Prefer adaptive replica selection over awareness attribute based routing

server/src/main/java/org/opensearch/cluster/routing/OperationRouting.java

@@ -38,7 +38,6 @@
 import org.opensearch.cluster.routing.allocation.decider.AwarenessAllocationDecider;
 import org.opensearch.common.Nullable;
 import org.opensearch.common.Strings;
-import org.opensearch.common.logging.DeprecationLogger;
 import org.opensearch.common.settings.ClusterSettings;
 import org.opensearch.common.settings.Setting;
 import org.opensearch.common.settings.Settings;
@@ -55,8 +54,6 @@
 import java.util.Set;
 import java.util.stream.Collectors;
 
-import static org.opensearch.common.Booleans.parseBoolean;
-
 public class OperationRouting {
 
     public static final Setting<Boolean> USE_ADAPTIVE_REPLICA_SELECTION_SETTING = Setting.boolSetting(
@@ -66,53 +63,52 @@ public class OperationRouting {
         Setting.Property.NodeScope
     );
 
-    private static final DeprecationLogger deprecationLogger = DeprecationLogger.getLogger(OperationRouting.class);
-    private static final String IGNORE_AWARENESS_ATTRIBUTES_PROPERTY = "opensearch.search.ignore_awareness_attributes";
-    static final String IGNORE_AWARENESS_ATTRIBUTES_DEPRECATION_MESSAGE =
-        "searches will not be routed based on awareness attributes starting in version 8.0.0; "
-            + "to opt into this behaviour now please set the system property ["
-            + IGNORE_AWARENESS_ATTRIBUTES_PROPERTY
-            + "] to [true]";
-
-    private List<String> awarenessAttributes;
-    private boolean useAdaptiveReplicaSelection;
+    public static final String IGNORE_AWARENESS_ATTRIBUTES = "cluster.search.ignore_awareness_attributes";
+    public static final Setting<Boolean> IGNORE_AWARENESS_ATTRIBUTES_SETTING = Setting.boolSetting(
+        IGNORE_AWARENESS_ATTRIBUTES,
+        true,
+        Setting.Property.Dynamic,
+        Setting.Property.NodeScope
+    );
+    private volatile List<String> awarenessAttributes;
+    private volatile boolean useAdaptiveReplicaSelection;
+    private volatile boolean ignoreAwarenessAttr;
 
     public OperationRouting(Settings settings, ClusterSettings clusterSettings) {
         // whether to ignore awareness attributes when routing requests
-        boolean ignoreAwarenessAttr = parseBoolean(System.getProperty(IGNORE_AWARENESS_ATTRIBUTES_PROPERTY), false);
-        if (ignoreAwarenessAttr == false) {
-            awarenessAttributes = AwarenessAllocationDecider.CLUSTER_ROUTING_ALLOCATION_AWARENESS_ATTRIBUTE_SETTING.get(settings);
-            if (awarenessAttributes.isEmpty() == false) {
-                deprecationLogger.deprecate("searches_not_routed_on_awareness_attributes", IGNORE_AWARENESS_ATTRIBUTES_DEPRECATION_MESSAGE);
-            }
-            clusterSettings.addSettingsUpdateConsumer(
-                AwarenessAllocationDecider.CLUSTER_ROUTING_ALLOCATION_AWARENESS_ATTRIBUTE_SETTING,
-                this::setAwarenessAttributes
-            );
-        } else {
-            awarenessAttributes = Collections.emptyList();
-        }
-
+        this.ignoreAwarenessAttr = clusterSettings.get(IGNORE_AWARENESS_ATTRIBUTES_SETTING);
+        this.awarenessAttributes = AwarenessAllocationDecider.CLUSTER_ROUTING_ALLOCATION_AWARENESS_ATTRIBUTE_SETTING.get(settings);
+        clusterSettings.addSettingsUpdateConsumer(
+            AwarenessAllocationDecider.CLUSTER_ROUTING_ALLOCATION_AWARENESS_ATTRIBUTE_SETTING,
+            this::setAwarenessAttributes
+        );
         this.useAdaptiveReplicaSelection = USE_ADAPTIVE_REPLICA_SELECTION_SETTING.get(settings);
         clusterSettings.addSettingsUpdateConsumer(USE_ADAPTIVE_REPLICA_SELECTION_SETTING, this::setUseAdaptiveReplicaSelection);
+        clusterSettings.addSettingsUpdateConsumer(IGNORE_AWARENESS_ATTRIBUTES_SETTING, this::setIgnoreAwarenessAttributes);
     }
 
     void setUseAdaptiveReplicaSelection(boolean useAdaptiveReplicaSelection) {
         this.useAdaptiveReplicaSelection = useAdaptiveReplicaSelection;
     }
 
