Merge pull request #27479 from vespa-engine/hmusum/cluster-controller-cleanup-8

Hmusum/cluster controller cleanup 8

14 files changed, 139 insertions, 100 deletions

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 8027cec4e3c..a5fa0d08bb8 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
@@ -2,7 +2,6 @@
 package com.yahoo.vespa.clustercontroller.core;
 
 import com.yahoo.document.FixedBucketSpaces;
-import com.yahoo.exception.ExceptionUtils;
 import com.yahoo.vdslib.distribution.ConfiguredNode;
 import com.yahoo.vdslib.state.ClusterState;
 import com.yahoo.vdslib.state.Node;
@@ -22,10 +21,9 @@ import com.yahoo.vespa.clustercontroller.core.status.LegacyIndexPageRequestHandl
 import com.yahoo.vespa.clustercontroller.core.status.LegacyNodePageRequestHandler;
 import com.yahoo.vespa.clustercontroller.core.status.NodeHealthRequestHandler;
 import com.yahoo.vespa.clustercontroller.core.status.StatusHandler;
-import com.yahoo.vespa.clustercontroller.core.status.statuspage.StatusPageResponse;
 import com.yahoo.vespa.clustercontroller.core.status.statuspage.StatusPageServer;
 import com.yahoo.vespa.clustercontroller.utils.util.MetricReporter;
-import java.io.FileNotFoundException;
+
 import java.time.Duration;
 import java.time.Instant;
 import java.util.ArrayDeque;
@@ -37,7 +35,6 @@ import java.util.List;
 import java.util.Map;
 import java.util.Queue;
 import java.util.Set;
-import java.util.TimeZone;
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.logging.Level;
@@ -508,43 +505,6 @@ public class FleetController implements NodeListener, SlobrokListener, SystemSta
         }
     }
 
-    public StatusPageResponse fetchStatusPage(StatusPageServer.HttpRequest httpRequest) {
-        verifyInControllerThread();
-        StatusPageResponse.ResponseCode responseCode;
-        String message;
-        final String hiddenMessage;
-        try {
-            StatusPageServer.RequestHandler handler = statusRequestRouter.resolveHandler(httpRequest);
-            if (handler == null) {
-                throw new FileNotFoundException("No handler found for request: " + httpRequest.getPath());
-            }
-            return handler.handle(httpRequest);
-        } 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);
-            context.log(logger, Level.FINE, () -> "Unknown exception thrown for request " + httpRequest.getRequest() + ": " + hiddenMessage);
-        }
-
-        TimeZone tz = TimeZone.getTimeZone("UTC");
-        long currentTime = timer.getCurrentTimeInMillis();
-        StatusPageResponse response = new StatusPageResponse();
-        StringBuilder content = new StringBuilder();
-        response.setContentType("text/html");
-        response.setResponseCode(responseCode);
-        content.append("<!-- Answer to request ").append(httpRequest.getRequest()).append(" -->\n");
-        content.append("<p>UTC time when creating this page: ").append(RealTimer.printDateNoMilliSeconds(currentTime, tz)).append("</p>");
-        response.writeHtmlHeader(content, message);
-        response.writeHtmlFooter(content, hiddenMessage);
-        response.writeContent(content.toString());
-
-        return response;
-    }
-
     public void tick() throws Exception {
         synchronized (monitor) {
             boolean didWork;
@@ -635,7 +595,8 @@ public class FleetController implements NodeListener, SlobrokListener, SystemSta
     private boolean processAnyPendingStatusPageRequest() {
         StatusPageServer.HttpRequest statusRequest = statusPageServer.getCurrentHttpRequest();
         if (statusRequest != null) {
-            statusPageServer.answerCurrentStatusRequest(fetchStatusPage(statusRequest));
+            verifyInControllerThread();
+            statusPageServer.fetchStatusPage(statusRequest, statusRequestRouter, timer);
             return true;
         }
         return false;
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/MissingIdException.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/MissingIdException.java
index 21229b4b358..18a3b923908 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/MissingIdException.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/MissingIdException.java
@@ -4,14 +4,12 @@ package com.yahoo.vespa.clustercontroller.core.restapiv2;
 import com.yahoo.vdslib.state.Node;
 import com.yahoo.vespa.clustercontroller.utils.staterestapi.errors.MissingUnitException;
 
+import java.util.List;
+
 public class MissingIdException extends MissingUnitException {
 
