 
diff --git a/docproc/src/test/java/com/yahoo/docproc/jdisc/DocumentProcessingHandlerTestBase.java b/docproc/src/test/java/com/yahoo/docproc/jdisc/DocumentProcessingHandlerTestBase.java
index 05009f484c8..a2b60bb779c 100644
--- a/docproc/src/test/java/com/yahoo/docproc/jdisc/DocumentProcessingHandlerTestBase.java
+++ b/docproc/src/test/java/com/yahoo/docproc/jdisc/DocumentProcessingHandlerTestBase.java
@@ -1,11 +1,14 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.docproc.jdisc;
 
+import com.yahoo.cloud.config.SlobroksConfig;
 import com.yahoo.collections.Pair;
 import com.yahoo.component.ComponentId;
 import com.yahoo.component.provider.ComponentRegistry;
 import com.yahoo.container.core.document.ContainerDocumentConfig;
+import com.yahoo.container.jdisc.ContainerMbusConfig;
 import com.yahoo.container.jdisc.messagebus.MbusServerProvider;
+import com.yahoo.container.jdisc.messagebus.NetworkMultiplexerProvider;
 import com.yahoo.container.jdisc.messagebus.SessionCache;
 import com.yahoo.docproc.CallStack;
 import com.yahoo.docproc.DocprocService;
@@ -13,19 +16,26 @@ import com.yahoo.docproc.jdisc.messagebus.MbusRequestContext;
 
 import com.yahoo.document.DocumentType;
 import com.yahoo.document.DocumentTypeManager;
+import com.yahoo.document.config.DocumentmanagerConfig;
 import com.yahoo.documentapi.messagebus.loadtypes.LoadType;
 import com.yahoo.documentapi.messagebus.protocol.DocumentMessage;
 import com.yahoo.documentapi.messagebus.protocol.DocumentProtocol;
+import com.yahoo.documentapi.messagebus.protocol.DocumentProtocolPoliciesConfig;
 import com.yahoo.jdisc.AbstractResource;
 import com.yahoo.jdisc.ReferencedResource;
 import com.yahoo.jdisc.application.ContainerBuilder;
+import com.yahoo.messagebus.MessagebusConfig;
 import com.yahoo.messagebus.Protocol;
 import com.yahoo.messagebus.SourceSessionParams;
 import com.yahoo.messagebus.jdisc.MbusClient;
 import com.yahoo.messagebus.jdisc.test.RemoteServer;
 import com.yahoo.messagebus.jdisc.test.ServerTestDriver;
+import com.yahoo.messagebus.network.NetworkMultiplexer;
+import com.yahoo.messagebus.network.rpc.RPCNetwork;
 import com.yahoo.messagebus.routing.Route;
 import com.yahoo.messagebus.shared.SharedSourceSession;
+import com.yahoo.vespa.config.content.DistributionConfig;
+import com.yahoo.vespa.config.content.LoadTypeConfig;
 import org.junit.After;
 import org.junit.Before;
 
@@ -52,8 +62,13 @@ public abstract class DocumentProcessingHandlerTestBase {
 
         driver = ServerTestDriver.newInactiveInstanceWithProtocol(protocol, true);
 
-        sessionCache =
-                new SessionCache("raw:", driver.client().slobrokId(), "test", "raw:", null, "raw:", documentTypeManager);
+        RPCNetwork net = new RPCNetwork(NetworkMultiplexerProvider.asParameters(new ContainerMbusConfig.Builder().build(),
+                                                                                driver.client().slobroksConfig(),
+                                                                                "test"));
+        sessionCache = new SessionCache(NetworkMultiplexer.dedicated(net),
+                                        new ContainerMbusConfig.Builder().build(),
+                                        new MessagebusConfig.Builder().build(),
+                                        protocol);
 
         ContainerBuilder builder = driver.parent().newContainerBuilder();
         ComponentRegistry<DocprocService> registry = new ComponentRegistry<>();
@@ -102,7 +117,7 @@ public abstract class DocumentProcessingHandlerTestBase {
             resource.release();
         }
 
-        remoteServer = RemoteServer.newInstance(driver.client().slobrokId(), "foobar", protocol);
+        remoteServer = RemoteServer.newInstance("foobar", protocol);
     }
 
