Improve logging of FleetController and DatabaseHandler

20 files changed, 370 insertions, 255 deletions

diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/Context.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/Context.java
new file mode 100644
index 00000000000..fbe252f3331
--- /dev/null
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/Context.java
@@ -0,0 +1,19 @@
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.clustercontroller.core;
+
+import java.util.function.Supplier;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/**
+ * Context for FleetController and all instances 1:1 with the FleetController.
+ *
+ * @author hakon
+ */
+public interface Context {
+    FleetControllerId id();
+
+    default void log(Logger logger, Level level, String message) { log(logger, level, () -> message); }
+    void log(Logger logger, Level level, String message, Throwable t);
+    void log(Logger logger, Level level, Supplier<String> message);
+}
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ContextImpl.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ContextImpl.java
new file mode 100644
index 00000000000..7dbb3ef9c67
--- /dev/null
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ContextImpl.java
@@ -0,0 +1,36 @@
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.clustercontroller.core;
+
+import java.util.function.Supplier;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/**
+ * @author hakon
+ */
+public class ContextImpl implements Context {
+    private final FleetControllerId id;
+
+    public ContextImpl(FleetControllerOptions options) {
+        this(FleetControllerId.fromOptions(options));
+    }
+
+    public ContextImpl(FleetControllerId id) {
+        this.id = id;
+    }
+
+    @Override
+    public FleetControllerId id() { return id; }
+
+    @Override
+    public void log(Logger logger, Level level, String message, Throwable t) {
+        logger.log(level, withLogPrefix(message), t);
+    }
+
+    @Override
+    public void log(Logger logger, Level level, Supplier<String> message) {
+        logger.log(level, () -> withLogPrefix(message.get()));
+    }
+
+    protected String withLogPrefix(String message) { return "Cluster '" + id.clusterName() + "': " + message; }
+}
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/FleetController.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/FleetController.java
index 20b62576ff5..f59b4111f37 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/FleetController.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/FleetController.java
@@ -50,8 +50,9 @@ import java.util.stream.Stream;
 public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAddedOrRemovedListener, SystemStateListener,
                                         Runnable, RemoteClusterControllerTaskScheduler {
 
-    private static final Logger log = Logger.getLogger(FleetController.class.getName());
+    private static final Logger logger = Logger.getLogger(FleetController.class.getName());
 
+    private final Context context;
     private final Timer timer;
     private final Object monitor;
     private final EventLog eventLog;
@@ -70,7 +71,6 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
     private final AtomicBoolean running = new AtomicBoolean(true);
     private FleetControllerOptions options;
     private FleetControllerOptions nextOptions;
-    private final int configuredIndex;
     private final List<SystemStateListener> systemStateListeners = new CopyOnWriteArrayList<>();
     private boolean processingCycle = false;
     private boolean wantedStateChanged = false;
@@ -83,8 +83,6 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
     private final StatusPageServer.PatternRequestRouter statusRequestRouter = new StatusPageServer.PatternRequestRouter();
     private final List<ClusterStateBundle> newStates = new ArrayList<>();
     private final List<ClusterStateBundle> convergedStates = new ArrayList<>();
-    private long configGeneration = -1;
-    private long nextConfigGeneration = -1;
     private final Queue<RemoteClusterControllerTask> remoteTasks = new LinkedList<>();
     private final MetricUpdater metricUpdater;
 
@@ -107,12 +105,13 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
         @Override
         public FleetControllerOptions getOptions() { return options; }
         @Override
-        public long getConfigGeneration() { return configGeneration; }
+        public long getConfigGeneration() { return 0; }
         @Override
         public ContentCluster getCluster() { return cluster; }
     };
 
-    public FleetController(Timer timer,
+    public FleetController(Context context,
+                           Timer timer,
                            EventLog eventLog,
                            ContentCluster cluster,
                            NodeStateGatherer nodeStateGatherer,
@@ -126,8 +125,8 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
                            MasterElectionHandler masterElectionHandler,
                            MetricUpdater metricUpdater,
                            FleetControllerOptions options) {
-        log.info("Starting up cluster controller " + options.fleetControllerIndex + " for cluster " + cluster.getName());
-        this.configuredIndex = options.fleetControllerIndex;
+        context.log(logger, Level.INFO, "Created");
+        this.context = context;
         this.timer = timer;
         this.monitor = timer;
         this.eventLog = eventLog;
@@ -169,15 +168,16 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
     public static FleetController create(FleetControllerOptions options,
                                          StatusPageServerInterface statusPageServer,
                                          MetricReporter metricReporter) throws Exception {
-        Timer timer = new RealTimer();
-        MetricUpdater metricUpdater = new MetricUpdater(metricReporter, options.fleetControllerIndex, options.clusterName);
-        EventLog log = new EventLog(timer, metricUpdater);
-        ContentCluster cluster = new ContentCluster(
+        var context = new ContextImpl(options);
+        var timer = new RealTimer();
+        var metricUpdater = new MetricUpdater(metricReporter, options.fleetControllerIndex, options.clusterName);
+        var log = new EventLog(timer, metricUpdater);
+        var cluster = new ContentCluster(
                 options.clusterName,
                 options.nodes,
                 options.storageDistribution);
-        NodeStateGatherer stateGatherer = new NodeStateGatherer(timer, timer, log);
-        Communicator communicator = new RPCCommunicator(
+        var stateGatherer = new NodeStateGatherer(timer, timer, log);
+        var communicator = new RPCCommunicator(
                 RPCCommunicator.createRealSupervisor(),
                 timer,
                 options.fleetControllerIndex,
@@ -185,13 +185,14 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
                 options.nodeStateRequestTimeoutEarliestPercentage,
                 options.nodeStateRequestTimeoutLatestPercentage,
                 options.nodeStateRequestRoundTripTimeMaxSeconds);
-        DatabaseHandler database = new DatabaseHandler(new ZooKeeperDatabaseFactory(), timer, options.zooKeeperServerAddress, options.fleetControllerIndex, timer);
-        NodeLookup lookUp = new SlobrokClient(timer);
-        StateChangeHandler stateGenerator = new StateChangeHandler(timer, log);
-        SystemStateBroadcaster stateBroadcaster = new SystemStateBroadcaster(timer, timer);
-        MasterElectionHandler masterElectionHandler = new MasterElectionHandler(options.fleetControllerIndex, options.fleetControllerCount, timer, timer);
-        FleetController controller = new FleetController(
-                timer, log, cluster, stateGatherer, communicator, statusPageServer, null, lookUp, database, stateGenerator, stateBroadcaster, masterElectionHandler, metricUpdater, options);
+        var database = new DatabaseHandler(context, new ZooKeeperDatabaseFactory(), timer, options.zooKeeperServerAddress, timer);
+        var lookUp = new SlobrokClient(timer);
+        var stateGenerator = new StateChangeHandler(timer, log);
+        var stateBroadcaster = new SystemStateBroadcaster(timer, timer);
+        var masterElectionHandler = new MasterElectionHandler(context, options.fleetControllerIndex, options.fleetControllerCount, timer, timer);
+        var controller = new FleetController(context, timer, log, cluster, stateGatherer, communicator,
+                                             statusPageServer, null, lookUp, database, stateGenerator,
+                                             stateBroadcaster, masterElectionHandler, metricUpdater, options);
         controller.start();
         return controller;
     }
@@ -227,7 +228,7 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
 
     public void schedule(RemoteClusterControllerTask task) {
         synchronized (monitor) {
-            log.fine("Scheduled remote task " + task.getClass().getName() + " for execution");
+            context.log(logger, Level.FINE, "Scheduled remote task " + task.getClass().getName() + " for execution");
             remoteTasks.add(task);
         }
     }
@@ -280,12 +281,12 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
 
     public void shutdown() throws InterruptedException, java.io.IOException {
         if (runner != null && isRunning()) {
-            log.log(Level.INFO,  "Joining event thread.");
+            context.log(logger, Level.INFO, "Joining event thread.");
             running.set(false);
             synchronized(monitor) { monitor.notifyAll(); }
             runner.join();
         }
-        log.log(Level.INFO,  "Fleetcontroller done shutting down event thread.");
+        context.log(logger, Level.INFO, "FleetController done shutting down event thread.");
         controllerThreadId = Thread.currentThread().getId();
         database.shutdown(databaseContext);
 
@@ -299,12 +300,12 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
         nodeLookup.shutdown();
     }
 
-    public void updateOptions(FleetControllerOptions options, long configGeneration) {
+    public void updateOptions(FleetControllerOptions options) {
+        var newId = FleetControllerId.fromOptions(options);
         synchronized(monitor) {
-            assert(this.options.fleetControllerIndex == options.fleetControllerIndex);
-            log.log(Level.INFO, "Fleetcontroller " + options.fleetControllerIndex + " has new options");
+            assert newId.equals(context.id());
+            context.log(logger, Level.INFO, "FleetController has new options");
             nextOptions = options.clone();
-            nextConfigGeneration = configGeneration;
             monitor.notifyAll();
         }
     }
@@ -348,8 +349,8 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
         var previouslyExhausted = calc.enumerateNodeResourceExhaustions(nodeInfo);
         var nowExhausted        = calc.resourceExhaustionsFromHostInfo(nodeInfo, newHostInfo);
         if (!previouslyExhausted.equals(nowExhausted)) {
-            log.fine(() -> String.format("Triggering state recomputation due to change in cluster feed block: %s -> %s",
-                                         previouslyExhausted, nowExhausted));
+            context.log(logger, Level.FINE, () -> String.format("Triggering state recomputation due to change in cluster feed block: %s -> %s",
+                                            previouslyExhausted, nowExhausted));
             stateChangeHandler.setStateChangedFlag();
         }
     }
@@ -421,7 +422,7 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
 
     /**
      * This function gives data of the current state in master election.
-     * The keys in the given map are indexes of fleet controllers.
+     * The keys in the given map are indices of fleet controllers.
      * The values are what fleetcontroller that fleetcontroller wants to
      * become master.
      *
@@ -431,7 +432,7 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
      */
     public void handleFleetData(Map<Integer, Integer> data) {
         verifyInControllerThread();
-        log.log(Level.FINEST, "Sending fleet data event on to master election handler");
+        context.log(logger, Level.FINEST, "Sending fleet data event on to master election handler");
         metricUpdater.updateMasterElectionMetrics(data);
         masterElectionHandler.handleFleetData(data);
     }
@@ -466,12 +467,12 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
     }
 
     /** Called when all distributors have acked newest cluster state version. */
-    public void handleAllDistributorsInSync(DatabaseHandler database, DatabaseHandler.Context context) throws InterruptedException {
+    public void handleAllDistributorsInSync(DatabaseHandler database, DatabaseHandler.DatabaseContext dbContext) throws InterruptedException {
         Set<ConfiguredNode> nodes = new HashSet<>(cluster.clusterInfo().getConfiguredNodes().values());
         // TODO wouldn't it be better to always get bundle information from the state broadcaster?
         var currentBundle = stateVersionTracker.getVersionedClusterStateBundle();
-        log.fine(() -> String.format("All distributors have ACKed cluster state version %d", currentBundle.getVersion()));
-        stateChangeHandler.handleAllDistributorsInSync(currentBundle.getBaselineClusterState(), nodes, database, context);
+        context.log(logger, Level.FINE, () -> String.format("All distributors have ACKed cluster state version %d", currentBundle.getVersion()));
+        stateChangeHandler.handleAllDistributorsInSync(currentBundle.getBaselineClusterState(), nodes, database, dbContext);
         convergedStates.add(currentBundle);
     }
 
