Log correct dispatched requests

3 files changed, 27 insertions, 8 deletions

diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/dns/NameServiceQueue.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/dns/NameServiceQueue.java
index ee5d50414c1..786547d4a67 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/dns/NameServiceQueue.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/dns/NameServiceQueue.java
@@ -1,7 +1,6 @@
 // Copyright 2019 Oath Inc. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.hosted.controller.dns;
 
-import java.util.logging.Level;
 import com.yahoo.vespa.hosted.controller.api.integration.dns.NameService;
 
 import java.util.ArrayList;
@@ -10,6 +9,8 @@ import java.util.Collections;
 import java.util.List;
 import java.util.Objects;
 import java.util.concurrent.LinkedBlockingDeque;
+import java.util.function.UnaryOperator;
+import java.util.logging.Level;
 import java.util.logging.Logger;
 
 /**
@@ -39,12 +40,14 @@ public class NameServiceQueue {
         return Collections.unmodifiableCollection(requests);
     }
 
-    /** Returns a copy of this containing only the n most recent requests */
+    /** Returns a copy of this containing the last n requests */
     public NameServiceQueue last(int n) {
-        requireNonNegative(n);
-        if (requests.size() <= n) return this;
-        List<NameServiceRequest> requests = new ArrayList<>(this.requests);
-        return new NameServiceQueue(requests.subList(requests.size() - n, requests.size()));
+        return resize(n, (requests) -> requests.subList(requests.size() - n, requests.size()));
+    }
+
+    /** Returns a copy of this containing the first n requests */
+    public NameServiceQueue first(int n) {
+        return resize(n, (requests) -> requests.subList(0, n));
     }
 
     /** Returns a copy of this with given request queued according to priority */
@@ -58,6 +61,7 @@ public class NameServiceQueue {
         return queue;
     }
 
+    /** Returns a copy of this with given request added */
     public NameServiceQueue with(NameServiceRequest request) {
         return with(request, Priority.normal);
     }
@@ -91,6 +95,13 @@ public class NameServiceQueue {
         return requests.toString();
     }
 
+    private NameServiceQueue resize(int n, UnaryOperator<List<NameServiceRequest>> resizer) {
+        requireNonNegative(n);
+        if (requests.size() <= n) return this;
+        List<NameServiceRequest> requests = new ArrayList<>(this.requests);
+        return new NameServiceQueue(resizer.apply(requests));
+    }
+
     private static void requireNonNegative(int n) {
         if (n < 0) throw new IllegalArgumentException("n must be >= 0, got " + n);
     }
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/maintenance/NameServiceDispatcher.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/maintenance/NameServiceDispatcher.java
index 73daef7c2b0..e7eaf083a57 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/maintenance/NameServiceDispatcher.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/maintenance/NameServiceDispatcher.java
@@ -45,7 +45,7 @@ public class NameServiceDispatcher extends ControllerMaintainer {
             var remaining = queue.dispatchTo(nameService, requestCount);
             if (queue == remaining) return; // Queue unchanged
 
-            var dispatched = queue.last(requestCount);
+            var dispatched = queue.first(requestCount);
             if (!dispatched.requests().isEmpty()) {
                 log.log(Level.INFO, "Dispatched name service request(s) in " +
                                        Duration.between(instant, clock.instant()) +
diff --git a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/dns/NameServiceQueueTest.java b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/dns/NameServiceQueueTest.java
index d0362ae98b8..30ed9b5432c 100644
--- a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/dns/NameServiceQueueTest.java
+++ b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/dns/NameServiceQueueTest.java
@@ -74,13 +74,21 @@ public class NameServiceQueueTest {
         assertTrue(queue.requests().isEmpty());
         assertTrue("Removed " + r1, nameService.findRecords(Record.Type.CNAME, r1.name()).isEmpty());
 
-        // Keep n most recent requests
+        // Keep n last requests
         queue = queue.with(req1).with(req2).with(req3).with(req4).with(req6)
                      .last(2);
         assertEquals(List.of(req4, req6), List.copyOf(queue.requests()));
         assertSame(queue, queue.last(2));
         assertSame(queue, queue.last(10));
         assertTrue(queue.last(0).requests().isEmpty());
+
+        // Keep n first requests
+        queue = NameServiceQueue.EMPTY.with(req1).with(req2).with(req3).with(req4).with(req6)
+                                      .first(3);
+        assertEquals(List.of(req1, req2, req3), List.copyOf(queue.requests()));
+        assertSame(queue, queue.first(3));
+        assertSame(queue, queue.first(10));
+        assertTrue(queue.first(0).requests().isEmpty());
     }
 
 }