     @After
diff --git a/messagebus/abi-spec.json b/messagebus/abi-spec.json
index f3e7c5664d6..85c1eaa4f09 100644
--- a/messagebus/abi-spec.json
+++ b/messagebus/abi-spec.json
@@ -311,6 +311,7 @@
       "public void register(com.yahoo.messagebus.MessageBus$SendBlockedMessages)",
       "public void <init>(com.yahoo.messagebus.network.Network, java.util.List)",
       "public void <init>(com.yahoo.messagebus.network.Network, com.yahoo.messagebus.MessageBusParams)",
+      "public void <init>(com.yahoo.messagebus.network.NetworkMultiplexer, com.yahoo.messagebus.MessageBusParams)",
       "public boolean destroy()",
       "public void sync()",
       "public com.yahoo.messagebus.SourceSession createSourceSession(com.yahoo.messagebus.ReplyHandler)",
@@ -326,7 +327,6 @@
       "public void deliverMessage(com.yahoo.messagebus.Message, java.lang.String)",
       "public void putProtocol(com.yahoo.messagebus.Protocol)",
       "public com.yahoo.messagebus.Protocol getProtocol(com.yahoo.text.Utf8Array)",
-      "public com.yahoo.messagebus.Protocol getProtocol(com.yahoo.text.Utf8String)",
       "public void deliverReply(com.yahoo.messagebus.Reply, com.yahoo.messagebus.ReplyHandler)",
       "public void setupRouting(com.yahoo.messagebus.routing.RoutingSpec)",
       "public com.yahoo.messagebus.routing.Resender getResender()",
diff --git a/messagebus/src/main/java/com/yahoo/messagebus/MessageBus.java b/messagebus/src/main/java/com/yahoo/messagebus/MessageBus.java
index 99d9a6d6483..4b674b86aeb 100644
--- a/messagebus/src/main/java/com/yahoo/messagebus/MessageBus.java
+++ b/messagebus/src/main/java/com/yahoo/messagebus/MessageBus.java
@@ -1,10 +1,10 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.messagebus;
 
-import com.yahoo.concurrent.CopyOnWriteHashMap;
 import com.yahoo.concurrent.SystemTimer;
 import java.util.logging.Level;
 import com.yahoo.messagebus.network.Network;
+import com.yahoo.messagebus.network.NetworkMultiplexer;
 import com.yahoo.messagebus.network.NetworkOwner;
 import com.yahoo.messagebus.routing.Resender;
 import com.yahoo.messagebus.routing.RetryPolicy;
@@ -64,7 +64,7 @@ public class MessageBus implements ConfigHandler, NetworkOwner, MessageHandler,
     private final ProtocolRepository protocolRepository = new ProtocolRepository();
     private final AtomicReference<Map<String, RoutingTable>> tablesRef = new AtomicReference<>(null);
     private final Map<String, MessageHandler> sessions = new ConcurrentHashMap<>();
-    private final Network net;
+    private final NetworkMultiplexer net;
     private final Messenger msn;
     private final Resender resender;
     private int maxPendingCount;
@@ -117,13 +117,25 @@ public class MessageBus implements ConfigHandler, NetworkOwner, MessageHandler,
 
     /**
      * <p>Constructs an instance of message bus. This requires a network object
-     * that it will associate with. This assignment may not change during the
-     * lifetime of this message bus.</p>
+     * that it will associate with. This assignment may not change during the lifetime
+     * of this message bus, and this bus will be the single owner of this net.</p>
      *
      * @param net    The network to associate with.
      * @param params The parameters that controls this bus.
      */
     public MessageBus(Network net, MessageBusParams params) {
+        this(NetworkMultiplexer.dedicated(net), params);
+    }
+
+    /**
+     * <p>Constructs an instance of message bus. This requires a network multiplexer
+     * that it will associate with. This assignment may not change during the
+     * lifetime of this message bus.</p>
+     *
+     * @param net    The network multiplexer to associate with.
+     * @param params The parameters that controls this bus.
+     */
+    public MessageBus(NetworkMultiplexer net, MessageBusParams params) {
         // Add all known protocols to the repository.
         maxPendingCount = params.getMaxPendingCount();
         maxPendingSize  = params.getMaxPendingSize();
@@ -134,7 +146,7 @@ public class MessageBus implements ConfigHandler, NetworkOwner, MessageHandler,
         // Attach and start network.
         this.net = net;
         net.attach(this);
-        if ( ! net.waitUntilReady(120))
+        if ( ! net.net().waitUntilReady(120))
             throw new IllegalStateException("Network failed to become ready in time.");
 
         // Start messenger.
@@ -167,7 +179,7 @@ public class MessageBus implements ConfigHandler, NetworkOwner, MessageHandler,
                 careTaker.join();
             } catch (InterruptedException e) { }
             protocolRepository.clearPolicyCache();
-            net.shutdown();
+            net.detach(this);
             msn.destroy();
             if (resender != null) {
                 resender.destroy();
@@ -186,7 +198,7 @@ public class MessageBus implements ConfigHandler, NetworkOwner, MessageHandler,
      */
     public void sync() {
         msn.sync();
-        net.sync();
+        net.net().sync();
     }
 
     /**
@@ -267,9 +279,7 @@ public class MessageBus implements ConfigHandler, NetworkOwner, MessageHandler,
         }
         IntermediateSession session = new IntermediateSession(this, params);
         sessions.put(params.getName(), session);
-        if (params.getBroadcastName()) {
-            net.registerSession(params.getName());
-        }
+        net.registerSession(params.getName(), this, params.getBroadcastName());
         return session;
     }
 
@@ -310,9 +320,7 @@ public class MessageBus implements ConfigHandler, NetworkOwner, MessageHandler,
         }
         DestinationSession session = new DestinationSession(this, params);
         sessions.put(params.getName(), session);
-        if (params.getBroadcastName()) {
-            net.registerSession(params.getName());
-        }
+        net.registerSession(params.getName(), this, params.getBroadcastName());
         return session;
     }
 