@@ -531,9 +532,9 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
             try{
                 rpcServer.setSlobrokConnectionSpecs(options.slobrokConnectionSpecs, options.rpcPort);
             } catch (ListenFailedException e) {
-                log.log(Level.WARNING, "Failed to bind RPC server to port " + options.rpcPort +". This may be natural if cluster has altered the services running on this node: " + e.getMessage());
+                context.log(logger, Level.WARNING, "Failed to bind RPC server to port " + options.rpcPort + ". This may be natural if cluster has altered the services running on this node: " + e.getMessage());
             } catch (Exception e) {
-                log.log(Level.WARNING, "Failed to initialize RPC server socket: " + e.getMessage());
+                context.log(logger, Level.WARNING, "Failed to initialize RPC server socket: " + e.getMessage());
             }
         }
 
@@ -541,21 +542,19 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
             try{
                 statusPageServer.setPort(options.httpPort);
             } catch (Exception e) {
-                log.log(Level.WARNING, "Failed to initialize status server socket. This may be natural if cluster has altered the services running on this node: " + e.getMessage());
+                context.log(logger, Level.WARNING, "Failed to initialize status server socket. This may be natural if cluster has altered the services running on this node: " + e.getMessage());
             }
         }
 
         long currentTime = timer.getCurrentTimeInMillis();
         nextStateSendTime = Math.min(currentTime + options.minTimeBetweenNewSystemStates, nextStateSendTime);
-        configGeneration = nextConfigGeneration;
-        nextConfigGeneration = -1;
     }
 
     private void selfTerminateIfConfiguredNodeIndexHasChanged() {
-        if (options.fleetControllerIndex != configuredIndex) {
-            log.warning(String.format("Got new configuration where CC index has changed from %d to %d. We do not support "+
-                                      "doing this live; immediately exiting now to force new configuration",
-                                      configuredIndex, options.fleetControllerIndex));
+        var newId = new FleetControllerId(options.clusterName, options.fleetControllerIndex);
+        if (!newId.equals(context.id())) {
+            context.log(logger, Level.WARNING, context.id() + " got new configuration for " + newId + ". We do not support doing this live; " +
+                               "immediately exiting now to force new configuration");
             prepareShutdownEdge();
             System.exit(1);
         }
@@ -565,7 +564,7 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
         verifyInControllerThread();
         StatusPageResponse.ResponseCode responseCode;
         String message;
-        String hiddenMessage = "";
+        final String hiddenMessage;
         try {
             StatusPageServer.RequestHandler handler = statusRequestRouter.resolveHandler(httpRequest);
             if (handler == null) {
@@ -575,12 +574,12 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
         } catch (FileNotFoundException e) {
             responseCode = StatusPageResponse.ResponseCode.NOT_FOUND;
             message = e.getMessage();
+            hiddenMessage = "";
         } catch (Exception e) {
             responseCode = StatusPageResponse.ResponseCode.INTERNAL_SERVER_ERROR;
             message = "Internal Server Error";
             hiddenMessage = ExceptionUtils.getStackTraceAsString(e);
-            if (log.isLoggable(Level.FINE))
-                log.log(Level.FINE, "Unknown exception thrown for request " + httpRequest.getRequest() + ": " + hiddenMessage);
+            context.log(logger, Level.FINE, () -> "Unknown exception thrown for request " + httpRequest.getRequest() + ": " + hiddenMessage);
         }
 
         TimeZone tz = TimeZone.getTimeZone("UTC");
@@ -664,7 +663,7 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
         } catch (InterruptedException e) {
             throw new RuntimeException(e);
         } catch (Exception e) {
-            log.log(Level.WARNING, "Failed to watch master election: " + e.toString());
+            context.log(logger, Level.WARNING, "Failed to watch master election: " + e);
         }
         return false;
     }
@@ -683,7 +682,7 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
         try {
             propagateOptions();
         } catch (Exception e) {
-            log.log(Level.SEVERE, "Failed to handle new fleet controller config", e);
+            context.log(logger, Level.SEVERE, "Failed to handle new fleet controller config", e);
         }
     }
 
@@ -702,7 +701,7 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
         // If there's a pending DB store we have not yet been able to store the
         // current state bundle to ZK and must therefore _not_ allow it to be published.
         if (database.hasPendingClusterStateMetaDataStore()) {
-            log.log(Level.FINE, "Can't publish current cluster state as it has one or more pending ZooKeeper stores");
+            context.log(logger, Level.FINE, "Can't publish current cluster state as it has one or more pending ZooKeeper stores");
             return false;
         }
         boolean sentAny = false;
@@ -713,7 +712,7 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
             && currentTime >= nextStateSendTime)
         {
             if (inMasterMoratorium) {
-                log.info(currentTime < firstAllowedStateBroadcast ?
+                context.log(logger, Level.INFO, currentTime < firstAllowedStateBroadcast ?
                          "Master moratorium complete: all nodes have reported in" :
                          "Master moratorium complete: timed out waiting for all nodes to report in");
                 // Reset firstAllowedStateBroadcast to make sure all future times are after firstAllowedStateBroadcast
@@ -763,14 +762,14 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
             return false;
         }
 
-        final RemoteClusterControllerTask.Context context = createRemoteTaskProcessingContext();
-        log.finest(() -> String.format("Processing remote task of type '%s'", task.getClass().getName()));
-        task.doRemoteFleetControllerTask(context);
+        final RemoteClusterControllerTask.Context taskContext = createRemoteTaskProcessingContext();
+        context.log(logger, Level.FINEST, () -> String.format("Processing remote task of type '%s'", task.getClass().getName()));
+        task.doRemoteFleetControllerTask(taskContext);
         if (taskMayBeCompletedImmediately(task)) {
-            log.finest(() -> String.format("Done processing remote task of type '%s'", task.getClass().getName()));
+            context.log(logger, Level.FINEST, () -> String.format("Done processing remote task of type '%s'", task.getClass().getName()));
             task.notifyCompleted();
         } else {
-            log.finest(() -> String.format("Remote task of type '%s' queued until state recomputation", task.getClass().getName()));
+            context.log(logger, Level.FINEST, () -> String.format("Remote task of type '%s' queued until state recomputation", task.getClass().getName()));
             tasksPendingStateRecompute.add(task);
         }
 
@@ -849,14 +848,14 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
             VersionDependentTaskCompletion taskCompletion = taskCompletionQueue.peek();
             // TODO expose and use monotonic clock instead of system clock
             if (publishedVersion >= taskCompletion.getMinimumVersion()) {
-                log.fine(() -> String.format("Deferred task of type '%s' has minimum version %d, published is %d; completing",
-                        taskCompletion.getTask().getClass().getName(), taskCompletion.getMinimumVersion(), publishedVersion));
+                context.log(logger, Level.FINE, () -> String.format("Deferred task of type '%s' has minimum version %d, published is %d; completing",
+                                                    taskCompletion.getTask().getClass().getName(), taskCompletion.getMinimumVersion(), publishedVersion));
                 taskCompletion.getTask().notifyCompleted();
                 taskCompletionQueue.remove();
             } else if (taskCompletion.getDeadlineTimePointMs() <= now) {
                 var details = buildNodesNotYetConvergedMessage(taskCompletion.getMinimumVersion());
-                log.log(Level.WARNING, () -> String.format("Deferred task of type '%s' has exceeded wait deadline; completing with failure (details: %s)",
-                        taskCompletion.getTask().getClass().getName(), details));
+                context.log(logger, Level.WARNING, () -> String.format("Deferred task of type '%s' has exceeded wait deadline; completing with failure (details: %s)",
+                                                       taskCompletion.getTask().getClass().getName(), details));
                 taskCompletion.getTask().handleFailure(RemoteClusterControllerTask.Failure.of(
                         RemoteClusterControllerTask.FailureCondition.DEADLINE_EXCEEDED, details));
                 taskCompletion.getTask().notifyCompleted();
@@ -1007,8 +1006,8 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
         // TODO expose and use monotonic clock instead of system clock
         final long maxDeadlineTimePointMs = timer.getCurrentTimeInMillis() + options.getMaxDeferredTaskVersionWaitTime().toMillis();
         for (RemoteClusterControllerTask task : tasksPendingStateRecompute) {
-            log.finest(() -> String.format("Adding task of type '%s' to be completed at version %d",
-                    task.getClass().getName(), completeAtVersion));
+            context.log(logger, Level.FINEST, () -> String.format("Adding task of type '%s' to be completed at version %d",
+                                                  task.getClass().getName(), completeAtVersion));
             taskCompletionQueue.add(new VersionDependentTaskCompletion(completeAtVersion, task, maxDeadlineTimePointMs));
         }
         tasksPendingStateRecompute.clear();
@@ -1085,7 +1084,7 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
                 database.loadWantedStates(databaseContext);
                 // TODO determine if we need any specialized handling here if feed block is set in the loaded bundle
 
-                log.info(() -> String.format("Loaded previous cluster state bundle from ZooKeeper: %s", previousBundle));
+                context.log(logger, Level.INFO, () -> String.format("Loaded previous cluster state bundle from ZooKeeper: %s", previousBundle));
                 stateVersionTracker.setClusterStateBundleRetrievedFromZooKeeper(previousBundle);
 
                 eventLog.add(new ClusterEvent(ClusterEvent.Type.MASTER_ELECTION, "This node just became fleetcontroller master. Bumped version to "
@@ -1094,8 +1093,8 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
                 firstAllowedStateBroadcast = currentTime + options.minTimeBeforeFirstSystemStateBroadcast;
                 isMaster = true;
                 inMasterMoratorium = true;
-                log.log(Level.FINE, () -> "At time " + currentTime + " we set first system state broadcast time to be "
-                        + options.minTimeBeforeFirstSystemStateBroadcast + " ms after at time " + firstAllowedStateBroadcast + ".");
+                context.log(logger, Level.FINE, () -> "At time " + currentTime + " we set first system state broadcast time to be "
+                                      + options.minTimeBeforeFirstSystemStateBroadcast + " ms after at time " + firstAllowedStateBroadcast + ".");
                 didWork = true;
             }
             if (wantedStateChanged) {
@@ -1123,16 +1122,17 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
     @Override
     public void run() {
         controllerThreadId = Thread.currentThread().getId();
+        context.log(logger, Level.INFO, "Starting ticks");
         try {
             processingCycle = true;
             while (isRunning()) {
                 tick();
             }
         } catch (InterruptedException e) {
-            log.log(Level.FINE, () -> "Event thread stopped by interrupt exception: " + e);
+            context.log(logger, Level.FINE, () -> "Event thread stopped by interrupt exception: " + e);
         } catch (Throwable t) {
             t.printStackTrace();
-            log.log(Level.SEVERE, "Fatal error killed fleet controller", t);
+            context.log(logger, Level.SEVERE, "Fatal error killed fleet controller", t);
             synchronized (monitor) { running.set(false); }
             System.exit(1);
         } finally {
@@ -1146,7 +1146,7 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
         synchronized (monitor) { monitor.notifyAll(); }
     }
 