-    private static String[] createPath(String cluster, Node n) {
-        String[] path = new String[3];
-        path[0] = cluster;
-        path[1] = n.getType().toString();
-        path[2] = String.valueOf(n.getIndex());
-        return path;
+    private static List<String> createPath(String cluster, Node n) {
+        return List.of(cluster, n.getType().toString(), String.valueOf(n.getIndex()));
     }
 
     public MissingIdException(String cluster, Node n) {
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/UnitPathResolver.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/UnitPathResolver.java
index 11fd5f39fad..0db11cad955 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/UnitPathResolver.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/UnitPathResolver.java
@@ -7,6 +7,7 @@ import com.yahoo.vespa.clustercontroller.utils.staterestapi.errors.MissingUnitEx
 import com.yahoo.vespa.clustercontroller.utils.staterestapi.errors.OperationNotSupportedForUnitException;
 import com.yahoo.vespa.clustercontroller.utils.staterestapi.errors.StateRestApiException;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 
 public class UnitPathResolver<T> {
@@ -22,10 +23,10 @@ public class UnitPathResolver<T> {
 
     public static abstract class AbstractVisitor<T> implements Visitor<T> {
 
-        private final String[] path;
+        private final List<String> path;
         private final String failureMessage;
 
-        public AbstractVisitor(String[] path, String failureMessage) {
+        public AbstractVisitor(List<String> path, String failureMessage) {
             this.path = path;
             this.failureMessage = failureMessage;
         }
@@ -46,41 +47,41 @@ public class UnitPathResolver<T> {
         this.fleetControllers = new HashMap<>(fleetControllers);
     }
 
-    public RemoteClusterControllerTaskScheduler resolveFleetController(String[] path) throws StateRestApiException {
-        if (path.length == 0) return null;
-        RemoteClusterControllerTaskScheduler fc = fleetControllers.get(path[0]);
+    public RemoteClusterControllerTaskScheduler resolveFleetController(List<String> path) throws StateRestApiException {
+        if (path.size() == 0) return null;
+        RemoteClusterControllerTaskScheduler fc = fleetControllers.get(path.get(0));
         if (fc == null) {
             throw new MissingUnitException(path, 0);
         }
         return fc;
     }
 
-    public Request<? extends T> visit(String[] path, Visitor<T> visitor) throws StateRestApiException {
-        if (path.length == 0) {
+    public Request<? extends T> visit(List<String> path, Visitor<T> visitor) throws StateRestApiException {
+        if (path.size() == 0) {
             return visitor.visitGlobal();
         }
-        RemoteClusterControllerTaskScheduler fc = fleetControllers.get(path[0]);
+        RemoteClusterControllerTaskScheduler fc = fleetControllers.get(path.get(0));
         if (fc == null) throw new MissingUnitException(path, 0);
-        Id.Cluster cluster = new Id.Cluster(path[0]);
-        if (path.length == 1) {
+        Id.Cluster cluster = new Id.Cluster(path.get(0));
+        if (path.size() == 1) {
             return visitor.visitCluster(cluster);
         }
         Id.Service service;
         try{
-            service = new Id.Service(cluster, NodeType.get(path[1]));
+            service = new Id.Service(cluster, NodeType.get(path.get(1)));
         } catch (IllegalArgumentException e) {
             throw new MissingUnitException(path, 1);
         }
-        if (path.length == 2) {
+        if (path.size() == 2) {
             return visitor.visitService(service);
         }
         Id.Node node;
         try{
-            node = new Id.Node(service, Integer.valueOf(path[2]));
+            node = new Id.Node(service, Integer.parseInt(path.get(2)));
         } catch (NumberFormatException e) {
             throw new MissingUnitException(path, 2);
         }
-        if (path.length == 3) {
+        if (path.size() == 3) {
             return visitor.visitNode(node);
         }
         throw new MissingUnitException(path, 4);
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/status/StatusHandler.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/status/StatusHandler.java
index 65b06afb0c5..6ed121284b6 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/status/StatusHandler.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/status/StatusHandler.java
@@ -1,14 +1,20 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.clustercontroller.core.status;
 