@@ -325,9 +333,7 @@ public class MessageBus implements ConfigHandler, NetworkOwner, MessageHandler,
      * @param broadcastName Whether or not session name was broadcast.
      */
     public synchronized void unregisterSession(String name, boolean broadcastName) {
-        if (broadcastName) {
-            net.unregisterSession(name);
-        }
+        net.unregisterSession(name, this, broadcastName);
         sessions.remove(name);
     }
 
@@ -371,7 +377,7 @@ public class MessageBus implements ConfigHandler, NetworkOwner, MessageHandler,
             deliverError(msg, ErrorCode.SEQUENCE_ERROR, "Bucket sequences not supported when resender is enabled.");
             return;
         }
-        SendProxy proxy = new SendProxy(this, net, resender);
+        SendProxy proxy = new SendProxy(this, net.net(), resender);
         msn.deliverMessage(msg, proxy);
     }
 
@@ -396,7 +402,7 @@ public class MessageBus implements ConfigHandler, NetworkOwner, MessageHandler,
         if (msgHandler == null) {
             deliverError(msg, ErrorCode.UNKNOWN_SESSION, "Session '" + session + "' does not exist.");
         } else if (!checkPending(msg)) {
-            deliverError(msg, ErrorCode.SESSION_BUSY, "Session '" + net.getConnectionSpec() + "/" + session +
+            deliverError(msg, ErrorCode.SESSION_BUSY, "Session '" + net.net().getConnectionSpec() + "/" + session +
                                                       "' is busy, try again later.");
         } else {
             msn.deliverMessage(msg, msgHandler);
@@ -419,11 +425,6 @@ public class MessageBus implements ConfigHandler, NetworkOwner, MessageHandler,
         return protocolRepository.getProtocol(name.toString());
     }
 
-    public Protocol getProtocol(Utf8String name) {
-        return getProtocol((Utf8Array)name);
-    }
-
-    @Override
     public void deliverReply(Reply reply, ReplyHandler handler) {
         msn.deliverReply(reply, handler);
     }
@@ -569,7 +570,7 @@ public class MessageBus implements ConfigHandler, NetworkOwner, MessageHandler,
      * @return The connection string.
      */
     public String getConnectionSpec() {
-        return net.getConnectionSpec();
+        return net.net().getConnectionSpec();
     }
 
     /**
@@ -608,5 +609,5 @@ public class MessageBus implements ConfigHandler, NetworkOwner, MessageHandler,
         }
 
     }
-}
 
+}
diff --git a/messagebus/src/main/java/com/yahoo/messagebus/Messenger.java b/messagebus/src/main/java/com/yahoo/messagebus/Messenger.java
index 0cc8310937b..871a8f2a0b4 100755
--- a/messagebus/src/main/java/com/yahoo/messagebus/Messenger.java
+++ b/messagebus/src/main/java/com/yahoo/messagebus/Messenger.java
@@ -128,7 +128,7 @@ public class Messenger implements Runnable {
      */
     public boolean destroy() {
         boolean done = false;
-        enqueue(Terminate.INSTANCE);
+        enqueue(TERMINATE);
         if (!destroyed.getAndSet(true)) {
             try {
                 synchronized (this) {
@@ -161,7 +161,7 @@ public class Messenger implements Runnable {
                     task = queue.poll();
                 }
             }
-            if (task == Terminate.INSTANCE) {
+            if (task == TERMINATE) {
                 break;
             }
             if (task != null) {
@@ -175,7 +175,7 @@ public class Messenger implements Runnable {
                 } catch (final Exception e) {
                     log.warning("An exception was thrown while destroying " + task.getClass().getName() + ": " +
                                 e.toString());
-                    log.warning("Someone, somewhere might have to wait indefinetly for something.");
+                    log.warning("Someone, somewhere might have to wait indefinitely for something.");
                 }
             }
             for (final Task child : children) {
@@ -235,18 +235,9 @@ public class Messenger implements Runnable {
         }
     }
 
-    private static class Terminate implements Task {
+    private static final Task TERMINATE = new Task() {
+        @Override public void run() { }
+        @Override public void destroy() { }
+    };
 