-    public DatabaseHandler.Context databaseContext = new DatabaseHandler.Context() {
+    public DatabaseHandler.DatabaseContext databaseContext = new DatabaseHandler.DatabaseContext() {
         @Override
         public ContentCluster getCluster() { return cluster; }
         @Override
@@ -1191,7 +1191,7 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
                     }
                 }
                 if (ackedNodes >= nodeCount) {
-                    log.log(Level.INFO, ackedNodes + " nodes now have acked system state " + version + " or higher.");
+                    context.log(logger, Level.INFO, ackedNodes + " nodes now have acked system state " + version + " or higher.");
                     return;
                 }
                 long remainingTime = maxTime - System.currentTimeMillis();
@@ -1239,5 +1239,4 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
     public EventLog getEventLog() {
         return eventLog;
     }
-
 }
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/FleetControllerId.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/FleetControllerId.java
new file mode 100644
index 00000000000..fd0784d69c9
--- /dev/null
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/FleetControllerId.java
@@ -0,0 +1,44 @@
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.clustercontroller.core;
+
+import java.util.Objects;
+
+/**
+ * Uniquely identifies a running FleetController: cluster name + index.
+ *
+ * @author hakon
+ */
+public class FleetControllerId {
+    private final String clusterName;
+    private final int index;
+
+    public static FleetControllerId fromOptions(FleetControllerOptions options) {
+        return new FleetControllerId(options.clusterName, options.fleetControllerIndex);
+    }
+
+    public FleetControllerId(String clusterName, int index) {
+        this.clusterName = clusterName;
+        this.index = index;
+    }
+
+    public String clusterName() { return clusterName; }
+    public int index() { return index; }
+
+    @Override
+    public String toString() {
+        return "FleetController " + index + " for cluster '" + clusterName + '\'';
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        FleetControllerId that = (FleetControllerId) o;
+        return index == that.index && Objects.equals(clusterName, that.clusterName);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(clusterName, index);
+    }
+}
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/MasterElectionHandler.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/MasterElectionHandler.java
index 9ae3d543121..4c2187eca4d 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/MasterElectionHandler.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/MasterElectionHandler.java
@@ -12,8 +12,9 @@ import java.util.logging.Logger;
  */
 public class MasterElectionHandler implements MasterInterface {
 
-    private static final Logger log = Logger.getLogger(MasterElectionHandler.class.getName());
+    private static final Logger logger = Logger.getLogger(MasterElectionHandler.class.getName());
 
+    private final Context context;
     private final Object monitor;
     private final Timer timer;
     private final int index;
@@ -27,7 +28,8 @@ public class MasterElectionHandler implements MasterInterface {
     private long masterZooKeeperCooldownPeriod; // The period in ms that we won't take over unless master come back.
     private boolean usingZooKeeper = false; // Unit tests may not use ZooKeeper at all.
 
-    public MasterElectionHandler(int index, int totalCount, Object monitor, Timer timer) {
+    public MasterElectionHandler(Context context, int index, int totalCount, Object monitor, Timer timer) {
+        this.context = context;
         this.monitor = monitor;
         this.timer = timer;
         this.index = index;
@@ -35,7 +37,7 @@ public class MasterElectionHandler implements MasterInterface {
         this.nextInLineCount = Integer.MAX_VALUE;
         // Only a given set of nodes can ever become master
         if (index > (totalCount - 1) / 2) {
-            log.log(Level.FINE, () -> "Cluster controller " + index + ": We can never become master and will always stay a follower.");
+            context.log(logger, Level.FINE, () -> "We can never become master and will always stay a follower.");
         }
             // Tag current time as when we have not seen any other master. Make sure we're not taking over at once for master that is on the way down
         masterGoneFromZooKeeperTime = timer.getCurrentTimeInMillis();
@@ -119,38 +121,38 @@ public class MasterElectionHandler implements MasterInterface {
     public boolean isAmongNthFirst(int first) { return (nextInLineCount < first); }
 
     public boolean watchMasterElection(DatabaseHandler database,
-                                       DatabaseHandler.Context dbContext) throws InterruptedException {
+                                       DatabaseHandler.DatabaseContext dbContext) throws InterruptedException {
         if (totalCount == 1 && !usingZooKeeper) {
             return false; // Allow single configured node to become master implicitly if no ZK configured
         }
         if (nextMasterData == null) {
             if (masterCandidate == null) {
-                log.log(Level.FINEST, () -> "Cluster controller " + index + ": No current master candidate. Waiting for data to do master election.");
+                context.log(logger, Level.FINEST, () -> "No current master candidate. Waiting for data to do master election.");
             }
             return false; // Nothing have happened since last time.
         }
             // Move next data to temporary, such that we don't need to keep lock, and such that we don't retry
             // if we happen to fail processing the data.
         Map<Integer, Integer> state;
-        log.log(Level.INFO, "Cluster controller " + index + ": Handling new master election, as we have received " + nextMasterData.size() + " entries");
+        context.log(logger, Level.INFO, "Handling new master election, as we have received " + nextMasterData.size() + " entries");
         synchronized (monitor) {
             state = nextMasterData;
             nextMasterData = null;
         }
-        log.log(Level.INFO, "Cluster controller " + index + ": Got master election state " + toString(state) + ".");
+        context.log(logger, Level.INFO, "Got master election state " + toString(state) + ".");
         if (state.isEmpty()) throw new IllegalStateException("Database has no master data. We should at least have data for ourselves.");
         Map.Entry<Integer, Integer> first = state.entrySet().iterator().next();
         Integer currentMaster = getMaster();
         if (currentMaster != null && first.getKey().intValue() != currentMaster.intValue()) {
-            log.log(Level.INFO, "Cluster controller " + index + ": Master gone from ZooKeeper. Tagging timestamp. Will wait " + this.masterZooKeeperCooldownPeriod + " ms.");
+            context.log(logger, Level.INFO, "Master gone from ZooKeeper. Tagging timestamp. Will wait " + this.masterZooKeeperCooldownPeriod + " ms.");
             masterGoneFromZooKeeperTime = timer.getCurrentTimeInMillis();
             masterCandidate = null;
         }
         if (first.getValue().intValue() != first.getKey().intValue()) {
-            log.log(Level.INFO, "Fleet controller " + index + ": First index is not currently trying to become master. Waiting for it to change state");
+            context.log(logger, Level.INFO, "First index is not currently trying to become master. Waiting for it to change state");
             masterCandidate = null;
             if (first.getKey() == index) {
-                log.log(Level.INFO, "Cluster controller " + index + ": We are next in line to become master. Altering our state to look for followers");
+                context.log(logger, Level.INFO, "We are next in line to become master. Altering our state to look for followers");
                 database.setMasterVote(dbContext, index);
             }
         } else {
@@ -164,21 +166,21 @@ public class MasterElectionHandler implements MasterInterface {
             if (2 * followers > totalCount) {
                 Integer newMaster = getMaster();
                 if (newMaster != null && currentMaster != null && newMaster.intValue() == currentMaster.intValue()) {
-                    log.log(Level.INFO, "MASTER_ELECTION: Cluster controller " + index + ": " + currentMaster + " is still the master");
+                    context.log(logger, Level.INFO, currentMaster + " is still the master");
                 } else if (newMaster != null && currentMaster != null) {
-                    log.log(Level.INFO, "MASTER_ELECTION: Cluster controller " + index + ": " + newMaster + " took over for fleet controller " + currentMaster + " as master");
+                    context.log(logger, Level.INFO, newMaster + " took over for fleet controller " + currentMaster + " as master");
                 } else if (newMaster == null) {
-                    log.log(Level.INFO, "MASTER_ELECTION: Cluster controller " + index + ": " + masterCandidate + " is new master candidate, but needs to wait before it can take over");
+                    context.log(logger, Level.INFO, masterCandidate + " is new master candidate, but needs to wait before it can take over");
                 }  else {
-                    log.log(Level.INFO, "MASTER_ELECTION: Cluster controller " + index + ": " + newMaster + " is newly elected master");
+                    context.log(logger, Level.INFO, newMaster + " is newly elected master");
                 }
             } else {
-                log.log(Level.INFO, "MASTER_ELECTION: Cluster controller " + index + ": Currently too few followers for cluster controller candidate " + masterCandidate + ". No current master. (" + followers + "/" + totalCount + " followers)");
+                context.log(logger, Level.INFO, "Currently too few followers for cluster controller candidate " + masterCandidate + ". No current master. (" + followers + "/" + totalCount + " followers)");
             }
             Integer ourState = state.get(index);
             if (ourState == null) throw new IllegalStateException("Database lacks data from ourselves. This should always be present.");
             if (ourState.intValue() != first.getKey().intValue()) {
-                log.log(Level.INFO, "Cluster controller " + index + ": Altering our state to follow new fleet controller master candidate " + first.getKey());
+                context.log(logger, Level.INFO, "Altering our state to follow new fleet controller master candidate " + first.getKey());
                 database.setMasterVote(dbContext, first.getKey());
             }
         }
@@ -195,7 +197,7 @@ public class MasterElectionHandler implements MasterInterface {
             if (nextInLineCount != ourPosition) {
                 nextInLineCount = ourPosition;
                 if (ourPosition > 0) {
-                    log.log(Level.FINE, () -> "Cluster controller " + index + ": We are now " + getPosition(nextInLineCount) + " in queue to take over being master.");
+                    context.log(logger, Level.FINE, () -> "We are now " + getPosition(nextInLineCount) + " in queue to take over being master.");
                 }
             }
         }
@@ -225,7 +227,7 @@ public class MasterElectionHandler implements MasterInterface {
     }
 
     public void handleFleetData(Map<Integer, Integer> data) {
-        log.log(Level.INFO, "Cluster controller " + index + ": Got new fleet data with " + data.size() + " entries: " + data);
+        context.log(logger, Level.INFO, "Got new fleet data with " + data.size() + " entries: " + data);
         synchronized (monitor) {
             nextMasterData = data;
             monitor.notifyAll();
@@ -234,7 +236,7 @@ public class MasterElectionHandler implements MasterInterface {
 
     public void lostDatabaseConnection() {
         if (totalCount > 1 || usingZooKeeper) {
-            log.log(Level.INFO, "Cluster controller " + index + ": Clearing master data as we lost connection on node " + index);
+            context.log(logger, Level.INFO, "Clearing master data as we lost connection on node " + index);
             resetElectionProgress();
         }
     }
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/StateChangeHandler.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/StateChangeHandler.java
index 4a57be7ddf1..5035ed1aa88 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/StateChangeHandler.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/StateChangeHandler.java
@@ -50,7 +50,7 @@ public class StateChangeHandler {
     public void handleAllDistributorsInSync(final ClusterState currentState,
                                             final Set<ConfiguredNode> nodes,
                                             final DatabaseHandler database,
-                                            final DatabaseHandler.Context dbContext) throws InterruptedException {
+                                            final DatabaseHandler.DatabaseContext dbContext) throws InterruptedException {
         int startTimestampsReset = 0;
         log.log(Level.FINE, "handleAllDistributorsInSync invoked for state version %d", currentState.getVersion());
         for (NodeType nodeType : NodeType.getTypes()) {
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/SystemStateBroadcaster.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/SystemStateBroadcaster.java
index 9a0ac182017..bc8d84c4634 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/SystemStateBroadcaster.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/SystemStateBroadcaster.java
@@ -178,7 +178,7 @@ public class SystemStateBroadcaster {
         return nodeIsReachable(node);
     }
 