+import com.yahoo.exception.ExceptionUtils;
+import com.yahoo.vespa.clustercontroller.core.RealTimer;
+import com.yahoo.vespa.clustercontroller.core.Timer;
 import com.yahoo.vespa.clustercontroller.core.status.statuspage.StatusPageResponse;
 import com.yahoo.vespa.clustercontroller.core.status.statuspage.StatusPageServer;
 import com.yahoo.vespa.clustercontroller.utils.communication.http.HttpRequest;
 import com.yahoo.vespa.clustercontroller.utils.communication.http.HttpRequestHandler;
 import com.yahoo.vespa.clustercontroller.utils.communication.http.HttpResult;
+
+import java.io.FileNotFoundException;
 import java.io.StringWriter;
 import java.nio.charset.StandardCharsets;
 import java.util.Map;
+import java.util.TimeZone;
 import java.util.logging.Logger;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -42,6 +48,46 @@ public class StatusHandler implements HttpRequestHandler {
                 return r;
             }
         }
+
+        public void fetchStatusPage(StatusPageServer.HttpRequest httpRequest,
+                                    StatusPageServer.PatternRequestRouter statusRequestRouter,
+                                    Timer timer) {
+            StatusPageResponse.ResponseCode responseCode;
+            String message;
+            final String hiddenMessage;
+            try {
+                StatusPageServer.RequestHandler handler = statusRequestRouter.resolveHandler(httpRequest);
+                if (handler == null) {
+                    throw new FileNotFoundException("No handler found for request: " + httpRequest.getPath());
+                }
+                answerCurrentStatusRequest(handler.handle(httpRequest));
+                return;
+            } 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);
+            }
+
+            TimeZone tz = TimeZone.getTimeZone("UTC");
+            long currentTime = timer.getCurrentTimeInMillis();
+            StatusPageResponse response = new StatusPageResponse();
+            StringBuilder content = new StringBuilder();
+            response.setContentType("text/html");
+            response.setResponseCode(responseCode);
+            content.append("<!-- Answer to request ").append(httpRequest.getRequest()).append(" -->\n");
+            content.append("<p>UTC time when creating this page: ").append(RealTimer.printDateNoMilliSeconds(currentTime, tz)).append("</p>");
+            response.writeHtmlHeader(content, message);
+            response.writeHtmlFooter(content, hiddenMessage);
+            response.writeContent(content.toString());
+
+
+            answerCurrentStatusRequest(response);
+        }
+
         public void answerCurrentStatusRequest(StatusPageResponse r) {
             synchronized (answerMonitor) {
                 response = r;
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/StateRequests.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/StateRequests.java
new file mode 100644
index 00000000000..f0f98120d72
--- /dev/null
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/StateRequests.java
@@ -0,0 +1,30 @@
+package com.yahoo.vespa.clustercontroller.core;
+
+import com.yahoo.vespa.clustercontroller.utils.staterestapi.requests.UnitStateRequest;
+
+import java.util.List;
+
+public class StateRequests {
+
+    public static class Get extends StateRequests implements UnitStateRequest {
+        private final List<String> path;
+        private final int recursive;
+
+        public Get(String req, int recursive) {
+            path = req.isEmpty() ? List.of() : List.of(req.split("/"));
+            this.recursive = recursive;
+        }
+
+        @Override
+        public int getRecursiveLevels() {
+            return recursive;
+        }
+
+        @Override
+        public List<String> getUnitPath() {
+            return path;
+        }
+
+    }
+
+}
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/restapiv2/StateRestApiTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/restapiv2/StateRestApiTest.java
index 205d5b05b29..bec12ccb195 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/restapiv2/StateRestApiTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/restapiv2/StateRestApiTest.java
@@ -22,6 +22,7 @@ import java.util.Arrays;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.TreeMap;
@@ -36,18 +37,18 @@ public abstract class StateRestApiTest {
     Map<Integer, ClusterControllerStateRestAPI.Socket> ccSockets;
 
     public static class StateRequest implements UnitStateRequest {
-        private final String[] path;
+        private final List<String> path;
         private final int recursive;
 
         StateRequest(String req, int recursive) {
-            path = req.isEmpty() ? new String[0] : req.split("/");
+            path = req.isEmpty() ? List.of() : List.of(req.split("/"));
             this.recursive = recursive;
         }
         @Override
         public int getRecursiveLevels() { return recursive;
         }
         @Override
-        public String[] getUnitPath() { return path; }
+        public List<String> getUnitPath() { return path; }
     }
 
     protected void setUp(boolean dontInitializeNode2) {
diff --git a/clustercontroller-utils/src/main/java/com/yahoo/vespa/clustercontroller/utils/staterestapi/errors/MissingUnitException.java b/clustercontroller-utils/src/main/java/com/yahoo/vespa/clustercontroller/utils/staterestapi/errors/MissingUnitException.java
index 838e13fc4ee..58a862f4878 100644
--- a/clustercontroller-utils/src/main/java/com/yahoo/vespa/clustercontroller/utils/staterestapi/errors/MissingUnitException.java
+++ b/clustercontroller-utils/src/main/java/com/yahoo/vespa/clustercontroller/utils/staterestapi/errors/MissingUnitException.java
@@ -1,19 +1,21 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.clustercontroller.utils.staterestapi.errors;
 