-        static final Terminate INSTANCE = new Terminate();
-
-        @Override
-        public void run() {
-            // empty
-        }
-
-        @Override
-        public void destroy() {
-            // empty
-        }
-    }
 }
diff --git a/messagebus/src/main/java/com/yahoo/messagebus/network/NetworkMultiplexer.java b/messagebus/src/main/java/com/yahoo/messagebus/network/NetworkMultiplexer.java
new file mode 100644
index 00000000000..5e6a8c7688e
--- /dev/null
+++ b/messagebus/src/main/java/com/yahoo/messagebus/network/NetworkMultiplexer.java
@@ -0,0 +1,143 @@
+// Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.messagebus.network;
+
+import com.yahoo.messagebus.Message;
+import com.yahoo.messagebus.Protocol;
+import com.yahoo.text.Utf8Array;
+
+import java.util.Map;
+import java.util.Queue;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.logging.Logger;
+
+/**
+ * A bridge between the reusable, singleton RPC network, and the generational message bus which uses this.
+ * The RPC network is required to be singular because of its unique resources, such as sockets.
+ * This is complicated by the message bus potentially existing in different graph generation at any point in
+ * time, with all copies potential users of the network interface, but where each message bus-registered session
+ * should belong to a single message bus. This class solves these problems by tracking which sessions are
+ * active in which message bus instance, and by (de)registering only when a session is registered to (no) message
+ * bus instances.
+ *
+ * In time, this should allow us to get rid of the shared-this-and-that in the container, too ...
+ *
+ * @author jonmv
+ */
+public class NetworkMultiplexer implements NetworkOwner {
+
+    private static final Logger log = Logger.getLogger(NetworkMultiplexer.class.getName());
+
+    private final Network net;
+    private final Queue<NetworkOwner> owners = new ConcurrentLinkedQueue<>();
+    private final Map<String, Queue<NetworkOwner>> sessions = new ConcurrentHashMap<>();
+    private final boolean shared;
+
+    private NetworkMultiplexer(Network net, boolean shared) {
+        net.attach(this);
+        this.net = net;
+        this.shared = shared;
+    }
+
+    /** Returns a network multiplexer which will be shared between several {@link NetworkOwner}s. */
+    public static NetworkMultiplexer shared(Network net) {
+        return new NetworkMultiplexer(net, true);
+    }
+
+    /** Returns a network multiplexer with a single {@link NetworkOwner}, which shuts down when this owner detaches. */
+    public static NetworkMultiplexer dedicated(Network net) {
+        return new NetworkMultiplexer(net, false);
+    }
+
+    public void registerSession(String session, NetworkOwner owner, boolean broadcast) {
+        sessions.compute(session, (name, owners) -> {
+            if (owners == null) {
+                owners = new ConcurrentLinkedQueue<>();
+                if (broadcast)
+                    net.registerSession(session);
+            }
+            else if (owners.contains(owner))
+                throw new IllegalArgumentException("Session '" + session + "' with owner '" + owner + "' already registered with this");
+
+            owners.add(owner);
+            return owners;
+        });
+    }
+
+    public void unregisterSession(String session, NetworkOwner owner, boolean broadcast) {
+        sessions.compute(session, (name, owners) -> {
+            if (owners == null || ! owners.remove(owner))
+                throw new IllegalArgumentException("Session '" + session + "' not registered with owner '" + owner + "'");
+
+            if (owners.isEmpty()) {
+                if (broadcast)
+                    net.unregisterSession(session);
+                return null;
+            }
+            return owners;
+        });
+    }
+
+    @Override
+    public Protocol getProtocol(Utf8Array name) {
+        // Should ideally couple this to the actual receiver ...
+        Protocol protocol = null;
+        for (NetworkOwner owner : owners)
+            protocol = owner.getProtocol(name) == null ? protocol : owner.getProtocol(name);
+
+        return protocol;
+    }
+
+    @Override
+    public void deliverMessage(Message message, String session) {
+        // Send to first owner which has registered this session, or fall back to first attached owner (for rejection).
+        NetworkOwner owner = sessions.getOrDefault(session, owners).peek();
+        if (owner == null) { // Should not happen.
+            log.warning(this + " received message '" + message + "' with no owners attached");
+            message.discard();
+        }
+        else
+            owner.deliverMessage(message, session);
+    }
+
+    public void attach(NetworkOwner owner) {
+        if (owners.contains(owner))
+            throw new IllegalArgumentException(owner + " is already attached to this");
+
+        owners.add(owner);
+    }
+
+    public void detach(NetworkOwner owner) {
+        if ( ! owners.remove(owner))
+            throw new IllegalArgumentException(owner + " not attached to this");
+
+        if ( ! shared && owners.isEmpty())
+            net.shutdown();
+    }
+
+    public void destroy() {
+        if ( ! shared)
+            throw new UnsupportedOperationException("Destroy called on a dedicated multiplexer; " +
+                                                    "this automatically shuts down when detached from");
+
+        if ( ! owners.isEmpty())
+            log.warning("NetworkMultiplexer destroyed before all owners detached: " + this);
+
+        net.shutdown();
+    }
+
+    public Network net() {
+        return net;
+    }
+
+    @Override
+    public String toString() {
+        return "NetworkMultiplexer{" +
+               "net=" + net +
+               ", owners=" + owners +
+               ", sessions=" + sessions +
+               ", shared=" + shared +
+               '}';
+    }
+
+}
\ No newline at end of file
diff --git a/messagebus/src/main/java/com/yahoo/messagebus/network/NetworkOwner.java b/messagebus/src/main/java/com/yahoo/messagebus/network/NetworkOwner.java
index 2b55bf5b901..c4185d67251 100644
--- a/messagebus/src/main/java/com/yahoo/messagebus/network/NetworkOwner.java
+++ b/messagebus/src/main/java/com/yahoo/messagebus/network/NetworkOwner.java
@@ -24,7 +24,7 @@ public interface NetworkOwner {
      * @param name The name of the protocol to return.
      * @return The named protocol.
      */
-    public Protocol getProtocol(Utf8Array name);
+    Protocol getProtocol(Utf8Array name);
 
     /**
      * All messages that arrive in the network layer is passed to its owner through this function.
@@ -32,13 +32,6 @@ public interface NetworkOwner {
      * @param message The message that just arrived from the network.
      * @param session The name of the session that is the recipient of the request.
      */
-    public void deliverMessage(Message message, String session);
+    void deliverMessage(Message message, String session);
 
