diff --git a/.editorconfig b/.editorconfig
index a9a165bae..6ef5d690a 100644
--- a/.editorconfig
+++ b/.editorconfig
@@ -12,6 +12,9 @@ end_of_line = lf
 [{*.bat,*.cmd}]
 end_of_line = crlf
 
+[{*.mustache,*.ftl}]
+insert_final_newline = false
+
 [*.java]
 indent_size = 4
 tab_width = 4
diff --git a/.github/workflows/graalvm-latest.yml b/.github/workflows/graalvm-latest.yml
index bfbfff345..d150aa606 100644
--- a/.github/workflows/graalvm-latest.yml
+++ b/.github/workflows/graalvm-latest.yml
@@ -34,7 +34,9 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       max-parallel: 6
-      matrix: ${{ fromJson(needs.build_matrix.outputs.matrix) }}
+      matrix:
+        java: ['17', '21']
+        native_test_task: ${{ fromJson(needs.build_matrix.outputs.matrix).native_test_task }}
     env:
       GRADLE_ENTERPRISE_ACCESS_KEY: ${{ secrets.GRADLE_ENTERPRISE_ACCESS_KEY }}
       GRADLE_ENTERPRISE_CACHE_USERNAME: ${{ secrets.GRADLE_ENTERPRISE_CACHE_USERNAME }}
@@ -46,7 +48,7 @@ jobs:
         id: pre-build
         with:
           distribution: 'graalvm'
-          java: '17'
+          java: ${{ matrix.java }}
       - name: Build Steps
         uses: micronaut-projects/github-actions/graalvm/build@master
         id: build
@@ -60,4 +62,4 @@ jobs:
         uses: micronaut-projects/github-actions/graalvm/post-build@master
         id: post-build
         with:
-          java: '17'
+          java: ${{ matrix.java }}
diff --git a/.github/workflows/gradle.yml b/.github/workflows/gradle.yml
index f60182451..7c0d4941b 100644
--- a/.github/workflows/gradle.yml
+++ b/.github/workflows/gradle.yml
@@ -19,7 +19,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        java: ['17']
+        java: ['17', '21']
     env:
       GRADLE_ENTERPRISE_ACCESS_KEY: ${{ secrets.GRADLE_ENTERPRISE_ACCESS_KEY }}
       GRADLE_ENTERPRISE_CACHE_USERNAME: ${{ secrets.GRADLE_ENTERPRISE_CACHE_USERNAME }}
@@ -64,7 +64,7 @@ jobs:
           ./gradlew check --no-daemon --continue
 
       - name: "🔎 Run static analysis"
-        if: env.SONAR_TOKEN != ''
+        if: env.SONAR_TOKEN != '' && matrix.java == '17'
         run: |
           ./gradlew sonar
 
diff --git a/settings.gradle b/settings.gradle
index 2b5613f09..6aca0e2c8 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -9,7 +9,7 @@ pluginManagement {
 }
 
 plugins {
-    id 'io.micronaut.build.shared.settings' version '6.5.6'
+    id 'io.micronaut.build.shared.settings' version '6.6.0'
 }
 rootProject.name = 'testresources-parent'
 
diff --git a/test-resources-server/src/test/resources/logback.xml b/test-resources-server/src/test/resources/logback.xml
index 44b79c40d..0c171e80f 100644
--- a/test-resources-server/src/test/resources/logback.xml
+++ b/test-resources-server/src/test/resources/logback.xml
@@ -11,4 +11,6 @@
     <root level="info">
         <appender-ref ref="STDOUT" />
     </root>
+    <logger name="io.micronaut.testresources.server" level="debug" />
+    <logger name="io.micronaut.testresources.testcontainers" level="trace" />
 </configuration>
diff --git a/test-resources-testcontainers/src/main/java/io/micronaut/testresources/testcontainers/TestContainers.java b/test-resources-testcontainers/src/main/java/io/micronaut/testresources/testcontainers/TestContainers.java
index 9e5ba0d21..8b9335bdd 100644
--- a/test-resources-testcontainers/src/main/java/io/micronaut/testresources/testcontainers/TestContainers.java
+++ b/test-resources-testcontainers/src/main/java/io/micronaut/testresources/testcontainers/TestContainers.java
@@ -52,6 +52,21 @@ private TestContainers() {
 