-    private List<NodeInfo> resolveStateVersionSendSet(DatabaseHandler.Context dbContext) {
+    private List<NodeInfo> resolveStateVersionSendSet(DatabaseHandler.DatabaseContext dbContext) {
         return dbContext.getCluster().getNodeInfo().stream()
                 .filter(this::nodeNeedsClusterStateBundle)
                 .filter(node -> !newestStateBundleAlreadySentToNode(node))
@@ -186,7 +186,7 @@ public class SystemStateBroadcaster {
     }
 
     // Precondition: no nodes in the cluster need to receive the current cluster state version bundle
-    private List<NodeInfo> resolveStateActivationSendSet(DatabaseHandler.Context dbContext) {
+    private List<NodeInfo> resolveStateActivationSendSet(DatabaseHandler.DatabaseContext dbContext) {
         return dbContext.getCluster().getNodeInfo().stream()
                 .filter(this::nodeNeedsClusterStateActivation)
                 .filter(node -> !newestStateActivationAlreadySentToNode(node))
@@ -207,7 +207,7 @@ public class SystemStateBroadcaster {
      * object and updates the broadcaster's last known in-sync cluster state version.
      */
     void checkIfClusterStateIsAckedByAllDistributors(DatabaseHandler database,
-                                                     DatabaseHandler.Context dbContext,
+                                                     DatabaseHandler.DatabaseContext dbContext,
                                                      FleetController fleetController) throws InterruptedException {
         if ((clusterStateBundle == null) || currentClusterStateIsConverged()) {
             return; // Nothing to do for the current state
@@ -248,7 +248,7 @@ public class SystemStateBroadcaster {
         lastStateVersionBundleAcked = clusterStateBundle.getVersion();
     }
 
-    private void markCurrentClusterStateAsConverged(DatabaseHandler database, DatabaseHandler.Context dbContext, FleetController fleetController) throws InterruptedException {
+    private void markCurrentClusterStateAsConverged(DatabaseHandler database, DatabaseHandler.DatabaseContext dbContext, FleetController fleetController) throws InterruptedException {
         log.log(Level.FINE, "All distributors have newest clusterstate, updating start timestamps in zookeeper and clearing them from cluster state");
         lastClusterStateVersionConverged = clusterStateBundle.getVersion();
         lastClusterStateBundleConverged = clusterStateBundle;
@@ -267,7 +267,7 @@ public class SystemStateBroadcaster {
         lastOfficialStateVersion = clusterStateBundle.getVersion();
     }
 
-    public boolean broadcastNewStateBundleIfRequired(DatabaseHandler.Context dbContext, Communicator communicator,
+    public boolean broadcastNewStateBundleIfRequired(DatabaseHandler.DatabaseContext dbContext, Communicator communicator,
                                                      int lastClusterStateVersionWrittenToZooKeeper) {
         if (clusterStateBundle == null || clusterStateBundle.getVersion() == 0) {
             return false;
@@ -302,7 +302,7 @@ public class SystemStateBroadcaster {
         return !recipients.isEmpty();
     }
 
-    public boolean broadcastStateActivationsIfRequired(DatabaseHandler.Context dbContext, Communicator communicator) {
+    public boolean broadcastStateActivationsIfRequired(DatabaseHandler.DatabaseContext dbContext, Communicator communicator) {
         if (clusterStateBundle == null || clusterStateBundle.getVersion() == 0 || !currentBundleVersionIsTaggedOfficial()) {
             return false;
         }
@@ -331,7 +331,7 @@ public class SystemStateBroadcaster {
         return node.getStartTimestamp() != 0 && node.getWentDownWithStartTime() == node.getStartTimestamp();
     }
 
-    private static ClusterState buildModifiedClusterState(ClusterState sourceState, DatabaseHandler.Context dbContext) {
+    private static ClusterState buildModifiedClusterState(ClusterState sourceState, DatabaseHandler.DatabaseContext dbContext) {
         ClusterState newState = sourceState.clone();
         for (NodeInfo n : dbContext.getCluster().getNodeInfo()) {
             NodeState ns = newState.getNodeState(n.getNode());
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/database/DatabaseHandler.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/database/DatabaseHandler.java
index c2574f4c6cf..ad436442fd6 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/database/DatabaseHandler.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/database/DatabaseHandler.java
@@ -6,6 +6,7 @@ import com.yahoo.vdslib.state.NodeState;
 import com.yahoo.vdslib.state.State;
 import com.yahoo.vespa.clustercontroller.core.ClusterStateBundle;
 import com.yahoo.vespa.clustercontroller.core.ContentCluster;
+import com.yahoo.vespa.clustercontroller.core.Context;
 import com.yahoo.vespa.clustercontroller.core.FleetController;
 import com.yahoo.vespa.clustercontroller.core.NodeInfo;
 import com.yahoo.vespa.clustercontroller.core.Timer;
@@ -26,9 +27,9 @@ import java.util.logging.Logger;
  */
 public class DatabaseHandler {
 
-    private static final Logger log = Logger.getLogger(DatabaseHandler.class.getName());
+    private static final Logger logger = Logger.getLogger(DatabaseHandler.class.getName());
 
-    public interface Context {
+    public interface DatabaseContext {
         ContentCluster getCluster();
         FleetController getFleetController();
         NodeAddedOrRemovedListener getNodeAddedOrRemovedListener();
@@ -56,7 +57,7 @@ public class DatabaseHandler {
     }
     private class DatabaseListener implements Database.DatabaseListener {
         public void handleZooKeeperSessionDown() {
-            log.log(Level.FINE, () -> "Fleetcontroller " + nodeIndex + ": Lost contact with zookeeper server");
+            context.log(logger, Level.FINE, () -> "Lost contact with zookeeper server");
             synchronized(monitor) {
                 lostZooKeeperConnectionEvent = true;
                 monitor.notifyAll();
@@ -66,7 +67,7 @@ public class DatabaseHandler {
         public void handleMasterData(Map<Integer, Integer> data) {
             synchronized (monitor) {
                 if (masterDataEvent != null && masterDataEvent.equals(data)) {
-                    log.log(Level.FINE, () -> "Fleetcontroller " + nodeIndex + ": New master data was the same as the last one. Not responding to it");
+                    context.log(logger, Level.FINE, () -> "New master data was the same as the last one. Not responding to it");
                 } else {
                     masterDataEvent = data;
                 }
@@ -75,9 +76,9 @@ public class DatabaseHandler {
         }
     }
 
+    private final Context context;
     private final DatabaseFactory databaseFactory;
     private final Timer timer;
-    private final int nodeIndex;
     private final Object monitor;
     private String zooKeeperAddress;
     private int zooKeeperSessionTimeout = 5000;
@@ -91,15 +92,14 @@ public class DatabaseHandler {
     private long lastZooKeeperConnectionAttempt = 0;
     private int minimumWaitBetweenFailedConnectionAttempts = 10000;
     private boolean lostZooKeeperConnectionEvent = false;
-    private boolean connectionEstablishmentIsAllowed = false;
     private Map<Integer, Integer> masterDataEvent = null;
 
-    public DatabaseHandler(DatabaseFactory databaseFactory, Timer timer, String zooKeeperAddress, int ourIndex, Object monitor) throws InterruptedException
+    public DatabaseHandler(Context context, DatabaseFactory databaseFactory, Timer timer, String zooKeeperAddress, Object monitor) throws InterruptedException
     {
+        this.context = context;
         this.databaseFactory = databaseFactory;
         this.timer = timer;
-        this.nodeIndex = ourIndex;
-        pendingStore.masterVote = ourIndex; // To begin with we'll vote for ourselves.
+        pendingStore.masterVote = context.id().index(); // To begin with we'll vote for ourselves.
         this.monitor = monitor;
         // TODO: Require non-null, not possible now since at least ClusterFeedBlockTest uses null address
         this.zooKeeperAddress = zooKeeperAddress;
@@ -111,8 +111,8 @@ public class DatabaseHandler {
         }
     }
 
-    public void shutdown(Context context) {
-        relinquishDatabaseConnectivity(context);
+    public void shutdown(DatabaseContext databaseContext) {
+        relinquishDatabaseConnectivity(databaseContext);
     }
 
     public boolean isClosed() { return database == null || database.isClosed(); }
@@ -125,21 +125,21 @@ public class DatabaseHandler {
         this.minimumWaitBetweenFailedConnectionAttempts = minimumWaitBetweenFailedConnectionAttempts;
     }
 
-    public void reset(Context context) {
+    public void reset(DatabaseContext databaseContext) {
         final boolean wasRunning;
         synchronized (databaseMonitor) {
             wasRunning = database != null;
             if (wasRunning) {
-                log.log(Level.INFO, "Fleetcontroller " + nodeIndex + ": Resetting database state");
+                context.log(logger, Level.INFO, "Resetting database state");
                 database.close();
                 database = null;
             }
         }
         clearSessionMetaData(true);
-        context.getFleetController().lostDatabaseConnection();
+        databaseContext.getFleetController().lostDatabaseConnection();
 
         if (wasRunning) {
-            log.log(Level.INFO, "Fleetcontroller " + nodeIndex + ": Done resetting database state");
+            context.log(logger, Level.INFO, "Done resetting database state");
         }
     }
 
@@ -157,24 +157,24 @@ public class DatabaseHandler {
             pendingStore.clearNonClusterStateFields();
         }
         pendingStore.masterVote = currentVote;
-        log.log(Level.FINE, () -> "Cleared session metadata. Pending master vote is now " + pendingStore.masterVote);
+        context.log(logger, Level.FINE, () -> "Cleared session metadata. Pending master vote is now " + pendingStore.masterVote);
     }
 
-    public void setZooKeeperAddress(String address, Context context) {
+    public void setZooKeeperAddress(String address, DatabaseContext databaseContext) {
         if (address == null && zooKeeperAddress == null) return;
         if (address != null && address.equals(zooKeeperAddress)) return;
         if (zooKeeperAddress != null) {
-            log.log(Level.INFO, "Fleetcontroller " + nodeIndex + ": " + (address == null ? "Stopped using ZooKeeper." : "Got new ZooKeeper address to use: " + address));
+            context.log(logger, Level.INFO, "" + (address == null ? "Stopped using ZooKeeper." : "Got new ZooKeeper address to use: " + address));
         }
         zooKeeperAddress = address;
-        reset(context);
+        reset(databaseContext);
     }
 