-    /**
-     * All replies that arrive in the network layer is passed through this to unentangle it from the network thread.
-     *
-     * @param reply   The reply that just arrived from the network.
-     * @param handler The handler that is to receive the reply.
-     */
-    public void deliverReply(Reply reply, ReplyHandler handler);
 }
diff --git a/messagebus/src/main/java/com/yahoo/messagebus/network/local/LocalNetwork.java b/messagebus/src/main/java/com/yahoo/messagebus/network/local/LocalNetwork.java
index f3c6422fbfd..06b29ed524c 100644
--- a/messagebus/src/main/java/com/yahoo/messagebus/network/local/LocalNetwork.java
+++ b/messagebus/src/main/java/com/yahoo/messagebus/network/local/LocalNetwork.java
@@ -115,7 +115,7 @@ public class LocalNetwork implements Network {
                                          error.getMessage(),
                                          error.getService() != null ? error.getService() : envelope.sender.hostId));
             }
-            owner.deliverReply(reply, envelope.parent.recipient);
+            envelope.parent.recipient.handleReply(reply);
         });
     }
 
diff --git a/messagebus/src/main/java/com/yahoo/messagebus/network/rpc/RPCNetwork.java b/messagebus/src/main/java/com/yahoo/messagebus/network/rpc/RPCNetwork.java
index 1c41f87d1ee..e95883d8dda 100644
--- a/messagebus/src/main/java/com/yahoo/messagebus/network/rpc/RPCNetwork.java
+++ b/messagebus/src/main/java/com/yahoo/messagebus/network/rpc/RPCNetwork.java
@@ -184,10 +184,8 @@ public class RPCNetwork implements Network, MethodHandler {
         }
         this.owner = owner;
 
-        RPCSendAdapter adapter1 = new RPCSendV1();
-        RPCSendAdapter adapter2 = new RPCSendV2();
-        addSendAdapter(new Version(5), adapter1);
-        addSendAdapter(new Version(6,149), adapter2);
+        sendAdapters.put(new Version(5), new RPCSendV1(this));
+        sendAdapters.put(new Version(6,149), new RPCSendV2(this));
     }
 
     @Override
@@ -327,18 +325,6 @@ public class RPCNetwork implements Network, MethodHandler {
     }
 
     /**
-     * Registers a send adapter for a given version. This will overwrite whatever is already registered under the same
-     * version.
-     *
-     * @param version the version for which to register an adapter
-     * @param adapter the adapter to register
-     */
-    private void addSendAdapter(Version version, RPCSendAdapter adapter) {
-        adapter.attach(this);
-        sendAdapters.put(version, adapter);
-    }
-
-    /**
      * Determines and returns the send adapter that is compatible with the given version. If no adapter can be found,
      * this method returns null.
      *
@@ -362,7 +348,7 @@ public class RPCNetwork implements Network, MethodHandler {
             Reply reply = new EmptyReply();
             reply.getTrace().setLevel(ctx.traceLevel);
             reply.addError(new Error(errCode, errMsg));
-            owner.deliverReply(reply, recipient);
+            recipient.handleReply(reply);
         }
     }
 
diff --git a/messagebus/src/main/java/com/yahoo/messagebus/network/rpc/RPCSend.java b/messagebus/src/main/java/com/yahoo/messagebus/network/rpc/RPCSend.java
index 1cc45eeb2d8..3c4e7627fc8 100644
--- a/messagebus/src/main/java/com/yahoo/messagebus/network/rpc/RPCSend.java
+++ b/messagebus/src/main/java/com/yahoo/messagebus/network/rpc/RPCSend.java
@@ -18,6 +18,7 @@ import com.yahoo.messagebus.ReplyHandler;
 import com.yahoo.messagebus.Routable;
 import com.yahoo.messagebus.Trace;
 import com.yahoo.messagebus.TraceLevel;
+import com.yahoo.messagebus.network.NetworkOwner;
 import com.yahoo.messagebus.routing.Hop;
 import com.yahoo.messagebus.routing.Route;
 import com.yahoo.messagebus.routing.RoutingNode;
@@ -30,9 +31,9 @@ import com.yahoo.text.Utf8Array;
  */
 public abstract class RPCSend implements MethodHandler, ReplyHandler, RequestWaiter, RPCSendAdapter {
 
-    private RPCNetwork net = null;
-    private String clientIdent = "client";
-    private String serverIdent = "server";
+    private final RPCNetwork net;
+    private final String clientIdent;
+    private final String serverIdent;
 