     }
 
+    private static <B> B withLock(String description, Supplier<B> supplier) {
+        LOCK.lock();
+        if (LOGGER.isTraceEnabled()) {
+            LOGGER.trace("Locked for {}", description);
+        }
+        try {
+            return supplier.get();
+        } finally {
+            if (LOGGER.isTraceEnabled()) {
+                LOGGER.trace("Unlocked for {}", description);
+            }
+            LOCK.unlock();
+        }
+    }
+
     /**
      * Returns a test container and caches it, so that if the same owner
      * and properties are requested, we can return an existing container.
@@ -71,19 +86,18 @@ static <T extends GenericContainer<? extends T>> T getOrCreate(String requestedP
                                                                    Map<String, Object> query,
                                                                    Supplier<T> creator) {
         Key key = Key.of(owner, name, Scope.from(query), query);
-        LOCK.lock();
-        @SuppressWarnings("unchecked")
-        T container = (T) CONTAINERS_BY_KEY.get(key);
-        if (container == null) {
-            container = creator.get();
-            LOGGER.info("Starting test container {}", name);
-            container.start();
-            CONTAINERS_BY_KEY.put(key, container);
-        }
-        CONTAINERS_BY_PROPERTY.computeIfAbsent(requestedProperty, e -> new LinkedHashSet<>())
-            .add(container);
-        LOCK.unlock();
-        return container;
+        return withLock("getOrCreate", () -> {
+            T container = (T) CONTAINERS_BY_KEY.get(key);
+            if (container == null) {
+                container = creator.get();
+                LOGGER.info("Starting test container {}", name);
+                container.start();
+                CONTAINERS_BY_KEY.put(key, container);
+            }
+            CONTAINERS_BY_PROPERTY.computeIfAbsent(requestedProperty, e -> new LinkedHashSet<>())
+                .add(container);
+            return container;
+        });
     }
 
     /**
@@ -101,9 +115,8 @@ public static Map<Scope, List<GenericContainer<?>>> listByScope(String id) {
     }
 
     private static Map<Scope, List<GenericContainer<?>>> listByScope(Scope scope) {
-        LOCK.lock();
-        try {
-            return CONTAINERS_BY_KEY.entrySet()
+        return withLock("listByScope", () ->
+            CONTAINERS_BY_KEY.entrySet()
                 .stream()
                 .filter(entry -> scope.includes(entry.getKey().scope))
                 .collect(Collectors.groupingBy(
@@ -112,26 +125,22 @@ private static Map<Scope, List<GenericContainer<?>>> listByScope(Scope scope) {
                         Map.Entry::getValue,
                         Collectors.toList()
                     )
-                ));
-        } finally {
-            LOCK.unlock();
-        }
+                ))
+        );
     }
 
+    @SuppressWarnings("java:S6204") // toList() breaks the return type
     private static List<GenericContainer<?>> filterByScope(Scope scope, Set<GenericContainer<?>> containers) {
         if (containers.isEmpty()) {
             return Collections.emptyList();
         }
-        LOCK.lock();
-        try {
-            return CONTAINERS_BY_KEY.entrySet()
+        return withLock("filterByScope", () ->
+            CONTAINERS_BY_KEY.entrySet()
                 .stream()
                 .filter(entry -> containers.contains(entry.getValue()) && scope.includes(entry.getKey().scope))
                 .map(Map.Entry::getValue)
-                .collect(Collectors.toList());
-        } finally {
-            LOCK.unlock();
-        }
+                .collect(Collectors.toList())
+        );
     }
 