-    public void setZooKeeperSessionTimeout(int timeout, Context context) {
+    public void setZooKeeperSessionTimeout(int timeout, DatabaseContext databaseContext) {
         if (timeout == zooKeeperSessionTimeout) return;
-        log.log(Level.FINE, () -> "Fleetcontroller " + nodeIndex + ": Got new ZooKeeper session timeout of " + timeout + " milliseconds.");
+        context.log(logger, Level.FINE, () -> "Got new ZooKeeper session timeout of " + timeout + " milliseconds.");
         zooKeeperSessionTimeout = timeout;
-        reset(context);
+        reset(databaseContext);
     }
 
     private boolean usingZooKeeper() { return (zooKeeperAddress != null); }
@@ -190,31 +190,30 @@ public class DatabaseHandler {
                 // Don't clear pending state writes in case they were attempted prior to connect()
                 // being called, but after receiving a database loss event.
                 clearSessionMetaData(false);
-                log.log(Level.INFO,
-                        "Fleetcontroller " + nodeIndex + ": Setting up new ZooKeeper session at " + zooKeeperAddress);
+                context.log(logger, Level.INFO, "Setting up new ZooKeeper session at " + zooKeeperAddress);
                 DatabaseFactory.Params params = new DatabaseFactory.Params()
                         .cluster(cluster)
-                        .nodeIndex(nodeIndex)
+                        .nodeIndex(context.id().index())
                         .databaseAddress(zooKeeperAddress)
                         .databaseSessionTimeout(zooKeeperSessionTimeout)
                         .databaseListener(dbListener);
                 database = databaseFactory.create(params);
             }
         } catch (KeeperException.NodeExistsException e) {
-            log.log(Level.FINE, () -> "Fleetcontroller " + nodeIndex + ": Cannot create ephemeral fleetcontroller node. ZooKeeper server "
-                    + "not seen old fleetcontroller instance disappear? It already exists. Will retry later: " + e.getMessage());
+            context.log(logger, Level.FINE, () -> "Cannot create ephemeral fleetcontroller node. ZooKeeper server "
+                                         + "not seen old fleetcontroller instance disappear? It already exists. Will retry later: " + e.getMessage());
         } catch (InterruptedException e) {
             throw new RuntimeException(e);
         } catch (KeeperException.ConnectionLossException e) {
-            log.log(Level.WARNING, "Fleetcontroller " + nodeIndex + ": Failed to connect to ZooKeeper at " + zooKeeperAddress
-                    + " with session timeout " + zooKeeperSessionTimeout + ": " + e.getMessage());
+            context.log(logger, Level.WARNING, "Failed to connect to ZooKeeper at " + zooKeeperAddress
+                                      + " with session timeout " + zooKeeperSessionTimeout + ": " + e.getMessage());
         } catch (Exception e) {
             StringWriter sw = new StringWriter();
             e.printStackTrace(new PrintWriter(sw));
-            log.log(Level.WARNING, "Fleetcontroller " + nodeIndex + ": Failed to connect to ZooKeeper at " + zooKeeperAddress
-                    + " with session timeout " + zooKeeperSessionTimeout + ": " + sw);
+            context.log(logger, Level.WARNING, "Failed to connect to ZooKeeper at " + zooKeeperAddress
+                                      + " with session timeout " + zooKeeperSessionTimeout + ": " + sw);
         }
-        log.log(Level.INFO, "Fleetcontroller " + nodeIndex + ": Done setting up new ZooKeeper session at " + zooKeeperAddress);
+        context.log(logger, Level.INFO, "Done setting up new ZooKeeper session at " + zooKeeperAddress);
     }
 
     /**
@@ -222,27 +221,27 @@ public class DatabaseHandler {
      *
      * @return true if we did or attempted any work.
      */
-    public boolean doNextZooKeeperTask(Context context) {
+    public boolean doNextZooKeeperTask(DatabaseContext databaseContext) {
         boolean didWork = false;
         synchronized (monitor) {
             if (lostZooKeeperConnectionEvent) {
-                log.log(Level.FINE, () -> "Fleetcontroller " + nodeIndex + ": doNextZooKeeperTask(): lost connection");
-                context.getFleetController().lostDatabaseConnection();
+                context.log(logger, Level.FINE, () -> "doNextZooKeeperTask(): lost connection");
+                databaseContext.getFleetController().lostDatabaseConnection();
                 lostZooKeeperConnectionEvent = false;
                 didWork = true;
                 if (masterDataEvent != null) {
-                    log.log(Level.FINE, () -> "Fleetcontroller " + nodeIndex + ": Had new master data queued on disconnect. Removing master data event");
+                    context.log(logger, Level.FINE, () -> "Had new master data queued on disconnect. Removing master data event");
                     masterDataEvent = null;
                 }
             }
             if (masterDataEvent != null) {
-                log.log(Level.FINE, () -> "Fleetcontroller " + nodeIndex + ": doNextZooKeeperTask(): new master data");
-                if (!masterDataEvent.containsKey(nodeIndex)) {
+                context.log(logger, Level.FINE, () -> "doNextZooKeeperTask(): new master data");
+                if (!masterDataEvent.containsKey(context.id().index())) {
                     Integer currentVote = (pendingStore.masterVote != null ? pendingStore.masterVote : currentlyStored.masterVote);
                     assert(currentVote != null);
-                    masterDataEvent.put(nodeIndex, currentVote);
+                    masterDataEvent.put(context.id().index(), currentVote);
                 }
-                context.getFleetController().handleFleetData(masterDataEvent);
+                databaseContext.getFleetController().handleFleetData(masterDataEvent);
                 masterDataEvent = null;
                 didWork = true;
             }
@@ -253,7 +252,7 @@ public class DatabaseHandler {
                 return false; // Not time to attempt connection yet.
             }
             didWork = true;
-            connect(context.getCluster(), currentTime);
+            connect(databaseContext.getCluster(), currentTime);
         }
         try {
             synchronized (databaseMonitor) {
@@ -263,11 +262,11 @@ public class DatabaseHandler {
                 didWork |= performZooKeeperWrites();
             }
         } catch (CasWriteFailed e) {
-            log.log(Level.WARNING, String.format("CaS write to ZooKeeper failed, another controller " +
-                    "has likely taken over ownership: %s", e.getMessage()));
+            context.log(logger, Level.WARNING, String.format("CaS write to ZooKeeper failed, another controller " +
+                                                    "has likely taken over ownership: %s", e.getMessage()));
             // Clear DB and master election state. This shall trigger a full re-fetch of all
             // version and election-related metadata.
-            relinquishDatabaseConnectivity(context);
+            relinquishDatabaseConnectivity(databaseContext);
         }
         return didWork;
     }
@@ -277,32 +276,31 @@ public class DatabaseHandler {
         return zooKeeperAddress != null;
     }
 
-    private void relinquishDatabaseConnectivity(Context context) {
+    private void relinquishDatabaseConnectivity(DatabaseContext databaseContext) {
         // reset() will handle both session clearing and trigger a database loss callback into the CC.
-        reset(context);
+        reset(databaseContext);
     }
 
     private boolean performZooKeeperWrites() {
         boolean didWork = false;
         if (pendingStore.masterVote != null) {
             didWork = true;
-            log.log(Level.FINE, () -> "Fleetcontroller " + nodeIndex + ": Attempting to store master vote "
-                    + pendingStore.masterVote + " into zookeeper.");
+            context.log(logger, Level.FINE, () -> "Attempting to store master vote "
+                                         + pendingStore.masterVote + " into zookeeper.");
             if (database.storeMasterVote(pendingStore.masterVote)) {
-                log.log(Level.FINE, () -> "Fleetcontroller " + nodeIndex + ": Managed to store master vote "
-                        + pendingStore.masterVote + " into zookeeper.");
+                context.log(logger, Level.FINE, () -> "Managed to store master vote "
+                                             + pendingStore.masterVote + " into zookeeper.");
                 currentlyStored.masterVote = pendingStore.masterVote;
                 pendingStore.masterVote = null;
             } else {
-                log.log(Level.WARNING, "Fleetcontroller " + nodeIndex + ": Failed to store master vote");
+                context.log(logger, Level.WARNING, "Failed to store master vote");
                 return true;
             }
         }
         if (pendingStore.lastSystemStateVersion != null) {
             didWork = true;
-            log.log(Level.FINE, () -> "Fleetcontroller " + nodeIndex
-                    + ": Attempting to store last system state version " + pendingStore.lastSystemStateVersion
-                    + " into zookeeper.");
+            context.log(logger, Level.FINE, () -> "Attempting to store last system state version " + 
+                                         pendingStore.lastSystemStateVersion + " into zookeeper.");
             if (database.storeLatestSystemStateVersion(pendingStore.lastSystemStateVersion)) {
                 currentlyStored.lastSystemStateVersion = pendingStore.lastSystemStateVersion;
                 pendingStore.lastSystemStateVersion = null;
@@ -312,8 +310,8 @@ public class DatabaseHandler {
         }
         if (pendingStore.startTimestamps != null) {
             didWork = true;
-            log.log(Level.FINE, () -> "Fleetcontroller " + nodeIndex + ": Attempting to store "
-                    + pendingStore.startTimestamps.size() + " start timestamps into zookeeper.");
+            context.log(logger, Level.FINE, () -> "Attempting to store " + pendingStore.startTimestamps.size() +
+                                         " start timestamps into zookeeper.");
             if (database.storeStartTimestamps(pendingStore.startTimestamps)) {
                 currentlyStored.startTimestamps = pendingStore.startTimestamps;
                 pendingStore.startTimestamps = null;
@@ -323,8 +321,8 @@ public class DatabaseHandler {
         }
         if (pendingStore.wantedStates != null) {
             didWork = true;
-            log.log(Level.FINE, () -> "Fleetcontroller " + nodeIndex + ": Attempting to store "
-                    + pendingStore.wantedStates.size() + " wanted states into zookeeper.");
+            context.log(logger, Level.FINE, () -> "Attempting to store "
+                                         + pendingStore.wantedStates.size() + " wanted states into zookeeper.");
             if (database.storeWantedStates(pendingStore.wantedStates)) {
                 currentlyStored.wantedStates = pendingStore.wantedStates;
                 pendingStore.wantedStates = null;
@@ -334,8 +332,8 @@ public class DatabaseHandler {
         }
         if (pendingStore.clusterStateBundle != null) {
             didWork = true;
-            log.fine(() -> String.format("Fleetcontroller %d: Attempting to store last cluster state bundle with version %d into zookeeper.",
-                                         nodeIndex, pendingStore.clusterStateBundle.getVersion()));
+            context.log(logger, Level.FINE, () -> "Attempting to store last cluster state bundle with version " + 
+                                         pendingStore.clusterStateBundle.getVersion() + " into zookeeper.");
             if (database.storeLastPublishedStateBundle(pendingStore.clusterStateBundle)) {
                 lastKnownStateBundleVersionWrittenBySelf = pendingStore.clusterStateBundle.getVersion();
                 currentlyStored.clusterStateBundle = pendingStore.clusterStateBundle;
@@ -347,8 +345,8 @@ public class DatabaseHandler {
         return didWork;
     }
 
-    public void setMasterVote(Context context, int wantedMasterCandidate) throws InterruptedException {
-        log.log(Level.FINE, () -> "Fleetcontroller " + nodeIndex + ": Checking if master vote has been updated and need to be stored.");
+    public void setMasterVote(DatabaseContext databaseContext, int wantedMasterCandidate) throws InterruptedException {
+        context.log(logger, Level.FINE, () -> "Checking if master vote has been updated and need to be stored.");
         // Schedule a write if one of the following is true:
         //   - There is already a pending vote to be written, that may have been written already without our knowledge
         //   - We don't know what is actually stored now
@@ -356,14 +354,14 @@ public class DatabaseHandler {
         if (pendingStore.masterVote != null || currentlyStored.masterVote == null
             || currentlyStored.masterVote != wantedMasterCandidate)
         {
-            log.log(Level.FINE, () -> "Fleetcontroller " + nodeIndex + ": Scheduling master vote " + wantedMasterCandidate + " to be stored in zookeeper.");
+            context.log(logger, Level.FINE, () -> "Scheduling master vote " + wantedMasterCandidate + " to be stored in zookeeper.");
             pendingStore.masterVote = wantedMasterCandidate;
-            doNextZooKeeperTask(context);
+            doNextZooKeeperTask(databaseContext);
         }
     }
 