     protected abstract Method buildMethod();
     protected abstract String getReturnSpec();
@@ -41,13 +42,16 @@ public abstract class RPCSend implements MethodHandler, ReplyHandler, RequestWai
     protected abstract Reply createReply(Values ret, String serviceName, Trace trace);
     protected abstract Params toParams(Values req);
     protected abstract void createResponse(Values ret, Reply reply, Version version, byte [] payload);
-    @Override
-    public final void attach(RPCNetwork net) {
+
+    protected RPCSend(RPCNetwork net) {
         this.net = net;
         String prefix = net.getIdentity().getServicePrefix();
         if (prefix != null && prefix.length() > 0) {
-            clientIdent = "'" + prefix + "'";
-            serverIdent = clientIdent;
+            this.serverIdent = this.clientIdent = "'" + prefix + "'";
+        }
+        else {
+            this.clientIdent = "client";
+            this.serverIdent = "server";
         }
         net.getSupervisor().addMethod(buildMethod());
     }
@@ -76,7 +80,7 @@ public abstract class RPCSend implements MethodHandler, ReplyHandler, RequestWai
             }
             Reply reply = new EmptyReply();
             reply.getTrace().swap(ctx.trace);
-            net.getOwner().deliverReply(reply, recipient);
+            recipient.handleReply(reply);
         } else {
             req.setContext(ctx);
             address.getTarget().getJRTTarget().invokeAsync(req, ctx.timeout, this);
@@ -121,16 +125,16 @@ public abstract class RPCSend implements MethodHandler, ReplyHandler, RequestWai
             switch (req.errorCode()) {
                 case com.yahoo.jrt.ErrorCode.TIMEOUT:
                     error = new Error(ErrorCode.TIMEOUT,
-                            "A timeout occured while waiting for '" + serviceName + "' (" +
+                            "A timeout occurred while waiting for '" + serviceName + "' (" +
                                     ctx.timeout + " seconds expired); " + req.errorMessage());
                     break;
                 case com.yahoo.jrt.ErrorCode.CONNECTION:
                     error = new Error(ErrorCode.CONNECTION_ERROR,
-                            "A connection error occured for '" + serviceName + "'; " + req.errorMessage());
+                            "A connection error occurred for '" + serviceName + "'; " + req.errorMessage());
                     break;
                 default:
                     error = new Error(ErrorCode.NETWORK_ERROR,
-                            "A network error occured for '" + serviceName + "'; " + req.errorMessage());
+                            "A network error occurred for '" + serviceName + "'; " + req.errorMessage());
             }
         } else {
             reply = createReply(req.returnValues(), serviceName, ctx.trace);
@@ -143,7 +147,7 @@ public abstract class RPCSend implements MethodHandler, ReplyHandler, RequestWai
         if (error != null) {
             reply.addError(error);
         }
-        net.getOwner().deliverReply(reply, ctx.recipient);
+        ctx.recipient.handleReply(reply);
     }
 
     protected final class Params {
@@ -172,20 +176,20 @@ public abstract class RPCSend implements MethodHandler, ReplyHandler, RequestWai
         // Make sure that the owner understands the protocol.
         Protocol protocol = net.getOwner().getProtocol(p.protocolName);
         if (protocol == null) {
-            replyError(request, p.version, p.traceLevel,
+            replyError(request, p.version, protocol, p.traceLevel,
                     new Error(ErrorCode.UNKNOWN_PROTOCOL,
                             "Protocol '" + p.protocolName + "' is not known by " + serverIdent + "."));
             return;
         }
         Routable routable = protocol.decode(p.version, p.payload);
         if (routable == null) {
-            replyError(request, p.version, p.traceLevel,
+            replyError(request, p.version, protocol, p.traceLevel,
                     new Error(ErrorCode.DECODE_ERROR,
                             "Protocol '" + protocol.getName() + "' failed to decode routable."));
             return;
         }
         if (routable instanceof Reply) {
-            replyError(request, p.version, p.traceLevel,
+            replyError(request, p.version, protocol, p.traceLevel,
                     new Error(ErrorCode.DECODE_ERROR,
                             "Payload decoded to a reply when expecting a message."));
             return;
@@ -194,7 +198,7 @@ public abstract class RPCSend implements MethodHandler, ReplyHandler, RequestWai
         if (p.route != null && p.route.length() > 0) {
             msg.setRoute(net.getRoute(p.route));
         }
-        msg.setContext(new ReplyContext(request, p.version));
+        msg.setContext(new ReplyContext(request, p.version, protocol));
         msg.pushHandler(this);
         msg.setRetryEnabled(p.retryEnabled);
         msg.setRetry(p.retry);
@@ -222,13 +226,12 @@ public abstract class RPCSend implements MethodHandler, ReplyHandler, RequestWai
         // Encode and return the reply through the RPC request.
         byte[] payload = new byte[0];
         if (reply.getType() != 0) {
-            Protocol protocol = net.getOwner().getProtocol(reply.getProtocol());
-            if (protocol != null) {
-                payload = protocol.encode(ctx.version, reply);
+            if (ctx.protocol != null) {
+                payload = ctx.protocol.encode(ctx.version, reply);
             }
             if (payload == null || payload.length == 0) {
                 reply.addError(new Error(ErrorCode.ENCODE_ERROR,
-                        "An error occured while encoding the reply."));
+                        "An error occurred while encoding the reply."));
             }
         }
         createResponse(ctx.request.returnValues(), reply, ctx.version, payload);
@@ -241,11 +244,12 @@ public abstract class RPCSend implements MethodHandler, ReplyHandler, RequestWai
      * @param request    The JRT request to reply to.
      * @param version    The version to serialize for.
      * @param traceLevel The trace level to set in the reply.
+     * @param protocol   The message protocol to serialize with.
      * @param err        The error to reply with.
      */
-    private void replyError(Request request, Version version, int traceLevel, Error err) {
+    private void replyError(Request request, Version version, Protocol protocol, int traceLevel, Error err) {
         Reply reply = new EmptyReply();
-        reply.setContext(new ReplyContext(request, version));
+        reply.setContext(new ReplyContext(request, version, protocol));
         reply.getTrace().setLevel(traceLevel);
         reply.addError(err);
         handleReply(reply);
@@ -268,10 +272,12 @@ public abstract class RPCSend implements MethodHandler, ReplyHandler, RequestWai
 
         final Request request;
         final Version version;
+        final Protocol protocol;
 