+import java.util.List;
+
 public class MissingUnitException extends StateRestApiException {
 
-    private static String createMessage(String[] path, int level) {
+    private static String createMessage(List<String> path, int level) {
         StringBuilder sb = new StringBuilder();
         sb.append("No such resource '");
         for (int i=0; i<=level; ++i) {
             if (i != 0) sb.append('/');
-            sb.append(path[i]);
+            sb.append(path.get(i));
         }
         return sb.append("'.").toString();
     }
 
-    public MissingUnitException(String[] path, int level) {
+    public MissingUnitException(List<String> path, int level) {
         super(createMessage(path, level));
         setHtmlCode(404);
         setHtmlStatus(getMessage());
diff --git a/clustercontroller-utils/src/main/java/com/yahoo/vespa/clustercontroller/utils/staterestapi/errors/OperationNotSupportedForUnitException.java b/clustercontroller-utils/src/main/java/com/yahoo/vespa/clustercontroller/utils/staterestapi/errors/OperationNotSupportedForUnitException.java
index 342f568eacc..abc55d68bc6 100644
--- a/clustercontroller-utils/src/main/java/com/yahoo/vespa/clustercontroller/utils/staterestapi/errors/OperationNotSupportedForUnitException.java
+++ b/clustercontroller-utils/src/main/java/com/yahoo/vespa/clustercontroller/utils/staterestapi/errors/OperationNotSupportedForUnitException.java
@@ -2,16 +2,17 @@
 package com.yahoo.vespa.clustercontroller.utils.staterestapi.errors;
 
 import java.util.Arrays;
+import java.util.List;
 
 public class OperationNotSupportedForUnitException extends StateRestApiException {
 
-    private static String createMessage(String[] path, String description) {
+    private static String createMessage(List<String> path, String description) {
         return new StringBuilder()
-                .append(Arrays.toString(path)).append(": ").append(description)
+                .append(Arrays.toString(path.toArray())).append(": ").append(description)
                 .toString();
     }
 
-    public OperationNotSupportedForUnitException(String path[], String description) {
+    public OperationNotSupportedForUnitException(List<String> path, String description) {
         super(createMessage(path, description));
         setHtmlCode(405);
         setHtmlStatus("Operation not supported for resource");
diff --git a/clustercontroller-utils/src/main/java/com/yahoo/vespa/clustercontroller/utils/staterestapi/requests/UnitRequest.java b/clustercontroller-utils/src/main/java/com/yahoo/vespa/clustercontroller/utils/staterestapi/requests/UnitRequest.java
index 53abfff8aba..52bef3b09c0 100644
--- a/clustercontroller-utils/src/main/java/com/yahoo/vespa/clustercontroller/utils/staterestapi/requests/UnitRequest.java
+++ b/clustercontroller-utils/src/main/java/com/yahoo/vespa/clustercontroller/utils/staterestapi/requests/UnitRequest.java
@@ -1,8 +1,10 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.clustercontroller.utils.staterestapi.requests;
 
+import java.util.List;
+
 public interface UnitRequest {
 
-    String[] getUnitPath();
+    List<String> getUnitPath();
 
 }
diff --git a/clustercontroller-utils/src/main/java/com/yahoo/vespa/clustercontroller/utils/staterestapi/response/SetResponse.java b/clustercontroller-utils/src/main/java/com/yahoo/vespa/clustercontroller/utils/staterestapi/response/SetResponse.java
index 1c704ea3b63..2287abb5ca7 100644
--- a/clustercontroller-utils/src/main/java/com/yahoo/vespa/clustercontroller/utils/staterestapi/response/SetResponse.java
+++ b/clustercontroller-utils/src/main/java/com/yahoo/vespa/clustercontroller/utils/staterestapi/response/SetResponse.java
@@ -24,7 +24,7 @@ public class SetResponse {
     public boolean getWasModified() { return wasModified; }
 