-    public void saveLatestSystemStateVersion(Context context, int version) throws InterruptedException {
-        log.log(Level.FINE, () -> "Fleetcontroller " + nodeIndex + ": Checking if latest system state version has been updated and need to be stored.");
+    public void saveLatestSystemStateVersion(DatabaseContext databaseContext, int version) throws InterruptedException {
+        context.log(logger, Level.FINE, () -> "Checking if latest system state version has been updated and need to be stored.");
         // Schedule a write if one of the following is true:
         //   - There is already a pending vote to be written, that may have been written already without our knowledge
         //   - We don't know what is actually stored now
@@ -371,14 +369,14 @@ public class DatabaseHandler {
         if (pendingStore.lastSystemStateVersion != null || currentlyStored.lastSystemStateVersion == null
             || currentlyStored.lastSystemStateVersion != version)
         {
-            log.log(Level.FINE, () -> "Fleetcontroller " + nodeIndex + ": Scheduling new last system state version " + version + " to be stored in zookeeper.");
+            context.log(logger, Level.FINE, () -> "Scheduling new last system state version " + version + " to be stored in zookeeper.");
             pendingStore.lastSystemStateVersion = version;
-            doNextZooKeeperTask(context);
+            doNextZooKeeperTask(databaseContext);
         }
     }
 
     public int getLatestSystemStateVersion() {
-        log.log(Level.FINE, () -> "Fleetcontroller " + nodeIndex + ": Retrieving latest system state version.");
+        context.log(logger, Level.FINE, () -> "Retrieving latest system state version.");
         synchronized (databaseMonitor) {
             if (database != null && !database.isClosed()) {
                 currentlyStored.lastSystemStateVersion = database.retrieveLatestSystemStateVersion();
@@ -387,23 +385,23 @@ public class DatabaseHandler {
         Integer version = currentlyStored.lastSystemStateVersion;
         if (version == null) {
             if (usingZooKeeper()) {
-                log.log(Level.WARNING, "Fleetcontroller " + nodeIndex + ": Failed to retrieve latest system state version from ZooKeeper. Returning version 0.");
+                context.log(logger, Level.WARNING, "Failed to retrieve latest system state version from ZooKeeper. Returning version 0.");
             }
             return 0; // FIXME "fail-oblivious" is not a good error handling mode for such a critical component!
         }
         return version;
     }
 
-    public void saveLatestClusterStateBundle(Context context, ClusterStateBundle clusterStateBundle) {
-        log.log(Level.FINE, () -> String.format("Fleetcontroller %d: Scheduling bundle %s to be saved to ZooKeeper", nodeIndex, clusterStateBundle));
+    public void saveLatestClusterStateBundle(DatabaseContext databaseContext, ClusterStateBundle clusterStateBundle) {
+        context.log(logger, Level.FINE, () -> "Scheduling bundle " + clusterStateBundle + " to be saved to ZooKeeper");
         pendingStore.clusterStateBundle = clusterStateBundle;
-        doNextZooKeeperTask(context);
+        doNextZooKeeperTask(databaseContext);
         // FIXME this is a nasty hack to get around the fact that a massive amount of unit tests
         // set up the system with a null ZooKeeper server address. If we don't fake that we have
         // written the state version, the tests will never progress past waiting for state broadcasts.
         if (zooKeeperAddress == null) {
-            log.warning(() -> String.format("Fleetcontroller %d: Simulating ZK write of version %d. This should not happen in production!",
-                                             nodeIndex, clusterStateBundle.getVersion()));
+            logger.warning(() -> "Simulating ZK write of version " + clusterStateBundle.getVersion() + 
+                                 ". This should not happen in production!");
             lastKnownStateBundleVersionWrittenBySelf = clusterStateBundle.getVersion();
         }
     }
@@ -418,7 +416,7 @@ public class DatabaseHandler {
     }
 
     public ClusterStateBundle getLatestClusterStateBundle() {
-        log.log(Level.FINE, () -> String.format("Fleetcontroller %d: Retrieving latest cluster state bundle from ZooKeeper", nodeIndex));
+        context.log(logger, Level.FINE, () -> "Retrieving latest cluster state bundle from ZooKeeper");
         synchronized (databaseMonitor) {
             if (database != null && !database.isClosed()) {
                 return database.retrieveLastPublishedStateBundle();
@@ -428,10 +426,10 @@ public class DatabaseHandler {
         }
     }
 
-    public void saveWantedStates(Context context) {
-        log.log(Level.FINE, () -> "Fleetcontroller " + nodeIndex + ": Checking whether wanted states have changed compared to zookeeper version.");
+    public void saveWantedStates(DatabaseContext databaseContext) {
+        context.log(logger, Level.FINE, () -> "Checking whether wanted states have changed compared to zookeeper version.");
         Map<Node, NodeState> wantedStates = new TreeMap<>();
-        for (NodeInfo info : context.getCluster().getNodeInfo()) {
+        for (NodeInfo info : databaseContext.getCluster().getNodeInfo()) {
             if (!info.getUserWantedState().equals(new NodeState(info.getNode().getType(), State.UP))) {
                 wantedStates.put(info.getNode(), info.getUserWantedState());
             }
@@ -443,14 +441,14 @@ public class DatabaseHandler {
         if (pendingStore.wantedStates != null || currentlyStored.wantedStates == null
                 || !currentlyStored.wantedStates.equals(wantedStates))
         {
-            log.log(Level.FINE, () -> "Fleetcontroller " + nodeIndex + ": Scheduling new wanted states to be stored into zookeeper.");
+            context.log(logger, Level.FINE, () -> "Scheduling new wanted states to be stored into zookeeper.");
             pendingStore.wantedStates = wantedStates;
-            doNextZooKeeperTask(context);
+            doNextZooKeeperTask(databaseContext);
         }
     }
 
-    public boolean loadWantedStates(Context context) {
-        log.log(Level.FINE, () -> "Fleetcontroller " + nodeIndex + ": Retrieving node wanted states.");
+    public boolean loadWantedStates(DatabaseContext databaseContext) {
+        context.log(logger, Level.FINE, () -> "Retrieving node wanted states.");
         synchronized (databaseMonitor) {
             if (database != null && !database.isClosed()) {
                 currentlyStored.wantedStates = database.retrieveWantedStates();
@@ -461,43 +459,43 @@ public class DatabaseHandler {
             if (usingZooKeeper()) {
                 // We get here if the ZooKeeper client has lost the connection to ZooKeeper.
                 // TODO: Should instead fail the tick until connected!?
-                log.log(Level.FINE, () -> "Fleetcontroller " + nodeIndex + ": Failed to retrieve wanted states from ZooKeeper. Assuming UP for all nodes.");
+                context.log(logger, Level.FINE, () -> "Failed to retrieve wanted states from ZooKeeper. Assuming UP for all nodes.");
             }
             wantedStates = new TreeMap<>();
         }
         boolean altered = false;
         for (Node node : wantedStates.keySet()) {
-            NodeInfo nodeInfo = context.getCluster().getNodeInfo(node);
+            NodeInfo nodeInfo = databaseContext.getCluster().getNodeInfo(node);
             if (nodeInfo == null) continue; // ignore wanted state of nodes which doesn't exist
             NodeState wantedState = wantedStates.get(node);
             if ( ! nodeInfo.getUserWantedState().equals(wantedState)) {
                 nodeInfo.setWantedState(wantedState);
-                context.getNodeStateUpdateListener().handleNewWantedNodeState(nodeInfo, wantedState);
+                databaseContext.getNodeStateUpdateListener().handleNewWantedNodeState(nodeInfo, wantedState);
                 altered = true;
             }
-            log.log(Level.FINE, () -> "Fleetcontroller " + nodeIndex + ": Node " + node + " has wanted state " + wantedState);
+            context.log(logger, Level.FINE, () -> "Node " + node + " has wanted state " + wantedState);
         }
 
         // Remove wanted state from any node having a wanted state set that is no longer valid
-        for (NodeInfo info : context.getCluster().getNodeInfo()) {
+        for (NodeInfo info : databaseContext.getCluster().getNodeInfo()) {
             NodeState wantedState = wantedStates.get(info.getNode());
             if (wantedState == null && !info.getUserWantedState().equals(new NodeState(info.getNode().getType(), State.UP))) {
                 info.setWantedState(null);
-                context.getNodeStateUpdateListener().handleNewWantedNodeState(info, info.getWantedState().clone());
+                databaseContext.getNodeStateUpdateListener().handleNewWantedNodeState(info, info.getWantedState().clone());
                 altered = true;
             }
         }
         return altered;
     }
 
-    public void saveStartTimestamps(Context context) {
-        log.log(Level.FINE, () -> "Fleetcontroller " + nodeIndex + ": Scheduling start timestamps to be stored into zookeeper.");
-        pendingStore.startTimestamps = context.getCluster().getStartTimestamps();
-        doNextZooKeeperTask(context);
+    public void saveStartTimestamps(DatabaseContext databaseContext) {
+        context.log(logger, Level.FINE, () -> "Scheduling start timestamps to be stored into zookeeper.");
+        pendingStore.startTimestamps = databaseContext.getCluster().getStartTimestamps();
+        doNextZooKeeperTask(databaseContext);
     }
 
     public boolean loadStartTimestamps(ContentCluster cluster) {
-        log.log(Level.FINE, () -> "Fleetcontroller " + nodeIndex + ": Retrieving start timestamps");
+        context.log(logger, Level.FINE, () -> "Retrieving start timestamps");
         synchronized (databaseMonitor) {
             if (database == null || database.isClosed()) {
                 return false;
@@ -507,13 +505,13 @@ public class DatabaseHandler {
         Map<Node, Long> startTimestamps = currentlyStored.startTimestamps;
         if (startTimestamps == null) {
             if (usingZooKeeper()) {
-                log.log(Level.WARNING, "Fleetcontroller " + nodeIndex + ": Failed to retrieve start timestamps from ZooKeeper. Cluster state will be bloated with timestamps until we get them set.");
+                context.log(logger, Level.WARNING, "Failed to retrieve start timestamps from ZooKeeper. Cluster state will be bloated with timestamps until we get them set.");
             }
             startTimestamps = new TreeMap<>();
         }
         for (Map.Entry<Node, Long> e : startTimestamps.entrySet()) {
             cluster.setStartTimestamp(e.getKey(), e.getValue());
-            log.log(Level.FINE, () -> "Fleetcontroller " + nodeIndex + ": Node " + e.getKey() + " has start timestamp " + e.getValue());
+            context.log(logger, Level.FINE, () -> "Node " + e.getKey() + " has start timestamp " + e.getValue());
         }
         return true;
     }
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ClusterFeedBlockTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ClusterFeedBlockTest.java
index 308a78ee40e..80f88c57cb3 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ClusterFeedBlockTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ClusterFeedBlockTest.java
@@ -48,16 +48,17 @@ public class ClusterFeedBlockTest extends FleetControllerTest {
             nodes.add(new Node(NodeType.DISTRIBUTOR, i));
         }
 