-        ReplyContext(Request request, Version version) {
+        ReplyContext(Request request, Version version, Protocol protocol) {
             this.request = request;
             this.version = version;
+            this.protocol = protocol;
         }
     }
 }
diff --git a/messagebus/src/main/java/com/yahoo/messagebus/network/rpc/RPCSendAdapter.java b/messagebus/src/main/java/com/yahoo/messagebus/network/rpc/RPCSendAdapter.java
index 749ba4f4451..ea6cf59726b 100755
--- a/messagebus/src/main/java/com/yahoo/messagebus/network/rpc/RPCSendAdapter.java
+++ b/messagebus/src/main/java/com/yahoo/messagebus/network/rpc/RPCSendAdapter.java
@@ -13,13 +13,6 @@ import com.yahoo.messagebus.routing.RoutingNode;
 public interface RPCSendAdapter {
 
     /**
-     * Attaches this adapter to the given network.
-     *
-     * @param net The network to attach to.
-     */
-    void attach(RPCNetwork net);
-
-    /**
      * Performs the actual sending to the given recipient.
      *
      * @param recipient     The recipient to send to.
diff --git a/messagebus/src/main/java/com/yahoo/messagebus/network/rpc/RPCSendV1.java b/messagebus/src/main/java/com/yahoo/messagebus/network/rpc/RPCSendV1.java
index ccded0e8d1b..e6d090e3d23 100755
--- a/messagebus/src/main/java/com/yahoo/messagebus/network/rpc/RPCSendV1.java
+++ b/messagebus/src/main/java/com/yahoo/messagebus/network/rpc/RPCSendV1.java
@@ -33,8 +33,11 @@ public class RPCSendV1 extends RPCSend {
     private final String METHOD_PARAMS = "sssbilsxi";
     private final String METHOD_RETURN = "sdISSsxs";
 
+    protected RPCSendV1(RPCNetwork net) { super(net); }
+
     @Override
     protected String getReturnSpec() { return METHOD_RETURN; }
+
     @Override
     protected Method buildMethod() {
 
diff --git a/messagebus/src/main/java/com/yahoo/messagebus/network/rpc/RPCSendV2.java b/messagebus/src/main/java/com/yahoo/messagebus/network/rpc/RPCSendV2.java
index bb243651447..6ec3ea5ec7d 100644
--- a/messagebus/src/main/java/com/yahoo/messagebus/network/rpc/RPCSendV2.java
+++ b/messagebus/src/main/java/com/yahoo/messagebus/network/rpc/RPCSendV2.java
@@ -35,8 +35,11 @@ public class RPCSendV2 extends RPCSend {
     private final static String METHOD_RETURN = "bixbix";
     private final Compressor compressor = new Compressor(CompressionType.LZ4, 3, 0.90, 1024);
 
+    protected RPCSendV2(RPCNetwork net) { super(net); }
+
     @Override
     protected String getReturnSpec() { return METHOD_RETURN; }
+
     @Override
     protected Method buildMethod() {
 
diff --git a/messagebus/src/main/java/com/yahoo/messagebus/routing/RoutingNode.java b/messagebus/src/main/java/com/yahoo/messagebus/routing/RoutingNode.java
index 05fc6f62236..42d1ff9ba2d 100755
--- a/messagebus/src/main/java/com/yahoo/messagebus/routing/RoutingNode.java
+++ b/messagebus/src/main/java/com/yahoo/messagebus/routing/RoutingNode.java
@@ -805,9 +805,13 @@ public class RoutingNode implements ReplyHandler {
         this.serviceAddress = serviceAddress;
     }
 