     /**
-     * Human readable reason.
+     * Human-readable reason.
      *
      * @return reason as string
      */
diff --git a/clustercontroller-utils/src/main/java/com/yahoo/vespa/clustercontroller/utils/staterestapi/server/RestApiHandler.java b/clustercontroller-utils/src/main/java/com/yahoo/vespa/clustercontroller/utils/staterestapi/server/RestApiHandler.java
index 654481aee33..ceec4f67e1b 100644
--- a/clustercontroller-utils/src/main/java/com/yahoo/vespa/clustercontroller/utils/staterestapi/server/RestApiHandler.java
+++ b/clustercontroller-utils/src/main/java/com/yahoo/vespa/clustercontroller/utils/staterestapi/server/RestApiHandler.java
@@ -25,7 +25,6 @@ import java.time.Clock;
 import java.time.Duration;
 import java.time.Instant;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
@@ -64,7 +63,7 @@ public class RestApiHandler implements HttpRequestHandler {
         Instant start = clock.instant();
 
         try{
-            final String[] unitPath = createUnitPath(request);
+            List<String> unitPath = createUnitPath(request);
             if (request.getHttpOperation().equals(HttpRequest.HttpOp.GET)) {
                 final int recursiveLevel = getRecursiveLevel(request);
                 UnitResponse data = restApi.getState(new UnitStateRequest() {
@@ -73,9 +72,7 @@ public class RestApiHandler implements HttpRequestHandler {
                         return recursiveLevel;
                     }
                     @Override
-                    public String[] getUnitPath() {
-                        return unitPath;
-                    }
+                    public List<String> getUnitPath() { return unitPath; }
                 });
                 return new JsonHttpResult().setJson(jsonWriter.createJson(data));
             } else {
@@ -87,7 +84,7 @@ public class RestApiHandler implements HttpRequestHandler {
                         return setRequestData.stateMap;
                     }
                     @Override
-                    public String[] getUnitPath() {
+                    public List<String> getUnitPath() {
                         return unitPath;
                     }
                     @Override
@@ -137,9 +134,9 @@ public class RestApiHandler implements HttpRequestHandler {
         }
     }
 
-    private String[] createUnitPath(HttpRequest request) {
-        List<String> path = Arrays.asList(request.getPath().split("/"));
-        return path.subList(3, path.size()).toArray(new String[0]);
+    private List<String> createUnitPath(HttpRequest request) {
+        List<String> path = List.of(request.getPath().split("/"));
+        return path.subList(3, path.size());
     }
 
     private int getRecursiveLevel(HttpRequest request) throws StateRestApiException {
diff --git a/clustercontroller-utils/src/main/java/com/yahoo/vespa/clustercontroller/utils/util/ComponentMetricReporter.java b/clustercontroller-utils/src/main/java/com/yahoo/vespa/clustercontroller/utils/util/ComponentMetricReporter.java
index bed2ddcecd0..cde44b76fcb 100644
--- a/clustercontroller-utils/src/main/java/com/yahoo/vespa/clustercontroller/utils/util/ComponentMetricReporter.java
+++ b/clustercontroller-utils/src/main/java/com/yahoo/vespa/clustercontroller/utils/util/ComponentMetricReporter.java
@@ -1,12 +1,12 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-/**
- * Metric reporter wrapper to add component name prefix and common dimensions.
- */
 package com.yahoo.vespa.clustercontroller.utils.util;
 
 import java.util.Map;
 import java.util.TreeMap;
 
+/**
+ * Metric reporter wrapper to add component name prefix and common dimensions.
+ */
 public class ComponentMetricReporter implements MetricReporter {
 
     private final MetricReporter impl;
diff --git a/clustercontroller-utils/src/test/java/com/yahoo/vespa/clustercontroller/utils/staterestapi/DummyStateApi.java b/clustercontroller-utils/src/test/java/com/yahoo/vespa/clustercontroller/utils/staterestapi/DummyStateApi.java
index d611b0c0ea8..2fcbf22aa59 100644
--- a/clustercontroller-utils/src/test/java/com/yahoo/vespa/clustercontroller/utils/staterestapi/DummyStateApi.java
+++ b/clustercontroller-utils/src/test/java/com/yahoo/vespa/clustercontroller/utils/staterestapi/DummyStateApi.java
@@ -10,6 +10,7 @@ import com.yahoo.vespa.clustercontroller.utils.staterestapi.requests.UnitStateRe
 import com.yahoo.vespa.clustercontroller.utils.staterestapi.response.*;
 