+        var context = new TestContext(options);
         communicator = new DummyCommunicator(nodes, timer);
-        MetricUpdater metricUpdater = new MetricUpdater(new NoMetricReporter(), options.fleetControllerIndex, options.clusterName);
-        EventLog eventLog = new EventLog(timer, metricUpdater);
-        ContentCluster cluster = new ContentCluster(options.clusterName, options.nodes, options.storageDistribution);
-        NodeStateGatherer stateGatherer = new NodeStateGatherer(timer, timer, eventLog);
-        DatabaseHandler database = new DatabaseHandler(new ZooKeeperDatabaseFactory(), timer, options.zooKeeperServerAddress, options.fleetControllerIndex, timer);
-        StateChangeHandler stateGenerator = new StateChangeHandler(timer, eventLog);
-        SystemStateBroadcaster stateBroadcaster = new SystemStateBroadcaster(timer, timer);
-        MasterElectionHandler masterElectionHandler = new MasterElectionHandler(options.fleetControllerIndex, options.fleetControllerCount, timer, timer);
-        ctrl = new FleetController(timer, eventLog, cluster, stateGatherer, communicator, null, null, communicator, database, stateGenerator, stateBroadcaster, masterElectionHandler, metricUpdater, options);
+        var metricUpdater = new MetricUpdater(new NoMetricReporter(), options.fleetControllerIndex, options.clusterName);
+        var eventLog = new EventLog(timer, metricUpdater);
+        var cluster = new ContentCluster(options.clusterName, options.nodes, options.storageDistribution);
+        var stateGatherer = new NodeStateGatherer(timer, timer, eventLog);
+        var database = new DatabaseHandler(context, new ZooKeeperDatabaseFactory(), timer, options.zooKeeperServerAddress, timer);
+        var stateGenerator = new StateChangeHandler(timer, eventLog);
+        var stateBroadcaster = new SystemStateBroadcaster(timer, timer);
+        var masterElectionHandler = new MasterElectionHandler(context, options.fleetControllerIndex, options.fleetControllerCount, timer, timer);
+        ctrl = new FleetController(context, timer, eventLog, cluster, stateGatherer, communicator, null, null, communicator, database, stateGenerator, stateBroadcaster, masterElectionHandler, metricUpdater, options);
 
         ctrl.tick();
         markAllNodesAsUp(options);
@@ -134,8 +135,7 @@ public class ClusterFeedBlockTest extends FleetControllerTest {
         assertTrue(ctrl.getClusterStateBundle().clusterFeedIsBlocked());
 
         // Increase cheese allowance. Should now automatically unblock since reported usage is lower.
-        int dummyConfigGeneration = 2;
-        ctrl.updateOptions(createOptions(mapOf(usage("cheese", 0.9), usage("wine", 0.4))), dummyConfigGeneration);
+        ctrl.updateOptions(createOptions(mapOf(usage("cheese", 0.9), usage("wine", 0.4))));
         ctrl.tick(); // Options propagation
         ctrl.tick(); // State recomputation
         assertFalse(ctrl.getClusterStateBundle().clusterFeedIsBlocked());
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/DatabaseHandlerTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/DatabaseHandlerTest.java
index 630a4898dfa..57468ffa0e7 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/DatabaseHandlerTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/DatabaseHandlerTest.java
@@ -10,7 +10,6 @@ import org.junit.Test;
 
 import static org.hamcrest.Matchers.equalTo;
 import static org.junit.Assert.assertThat;
-import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyInt;
 import static org.mockito.ArgumentMatchers.eq;
@@ -41,8 +40,8 @@ public class DatabaseHandlerTest {
             when(mockTimer.getCurrentTimeInMillis()).thenReturn(1000000L);
         }
 
-        DatabaseHandler.Context createMockContext() {
-            return new DatabaseHandler.Context() {
+        DatabaseHandler.DatabaseContext createMockContext() {
+            return new DatabaseHandler.DatabaseContext() {
                 @Override
                 public ContentCluster getCluster() {
                     return clusterFixture.cluster();
@@ -66,7 +65,9 @@ public class DatabaseHandlerTest {
         }
 
         DatabaseHandler createHandler() throws Exception {
-            return new DatabaseHandler(mockDbFactory, mockTimer, databaseAddress, 0, monitor);
+            Context context = mock(Context.class);
+            when(context.id()).thenReturn(new FleetControllerId("clusterName", 0));
+            return new DatabaseHandler(context, mockDbFactory, mockTimer, databaseAddress, monitor);
         }
     }
 
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/DistributionBitCountTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/DistributionBitCountTest.java
index 0f172f6f248..e8f20a00d24 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/DistributionBitCountTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/DistributionBitCountTest.java
@@ -39,12 +39,12 @@ public class DistributionBitCountTest extends FleetControllerTest {
     public void testDistributionBitCountConfigIncrease() throws Exception {
         setUpSystem("DistributionBitCountTest::testDistributionBitCountConfigIncrease");
         options.distributionBits = 20;
-        fleetController.updateOptions(options, 0);
+        fleetController.updateOptions(options);
         ClusterState currentState = waitForState("version:\\d+ bits:20 distributor:10 storage:10");
 
         int version = currentState.getVersion();
         options.distributionBits = 23;
-        fleetController.updateOptions(options, 0);
+        fleetController.updateOptions(options);
         assertEquals(version, currentState.getVersion());
     }
 
@@ -55,7 +55,7 @@ public class DistributionBitCountTest extends FleetControllerTest {
     public void testDistributionBitCountConfigDecrease() throws Exception {
         setUpSystem("DistributionBitCountTest::testDistributionBitCountConfigDecrease");
         options.distributionBits = 12;
-        fleetController.updateOptions(options, 0);
+        fleetController.updateOptions(options);
         waitForState("version:\\d+ bits:12 distributor:10 storage:10");
     }
 
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/FleetControllerTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/FleetControllerTest.java
index 55677782a3d..d9e20171681 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/FleetControllerTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/FleetControllerTest.java
@@ -157,15 +157,16 @@ public abstract class FleetControllerTest implements Waiter {
 
     FleetController createFleetController(boolean useFakeTimer, FleetControllerOptions options, boolean startThread, StatusPageServerInterface status) throws Exception {
         Objects.requireNonNull(status, "status server cannot be null");
+        var context = new TestContext(options);
         Timer timer = useFakeTimer ? this.timer : new RealTimer();
-        MetricUpdater metricUpdater = new MetricUpdater(new NoMetricReporter(), options.fleetControllerIndex, options.clusterName);
-        EventLog log = new EventLog(timer, metricUpdater);
-        ContentCluster cluster = new ContentCluster(
+        var metricUpdater = new MetricUpdater(new NoMetricReporter(), options.fleetControllerIndex, options.clusterName);
+        var log = new EventLog(timer, metricUpdater);
+        var cluster = new ContentCluster(
                 options.clusterName,
                 options.nodes,
                 options.storageDistribution);
-        NodeStateGatherer stateGatherer = new NodeStateGatherer(timer, timer, log);
-        Communicator communicator = new RPCCommunicator(
+        var stateGatherer = new NodeStateGatherer(timer, timer, log);
+        var communicator = new RPCCommunicator(
                 RPCCommunicator.createRealSupervisor(),
                 timer,
                 options.fleetControllerIndex,
@@ -173,20 +174,20 @@ public abstract class FleetControllerTest implements Waiter {
                 options.nodeStateRequestTimeoutEarliestPercentage,
                 options.nodeStateRequestTimeoutLatestPercentage,
                 options.nodeStateRequestRoundTripTimeMaxSeconds);
-        SlobrokClient lookUp = new SlobrokClient(timer);
+        var lookUp = new SlobrokClient(timer);
         lookUp.setSlobrokConnectionSpecs(new String[0]);
-        RpcServer rpcServer = new RpcServer(timer, timer, options.clusterName, options.fleetControllerIndex, options.slobrokBackOffPolicy);
-        DatabaseHandler database = new DatabaseHandler(new ZooKeeperDatabaseFactory(), timer, options.zooKeeperServerAddress, options.fleetControllerIndex, timer);
+        var rpcServer = new RpcServer(timer, timer, options.clusterName, options.fleetControllerIndex, options.slobrokBackOffPolicy);
+        var database = new DatabaseHandler(context, new ZooKeeperDatabaseFactory(), timer, options.zooKeeperServerAddress, timer);
 
         // Setting this <1000 ms causes ECONNREFUSED on socket trying to connect to ZK server, in ZooKeeper,
         // after creating a new ZooKeeper (session).  This causes ~10s extra time to connect after connection loss.
         // Reasons unknown.  Larger values like the default 10_000 causes that much additional running time for some tests.
         database.setMinimumWaitBetweenFailedConnectionAttempts(2_000);
 
-        StateChangeHandler stateGenerator = new StateChangeHandler(timer, log);
-        SystemStateBroadcaster stateBroadcaster = new SystemStateBroadcaster(timer, timer);
-        MasterElectionHandler masterElectionHandler = new MasterElectionHandler(options.fleetControllerIndex, options.fleetControllerCount, timer, timer);
-        FleetController controller = new FleetController(timer, log, cluster, stateGatherer, communicator, status, rpcServer, lookUp, database, stateGenerator, stateBroadcaster, masterElectionHandler, metricUpdater, options);
+        var stateGenerator = new StateChangeHandler(timer, log);
+        var stateBroadcaster = new SystemStateBroadcaster(timer, timer);
+        var masterElectionHandler = new MasterElectionHandler(context, options.fleetControllerIndex, options.fleetControllerCount, timer, timer);
+        var controller = new FleetController(context, timer, log, cluster, stateGatherer, communicator, status, rpcServer, lookUp, database, stateGenerator, stateBroadcaster, masterElectionHandler, metricUpdater, options);
         if (startThread) {
             controller.start();
         }
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/GroupAutoTakedownLiveConfigTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/GroupAutoTakedownLiveConfigTest.java
index 77bcff1e7d5..e6c5c31010f 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/GroupAutoTakedownLiveConfigTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/GroupAutoTakedownLiveConfigTest.java
@@ -9,8 +9,6 @@ import static org.junit.Assert.assertFalse;
 
 public class GroupAutoTakedownLiveConfigTest extends FleetControllerTest {
 
-    private long mockConfigGeneration = 1;
-
     private static FleetControllerOptions createOptions(DistributionBuilder.GroupBuilder groupBuilder, double minNodeRatio) {
         FleetControllerOptions options = defaultOptions("mycluster");
         options.setStorageDistribution(DistributionBuilder.forHierarchicCluster(groupBuilder));
@@ -21,8 +19,7 @@ public class GroupAutoTakedownLiveConfigTest extends FleetControllerTest {
     }
 
     private void updateConfigLive(FleetControllerOptions newOptions) {
-        ++mockConfigGeneration;
-        this.fleetController.updateOptions(newOptions, mockConfigGeneration);
+        this.fleetController.updateOptions(newOptions);
     }
 
     private void reconfigureWithMinNodeRatio(double minNodeRatio) {
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/GroupAutoTakedownTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/GroupAutoTakedownTest.java
index 83167367a91..a3bc39bde39 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/GroupAutoTakedownTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/GroupAutoTakedownTest.java
@@ -307,7 +307,7 @@ public class GroupAutoTakedownTest {
         assertEquals("distributor:6 storage:6 .4.t:123456", fixture.generatedClusterState());
 