+    /** Proxy through message bus in case it was destroyed in the meantime. */
     @Override
     public void handleReply(Reply reply) {
-        setReply(reply);
-        notifyParent();
+        mbus.deliverReply(reply, r -> {
+            setReply(reply);
+            notifyParent();
+        });
     }
+
 }
diff --git a/messagebus/src/test/java/com/yahoo/messagebus/network/NetworkMultiplexerTest.java b/messagebus/src/test/java/com/yahoo/messagebus/network/NetworkMultiplexerTest.java
new file mode 100644
index 00000000000..f1d83550601
--- /dev/null
+++ b/messagebus/src/test/java/com/yahoo/messagebus/network/NetworkMultiplexerTest.java
@@ -0,0 +1,188 @@
+// Copyright Verizon Media. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.messagebus.network;
+
+import com.yahoo.jrt.slobrok.api.IMirror;
+import com.yahoo.messagebus.Message;
+import com.yahoo.messagebus.Protocol;
+import com.yahoo.messagebus.routing.RoutingNode;
+import com.yahoo.messagebus.test.SimpleMessage;
+import com.yahoo.messagebus.test.SimpleProtocol;
+import com.yahoo.text.Utf8Array;
+import com.yahoo.text.Utf8String;
+import org.junit.Test;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.atomic.AtomicBoolean;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+/**
+ * @author jonmv
+ */
+public class NetworkMultiplexerTest {
+
+    @Test
+    public void testShared() {
+        MockNetwork net = new MockNetwork();
+        MockOwner owner1 = new MockOwner();
+        MockOwner owner2 = new MockOwner();
+        NetworkMultiplexer shared = NetworkMultiplexer.shared(net);
+        assertEquals(Set.of(shared), net.attached);
+        assertEquals(Set.of(), net.registered);
+        assertFalse(net.shutDown.get());
+
+        shared.attach(owner1);
+        shared.registerSession("s1", owner1, true);
+        try {
+            shared.registerSession("s1", owner1, true);
+            fail("Illegal to register same session multiple times with the same owner");
+        }
+        catch (IllegalArgumentException expected) {
+            assertEquals("Session 's1' with owner 'mock owner' already registered with this", expected.getMessage());
+        }
+        assertEquals(Set.of("s1"), net.registered);
+
+        shared.attach(owner2);
+        shared.registerSession("s1", owner2, true);
+        shared.registerSession("s2", owner2, true);
+        shared.registerSession("s3", owner2, false);
+        assertEquals(Set.of("s1", "s2"), net.registered);
+
+        Utf8String name = new Utf8String("protocol");
+        Protocol protocol1 = new SimpleProtocol();
+        Protocol protocol2 = new SimpleProtocol();
+        owner1.protocols.put(name, protocol1);
+        assertEquals(protocol1, shared.getProtocol(name));
+        owner2.protocols.put(name, protocol2);
+        assertEquals(protocol2, shared.getProtocol(name));
+
+        Message message1 = new SimpleMessage("one");
+        Message message2 = new SimpleMessage("two");
+        Message message3 = new SimpleMessage("three");
+        Message message4 = new SimpleMessage("four");
+        shared.deliverMessage(message1, "s1");
+        shared.deliverMessage(message2, "s2");
+        shared.unregisterSession("s1", owner1, true);
+        shared.deliverMessage(message3, "s1");
+        shared.deliverMessage(message4, "s3");
+        assertEquals(Map.of("s1", List.of(message1)), owner1.messages);
+        assertEquals(Map.of("s2", List.of(message2), "s1", List.of(message3), "s3", List.of(message4)), owner2.messages);
+
+        shared.detach(owner1);
+        assertEquals(protocol2, shared.getProtocol(name));
+
+        shared.detach(owner2);
+        assertFalse(net.shutDown.get());
+
+        shared.destroy();
+        assertTrue(net.shutDown.get());
+    }
+
+    @Test
+    public void testDedicated() {
+        MockNetwork net = new MockNetwork();
+        MockOwner owner = new MockOwner();
+        NetworkMultiplexer dedicated = NetworkMultiplexer.dedicated(net);
+        assertEquals(Set.of(dedicated), net.attached);
+        assertEquals(Set.of(), net.registered);
+        assertFalse(net.shutDown.get());
+
+        dedicated.attach(owner);
+        dedicated.detach(owner);
+        assertTrue(net.shutDown.get());
+    }
+
+    static class MockOwner implements NetworkOwner {
+
+        final Map<Utf8Array, Protocol> protocols = new HashMap<>();
+        final Map<String, List<Message>> messages = new HashMap<>();
+
+        @Override
+        public Protocol getProtocol(Utf8Array name) {
+            return protocols.get(name);
+        }
+
+        @Override
+        public void deliverMessage(Message message, String session) {
+            messages.computeIfAbsent(session, __ -> new ArrayList<>()).add(message);
+        }
+
+        @Override
+        public String toString() {
+            return "mock owner";
+        }
+
+    }
+
+    static class MockNetwork implements Network {
+
+        final Set<NetworkOwner> attached = new HashSet<>();
+        final Set<String> registered = new HashSet<>();
+        final AtomicBoolean shutDown = new AtomicBoolean();
+
+        @Override
+        public boolean waitUntilReady(double seconds) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public void attach(NetworkOwner owner) {
+            assertTrue(attached.add(owner));
+        }
+
+        @Override
+        public void registerSession(String session) {
+            assertTrue(registered.add(session));
+        }
+
+        @Override
+        public void unregisterSession(String session) {
+            assertTrue(registered.remove(session));
+        }
+
+        @Override
+        public boolean allocServiceAddress(RoutingNode recipient) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public void freeServiceAddress(RoutingNode recipient) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public void send(Message msg, List<RoutingNode> recipients) {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public void sync() {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public void shutdown() {
+            assertFalse(shutDown.getAndSet(true));
+        }
+
+        @Override
+        public String getConnectionSpec() {
+            throw new UnsupportedOperationException();
+        }
+
+        @Override
+        public IMirror getMirror() {
+            throw new UnsupportedOperationException();
+        }
+
+    }
+
+}