 import java.util.LinkedHashMap;
+import java.util.List;
 import java.util.Map;
 
 public class DummyStateApi implements StateRestAPI {
@@ -28,8 +29,8 @@ public class DummyStateApi implements StateRestAPI {
     }
 
     public class SubUnitListImpl implements SubUnitList {
-        private Map<String, String> links = new LinkedHashMap<>();
-        private Map<String, UnitResponse> values = new LinkedHashMap<>();
+        private final Map<String, String> links = new LinkedHashMap<>();
+        private final Map<String, UnitResponse> values = new LinkedHashMap<>();
 
         @Override
         public Map<String, String> getSubUnitLinks() { return links; }
@@ -156,18 +157,18 @@ public class DummyStateApi implements StateRestAPI {
     @Override
     public UnitResponse getState(UnitStateRequest request) throws StateRestApiException {
         checkForInducedException();
-        String[] path = request.getUnitPath();
-        if (path.length == 0) {
+        List<String> path = request.getUnitPath();
+        if (path.size() == 0) {
             return getClusterList(request.getRecursiveLevels());
         }
-        final DummyBackend.Cluster c = backend.getClusters().get(path[0]);
+        DummyBackend.Cluster c = backend.getClusters().get(path.get(0));
         if (c == null) throw new MissingUnitException(path, 0);
-        if (path.length == 1) {
+        if (path.size() == 1) {
             return getClusterState(c, request.getRecursiveLevels());
         }
-        final DummyBackend.Node n = c.nodes.get(path[1]);
+        DummyBackend.Node n = c.nodes.get(path.get(1));
         if (n == null) throw new MissingUnitException(path, 1);
-        if (path.length == 2) {
+        if (path.size() == 2) {
             return getNodeState(n);
         }
         throw new MissingUnitException(path, 3);
@@ -176,15 +177,15 @@ public class DummyStateApi implements StateRestAPI {
     @Override
     public SetResponse setUnitState(SetUnitStateRequest request) throws StateRestApiException {
         checkForInducedException();
-        String[] path = request.getUnitPath();
-        if (path.length != 2) {
+        List<String> path = request.getUnitPath();
+        if (path.size() != 2) {
             throw new OperationNotSupportedForUnitException(
                     path, "You can only set states on nodes");
         }
         DummyBackend.Node n = null;
-        DummyBackend.Cluster c = backend.getClusters().get(path[0]);
+        DummyBackend.Cluster c = backend.getClusters().get(path.get(0));
         if (c != null) {
-            n = c.nodes.get(path[1]);
+            n = c.nodes.get(path.get(1));
         }
         if (n == null) throw new MissingUnitException(path, 2);
         Map<String, UnitState> newState = request.getNewState();
diff --git a/clustercontroller-utils/src/test/java/com/yahoo/vespa/clustercontroller/utils/staterestapi/StateRestAPITest.java b/clustercontroller-utils/src/test/java/com/yahoo/vespa/clustercontroller/utils/staterestapi/StateRestAPITest.java
index 47b12f883ff..29e33b7906a 100644
--- a/clustercontroller-utils/src/test/java/com/yahoo/vespa/clustercontroller/utils/staterestapi/StateRestAPITest.java
+++ b/clustercontroller-utils/src/test/java/com/yahoo/vespa/clustercontroller/utils/staterestapi/StateRestAPITest.java
@@ -19,6 +19,7 @@ import com.yahoo.vespa.clustercontroller.utils.staterestapi.server.RestApiHandle
 import com.yahoo.vespa.clustercontroller.utils.test.TestTransport;
 import org.junit.jupiter.api.Test;
 
+import java.util.List;
 import java.util.Optional;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
@@ -486,9 +487,7 @@ public class StateRestAPITest {
             assertEquals(expected, result.getContent().toString());
         }
         {
-            String path[] = new String[1];
-            path[0] = "foo";
-            stateApi.induceException(new OperationNotSupportedForUnitException(path, "Foo"));
+            stateApi.induceException(new OperationNotSupportedForUnitException(List.of("foo"), "Foo"));
             HttpResult result = execute(new HttpRequest().setPath("/cluster/v2"));
             assertEquals(405, result.getHttpReturnCode(), result.toString(true));
             assertEquals("Operation not supported for resource", result.getHttpReturnCodeDescription(), result.toString(true));