         DatabaseHandler handler = mock(DatabaseHandler.class);
-        DatabaseHandler.Context context = mock(DatabaseHandler.Context.class);
+        DatabaseHandler.DatabaseContext context = mock(DatabaseHandler.DatabaseContext.class);
         when(context.getCluster()).thenReturn(fixture.cluster);
 
         Set<ConfiguredNode> nodes = new HashSet<>(fixture.cluster.clusterInfo().getConfiguredNodes().values());
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/MasterElectionTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/MasterElectionTest.java
index 8d32986bcaf..bf3efb17ddf 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/MasterElectionTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/MasterElectionTest.java
@@ -7,7 +7,6 @@ import com.yahoo.jrt.Supervisor;
 import com.yahoo.jrt.Target;
 import com.yahoo.jrt.Transport;
 import com.yahoo.jrt.slobrok.server.Slobrok;
-import java.util.logging.Level;
 import com.yahoo.vdslib.state.ClusterState;
 import com.yahoo.vdslib.state.NodeState;
 import com.yahoo.vdslib.state.NodeType;
@@ -22,6 +21,7 @@ import org.junit.rules.Timeout;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.TimeoutException;
+import java.util.logging.Level;
 import java.util.logging.Logger;
 import java.util.stream.Stream;
 
@@ -296,7 +296,7 @@ public class MasterElectionTest extends FleetControllerTest {
         for (FleetController fc : fleetControllers) {
             FleetControllerOptions myoptions = fc.getOptions();
             myoptions.zooKeeperServerAddress = zooKeeperServer.getAddress();
-            fc.updateOptions(myoptions, 0);
+            fc.updateOptions(myoptions);
             log.log(Level.INFO, "Should now have sent out new zookeeper server address " + myoptions.zooKeeperServerAddress + " to fleetcontroller " + myoptions.fleetControllerIndex);
         }
         timer.advanceTime(10 * 1000); // Wait long enough for fleetcontroller wanting to retry zookeeper connection
@@ -447,7 +447,7 @@ public class MasterElectionTest extends FleetControllerTest {
         FleetControllerOptions newOptions = options.clone();
         for (int i=0; i<fleetControllers.size(); ++i) {
             FleetControllerOptions nodeOptions = adjustConfig(newOptions, i, fleetControllers.size());
-            fleetControllers.get(i).updateOptions(nodeOptions, 2);
+            fleetControllers.get(i).updateOptions(nodeOptions);
         }
         waitForMaster(0);
         log.log(Level.INFO, "SHUTTING DOWN FLEET CONTROLLER 0");
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/NodeSlobrokConfigurationMembershipTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/NodeSlobrokConfigurationMembershipTest.java
index c1f1d0e1bc1..ea539cc13e0 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/NodeSlobrokConfigurationMembershipTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/NodeSlobrokConfigurationMembershipTest.java
@@ -46,7 +46,7 @@ public class NodeSlobrokConfigurationMembershipTest extends FleetControllerTest
         // cluster. If we do not re-fetch state from slobrok we risk racing
         nodeIndices.add(foreignNode);
         options.nodes = asConfiguredNodes(nodeIndices);
-        fleetController.updateOptions(options, 0);
+        fleetController.updateOptions(options);
         // Need to treat cluster as having 6 nodes due to ideal state algo semantics.
         // Note that we do not use subsetWaiter here since we want node 6 included.
         waitForState("version:\\d+ distributor:7 .4.s:d .5.s:d storage:7 .4.s:d .5.s:d");
@@ -65,13 +65,13 @@ public class NodeSlobrokConfigurationMembershipTest extends FleetControllerTest
         assertTrue(configuredNodes.remove(new ConfiguredNode(0, false)));
         configuredNodes.add(new ConfiguredNode(0, true));
         options.nodes = configuredNodes;
-        fleetController.updateOptions(options, 0);
+        fleetController.updateOptions(options);
 
         waitForState("version:\\d+ distributor:4 storage:4 .0.s:r");
 
         // Now remove the retired node entirely from config
         assertTrue(configuredNodes.remove(new ConfiguredNode(0, true)));
-        fleetController.updateOptions(options, 0);
+        fleetController.updateOptions(options);
 
         // The previously retired node should now be marked as down, as it no longer
         // exists from the point of view of the content cluster. We have to use a subset
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/RpcServerTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/RpcServerTest.java
index 05ee96500d5..fee1d33725c 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/RpcServerTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/RpcServerTest.java
@@ -346,7 +346,7 @@ public class RpcServerTest extends FleetControllerTest {
             options.slobrokConnectionSpecs = this.options.slobrokConnectionSpecs;
             this.options.maxInitProgressTime = 30000;
             this.options.stableStateTimePeriod = 60000;
-            fleetController.updateOptions(options, 0);
+            fleetController.updateOptions(options);
             waitForState("version:\\d+ distributor:7 storage:7 .0.s:m .1.s:m .2.s:r .3.s:r .4.s:r");
         }
 
@@ -376,7 +376,7 @@ public class RpcServerTest extends FleetControllerTest {
             options.slobrokConnectionSpecs = this.options.slobrokConnectionSpecs;
             this.options.maxInitProgressTime = 30000;
             this.options.stableStateTimePeriod = 60000;
-            fleetController.updateOptions(options, 0);
+            fleetController.updateOptions(options);
             waitForState("version:\\d+ distributor:7 storage:7 .0.s:m .1.s:m");
         }
 
@@ -415,7 +415,7 @@ public class RpcServerTest extends FleetControllerTest {
             options.slobrokConnectionSpecs = this.options.slobrokConnectionSpecs;
             this.options.maxInitProgressTime = 30000;
             this.options.stableStateTimePeriod = 60000;
-            fleetController.updateOptions(options, 0);
+            fleetController.updateOptions(options);
             waitForState("version:\\d+ distributor:5 storage:5");
         }
 
@@ -430,7 +430,7 @@ public class RpcServerTest extends FleetControllerTest {
             options.slobrokConnectionSpecs = this.options.slobrokConnectionSpecs;
             this.options.maxInitProgressTime = 30000;
             this.options.stableStateTimePeriod = 60000;
-            fleetController.updateOptions(options, 0);
+            fleetController.updateOptions(options);
             waitForState("version:\\d+ distributor:7 storage:7 .0.s:r .1.s:r .2.s:r .3.s:r .4.s:r");
         }
 
@@ -444,7 +444,7 @@ public class RpcServerTest extends FleetControllerTest {
             options.slobrokConnectionSpecs = this.options.slobrokConnectionSpecs;
             this.options.maxInitProgressTime = 30000;
             this.options.stableStateTimePeriod = 60000;
-            fleetController.updateOptions(options, 0);
+            fleetController.updateOptions(options);
             waitForState("version:\\d+ distributor:7 storage:7 .0.s:r .1.s:r .2.s:r .3.s:r .4.s:r");
         }
 
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/StateChangeTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/StateChangeTest.java
index 2a0ab389865..e7aae087626 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/StateChangeTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/StateChangeTest.java
@@ -16,12 +16,6 @@ import com.yahoo.vespa.clustercontroller.utils.util.NoMetricReporter;
 import org.junit.Before;
 import org.junit.Test;
 
-import static org.hamcrest.CoreMatchers.equalTo;
-import static org.hamcrest.MatcherAssert.assertThat;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
-
 import java.time.Duration;
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -29,6 +23,12 @@ import java.util.List;
 import java.util.Map;
 import java.util.logging.Logger;
 
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
 public class StateChangeTest extends FleetControllerTest {
 
     public static Logger log = Logger.getLogger(StateChangeTest.class.getName());
@@ -49,16 +49,17 @@ public class StateChangeTest extends FleetControllerTest {
             nodes.add(new Node(NodeType.DISTRIBUTOR, i));
         }
 
+        var context = new TestContext(options);
         communicator = new DummyCommunicator(nodes, timer);
-        MetricUpdater metricUpdater = new MetricUpdater(new NoMetricReporter(), options.fleetControllerIndex, options.clusterName);
+        var metricUpdater = new MetricUpdater(new NoMetricReporter(), options.fleetControllerIndex, options.clusterName);
         eventLog = new EventLog(timer, metricUpdater);
-        ContentCluster cluster = new ContentCluster(options.clusterName, options.nodes, options.storageDistribution);
-        NodeStateGatherer stateGatherer = new NodeStateGatherer(timer, timer, eventLog);
-        DatabaseHandler database = new DatabaseHandler(new ZooKeeperDatabaseFactory(), timer, options.zooKeeperServerAddress, options.fleetControllerIndex, timer);
-        StateChangeHandler stateGenerator = new StateChangeHandler(timer, eventLog);
-        SystemStateBroadcaster stateBroadcaster = new SystemStateBroadcaster(timer, timer);
-        MasterElectionHandler masterElectionHandler = new MasterElectionHandler(options.fleetControllerIndex, options.fleetControllerCount, timer, timer);
-        ctrl = new FleetController(timer, eventLog, cluster, stateGatherer, communicator, null, null, communicator, database, stateGenerator, stateBroadcaster, masterElectionHandler, metricUpdater, options);
+        var cluster = new ContentCluster(options.clusterName, options.nodes, options.storageDistribution);
+        var stateGatherer = new NodeStateGatherer(timer, timer, eventLog);
+        var database = new DatabaseHandler(context, new ZooKeeperDatabaseFactory(), timer, options.zooKeeperServerAddress, timer);
+        var stateGenerator = new StateChangeHandler(timer, eventLog);
+        var stateBroadcaster = new SystemStateBroadcaster(timer, timer);
+        var masterElectionHandler = new MasterElectionHandler(context, options.fleetControllerIndex, options.fleetControllerCount, timer, timer);
+        ctrl = new FleetController(context, timer, eventLog, cluster, stateGatherer, communicator, null, null, communicator, database, stateGenerator, stateBroadcaster, masterElectionHandler, metricUpdater, options);
 
         ctrl.tick();
         if (options.fleetControllerCount == 1) {
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/SystemStateBroadcasterTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/SystemStateBroadcasterTest.java
index dfbe4d5a8e8..84b479cfc29 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/SystemStateBroadcasterTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/SystemStateBroadcasterTest.java
@@ -55,8 +55,8 @@ public class SystemStateBroadcasterTest {
         }
     }
 
-    private static DatabaseHandler.Context dbContextFrom(ContentCluster cluster) {
-        return new DatabaseHandler.Context() {
+    private static DatabaseHandler.DatabaseContext dbContextFrom(ContentCluster cluster) {
+        return new DatabaseHandler.DatabaseContext() {
             @Override
             public ContentCluster getCluster() {
                 return cluster;
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/TestContext.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/TestContext.java
new file mode 100644
index 00000000000..1a7c2659bd6
--- /dev/null
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/TestContext.java
@@ -0,0 +1,17 @@
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.clustercontroller.core;
+
+/**
+ * @author hakon
+ */
+public class TestContext extends ContextImpl {
+    public TestContext(FleetControllerOptions options) {
+        super(options);
+    }
+
+    @Override
+    protected String withLogPrefix(String message) {
+        // Include fleet controller index in prefix in tests, since many may be running
+        return id() + ": " + message;
+    }
+}