+    void setIgnoreAwarenessAttributes(boolean ignoreAwarenessAttributes) {
+        this.ignoreAwarenessAttr = ignoreAwarenessAttributes;
+    }
+
+    public boolean isIgnoreAwarenessAttr() {
+        return ignoreAwarenessAttr;
+    }
+
     List<String> getAwarenessAttributes() {
         return awarenessAttributes;
     }
 
     private void setAwarenessAttributes(List<String> awarenessAttributes) {
-        boolean ignoreAwarenessAttr = parseBoolean(System.getProperty(IGNORE_AWARENESS_ATTRIBUTES_PROPERTY), false);
-        if (ignoreAwarenessAttr == false) {
-            if (this.awarenessAttributes.isEmpty() && awarenessAttributes.isEmpty() == false) {
-                deprecationLogger.deprecate("searches_not_routed_on_awareness_attributes", IGNORE_AWARENESS_ATTRIBUTES_DEPRECATION_MESSAGE);
-            }
-            this.awarenessAttributes = awarenessAttributes;
-        }
+        this.awarenessAttributes = awarenessAttributes;
+    }
+
+    public boolean ignoreAwarenessAttributes() {
+        return this.awarenessAttributes.isEmpty() || this.ignoreAwarenessAttr;
     }
 
     public ShardIterator indexShards(ClusterState clusterState, String index, String id, @Nullable String routing) {
@@ -286,8 +282,7 @@ private ShardIterator preferenceActiveShardIterator(
         // for a different element in the list by also incorporating the
         // shard ID into the hash of the user-supplied preference key.
         routingHash = 31 * routingHash + indexShard.shardId.hashCode();
-
-        if (awarenessAttributes.isEmpty()) {
+        if (ignoreAwarenessAttributes()) {
             return indexShard.activeInitializingShardsIt(routingHash);
         } else {
             return indexShard.preferAttributesActiveInitializingShardsIt(awarenessAttributes, nodes, routingHash);
@@ -300,7 +295,7 @@ private ShardIterator shardRoutings(
         @Nullable ResponseCollectorService collectorService,
         @Nullable Map<String, Long> nodeCounts
     ) {
-        if (awarenessAttributes.isEmpty()) {
+        if (ignoreAwarenessAttributes()) {
             if (useAdaptiveReplicaSelection) {
                 return indexShard.activeInitializingShardsRankedIt(collectorService, nodeCounts);
             } else {

server/src/main/java/org/opensearch/common/settings/ClusterSettings.java

@@ -518,6 +518,7 @@ public void apply(Settings value, Settings current, Settings previous) {
                 FastVectorHighlighter.SETTING_TV_HIGHLIGHT_MULTI_VALUE,
                 Node.BREAKER_TYPE_KEY,
                 OperationRouting.USE_ADAPTIVE_REPLICA_SELECTION_SETTING,
+                OperationRouting.IGNORE_AWARENESS_ATTRIBUTES_SETTING,
                 IndexGraveyard.SETTING_MAX_TOMBSTONES,
                 PersistentTasksClusterService.CLUSTER_TASKS_ALLOCATION_RECHECK_INTERVAL_SETTING,
                 EnableAssignmentDecider.CLUSTER_TASKS_ALLOCATION_ENABLE_SETTING,

server/src/test/java/org/opensearch/cluster/routing/OperationRoutingAwarenessTests.java

@@ -0,0 +1,63 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.cluster.routing;
+
+import org.junit.After;
+import org.opensearch.common.settings.Settings;
+import org.opensearch.test.OpenSearchIntegTestCase;
+
+import static org.hamcrest.Matchers.equalTo;
+import static org.opensearch.cluster.routing.OperationRouting.IGNORE_AWARENESS_ATTRIBUTES;
+import static org.opensearch.test.hamcrest.OpenSearchAssertions.assertAcked;
+
+public class OperationRoutingAwarenessTests extends OpenSearchIntegTestCase {
+
+    @After
+    public void cleanup() {
+        assertAcked(client().admin().cluster().prepareUpdateSettings().setTransientSettings(Settings.builder().putNull("*")));
+    }
+
+    public void testToggleSearchAllocationAwareness() {
+        OperationRouting routing = internalCluster().clusterService().operationRouting();
+
+        // Update awareness settings
+        client().admin()
+            .cluster()
+            .prepareUpdateSettings()
+            .setTransientSettings(Settings.builder().put("cluster.routing.allocation.awareness.attributes", "zone"))
+            .get();
+        assertThat(routing.getAwarenessAttributes().size(), equalTo(1));
+        assertThat(routing.getAwarenessAttributes().get(0), equalTo("zone"));
+        assertTrue(internalCluster().clusterService().operationRouting().ignoreAwarenessAttributes());
+
+        // Unset ignore awareness attributes
+        client().admin()
+            .cluster()
+            .prepareUpdateSettings()
+            .setTransientSettings(Settings.builder().put(IGNORE_AWARENESS_ATTRIBUTES, false))
+            .get();
+        // assert that awareness attributes hasn't changed
+        assertThat(routing.getAwarenessAttributes().size(), equalTo(1));
+        assertThat(routing.getAwarenessAttributes().get(0), equalTo("zone"));
+        assertFalse(internalCluster().clusterService().operationRouting().isIgnoreAwarenessAttr());
+        assertFalse(internalCluster().clusterService().operationRouting().ignoreAwarenessAttributes());
+
+        // Set ignore awareness attributes to true
+        client().admin()
+            .cluster()
+            .prepareUpdateSettings()
+            .setTransientSettings(Settings.builder().put(IGNORE_AWARENESS_ATTRIBUTES, true))
+            .get();
+        // assert that awareness attributes hasn't changed
+        assertThat(routing.getAwarenessAttributes().size(), equalTo(1));
+        assertThat(routing.getAwarenessAttributes().get(0), equalTo("zone"));
+        assertTrue(routing.isIgnoreAwarenessAttr());
+        assertTrue(internalCluster().clusterService().operationRouting().ignoreAwarenessAttributes());
+    }
+}