     public static Network network(String name) {
@@ -139,18 +148,18 @@ public static Network network(String name) {
     }
 
     public static boolean closeAll() {
-        LOCK.lock();
-        boolean closed = false;
-        for (GenericContainer<?> container : CONTAINERS_BY_KEY.values()) {
-            container.close();
-            closed = true;
-        }
-        CONTAINERS_BY_KEY.clear();
-        CONTAINERS_BY_PROPERTY.clear();
-        NETWORKS_BY_KEY.values().forEach(Network::close);
-        NETWORKS_BY_KEY.clear();
-        LOCK.unlock();
-        return closed;
+        return withLock("closeAll", () -> {
+            boolean closed = false;
+            for (GenericContainer<?> container : CONTAINERS_BY_KEY.values()) {
+                container.close();
+                closed = true;
+            }
+            CONTAINERS_BY_KEY.clear();
+            CONTAINERS_BY_PROPERTY.clear();
+            NETWORKS_BY_KEY.values().forEach(Network::close);
+            NETWORKS_BY_KEY.clear();
+            return closed;
+        });
     }
 
     public static Map<String, Network> getNetworks() {
@@ -159,44 +168,41 @@ public static Map<String, Network> getNetworks() {
 
     public static boolean closeScope(String id) {
         Scope scope = Scope.of(id);
-        LOCK.lock();
-        boolean closed = false;
-        Iterator<Map.Entry<Key, GenericContainer<?>>> iterator = CONTAINERS_BY_KEY.entrySet().iterator();
-        while (iterator.hasNext()) {
-            Map.Entry<Key, GenericContainer<?>> entry = iterator.next();
-            var existingScope = entry.getKey().scope;
-            if (scope.includes(existingScope)) {
-                iterator.remove();
-                GenericContainer<?> container = entry.getValue();
-                LOGGER.debug("Stopping container {}", container.getContainerId());
-                container.close();
-                closed = true;
-                for (Set<GenericContainer<?>> value : CONTAINERS_BY_PROPERTY.values()) {
-                    value.remove(container);
+        return withLock("closeScope", () -> {
+            boolean closed = false;
+            Iterator<Map.Entry<Key, GenericContainer<?>>> iterator = CONTAINERS_BY_KEY.entrySet().iterator();
+            while (iterator.hasNext()) {
+                Map.Entry<Key, GenericContainer<?>> entry = iterator.next();
+                var existingScope = entry.getKey().scope;
+                if (scope.includes(existingScope)) {
+                    iterator.remove();
+                    GenericContainer<?> container = entry.getValue();
+                    LOGGER.debug("Stopping container {}", container.getContainerId());
+                    container.close();
+                    closed = true;
+                    for (Set<GenericContainer<?>> value : CONTAINERS_BY_PROPERTY.values()) {
+                        value.remove(container);
+                    }
                 }
             }
-        }
-        LOCK.unlock();
-        return closed;
+            return closed;
+        });
     }
 
     public static List<GenericContainer<?>> findByRequestedProperty(Scope scope, String property) {
-        LOCK.lock();
-        try {
+        return withLock("findByRequestedProperty", () -> {
             Set<GenericContainer<?>> byProperty = CONTAINERS_BY_PROPERTY.getOrDefault(property, Collections.emptySet());
             LOGGER.debug("Found {} containers for property {}. All properties: {}", byProperty.size(), property, CONTAINERS_BY_PROPERTY.keySet());
             return filterByScope(scope, byProperty);
-        } finally {
-            LOCK.unlock();
-        }
+        });
     }
 
     private static final class Key {
         private final Class<?> type;
         private final String name;
-        private final Scope scope;
         private final Map<String, String> properties;
         private final int hashCode;
+        final Scope scope;
 
         private Key(Class<?> type, String name, Scope scope, Map<String, String> properties) {
             this.type = type;