Remove QueryCachingPolicy#ALWAYS_CACHE (#31451)

The QueryCachingPolicy#ALWAYS_CACHE was deprecated in Lucene-7.4 and
will be removed in Lucene-8.0. This change replaces it with QueryCachingPolicy.
This also makes INDEX_QUERY_CACHE_EVERYTHING_SETTING visible in testing only.

Author: dnhatn

server/src/main/java/org/elasticsearch/common/settings/IndexScopedSettings.java

@@ -151,7 +151,6 @@ public final class IndexScopedSettings extends AbstractScopedSettings {
         IndexModule.INDEX_STORE_TYPE_SETTING,
         IndexModule.INDEX_STORE_PRE_LOAD_SETTING,
         IndexModule.INDEX_QUERY_CACHE_ENABLED_SETTING,
-        IndexModule.INDEX_QUERY_CACHE_EVERYTHING_SETTING,
         FsDirectoryService.INDEX_LOCK_FACTOR_SETTING,
         EngineConfig.INDEX_CODEC_SETTING,
         EngineConfig.INDEX_OPTIMIZE_AUTO_GENERATED_IDS,

server/src/main/java/org/elasticsearch/index/shard/IndexShard.java

@@ -29,6 +29,7 @@
 import org.apache.lucene.index.SegmentInfos;
 import org.apache.lucene.index.SegmentReader;
 import org.apache.lucene.index.Term;
+import org.apache.lucene.search.Query;
 import org.apache.lucene.search.QueryCachingPolicy;
 import org.apache.lucene.search.ReferenceManager;
 import org.apache.lucene.search.Sort;
@@ -299,7 +300,16 @@ public IndexShard(
         // the query cache is a node-level thing, however we want the most popular filters
         // to be computed on a per-shard basis
         if (IndexModule.INDEX_QUERY_CACHE_EVERYTHING_SETTING.get(settings)) {
-            cachingPolicy = QueryCachingPolicy.ALWAYS_CACHE;
+            cachingPolicy = new QueryCachingPolicy() {
+                @Override
+                public void onUse(Query query) {
+
+                }
+                @Override
+                public boolean shouldCache(Query query) {
+                    return true;
+                }
+            };
         } else {
             cachingPolicy = new UsageTrackingQueryCachingPolicy();
         }

server/src/test/java/org/elasticsearch/indices/IndicesQueryCacheTests.java

@@ -89,6 +89,19 @@ public boolean isCacheable(LeafReaderContext ctx) {
 
     }
 
+    private static QueryCachingPolicy alwaysCachePolicy() {
+        return new QueryCachingPolicy() {
+            @Override
+            public void onUse(Query query) {
+
+            }
+            @Override
+            public boolean shouldCache(Query query) {
+                return true;
+            }
+        };
+    }
+
     public void testBasics() throws IOException {
         Directory dir = newDirectory();
         IndexWriter w = new IndexWriter(dir, newIndexWriterConfig());
@@ -98,7 +111,7 @@ public void testBasics() throws IOException {
         ShardId shard = new ShardId("index", "_na_", 0);
         r = ElasticsearchDirectoryReader.wrap(r, shard);
         IndexSearcher s = new IndexSearcher(r);
-        s.setQueryCachingPolicy(QueryCachingPolicy.ALWAYS_CACHE);
+        s.setQueryCachingPolicy(alwaysCachePolicy());
 
         Settings settings = Settings.builder()
                 .put(IndicesQueryCache.INDICES_CACHE_QUERY_COUNT_SETTING.getKey(), 10)
@@ -169,7 +182,7 @@ public void testTwoShards() throws IOException {
         ShardId shard1 = new ShardId("index", "_na_", 0);
         r1 = ElasticsearchDirectoryReader.wrap(r1, shard1);
         IndexSearcher s1 = new IndexSearcher(r1);
-        s1.setQueryCachingPolicy(QueryCachingPolicy.ALWAYS_CACHE);
+        s1.setQueryCachingPolicy(alwaysCachePolicy());
 
         Directory dir2 = newDirectory();
         IndexWriter w2 = new IndexWriter(dir2, newIndexWriterConfig());
@@ -179,7 +192,7 @@ public void testTwoShards() throws IOException {
         ShardId shard2 = new ShardId("index", "_na_", 1);
         r2 = ElasticsearchDirectoryReader.wrap(r2, shard2);
         IndexSearcher s2 = new IndexSearcher(r2);
-        s2.setQueryCachingPolicy(QueryCachingPolicy.ALWAYS_CACHE);
+        s2.setQueryCachingPolicy(alwaysCachePolicy());
 
         Settings settings = Settings.builder()
                 .put(IndicesQueryCache.INDICES_CACHE_QUERY_COUNT_SETTING.getKey(), 10)
@@ -295,7 +308,7 @@ public void testStatsOnEviction() throws IOException {
         ShardId shard1 = new ShardId("index", "_na_", 0);
         r1 = ElasticsearchDirectoryReader.wrap(r1, shard1);
         IndexSearcher s1 = new IndexSearcher(r1);
-        s1.setQueryCachingPolicy(QueryCachingPolicy.ALWAYS_CACHE);
+        s1.setQueryCachingPolicy(alwaysCachePolicy());
 
         Directory dir2 = newDirectory();
         IndexWriter w2 = new IndexWriter(dir2, newIndexWriterConfig());
@@ -305,7 +318,7 @@ public void testStatsOnEviction() throws IOException {
         ShardId shard2 = new ShardId("index", "_na_", 1);
         r2 = ElasticsearchDirectoryReader.wrap(r2, shard2);
         IndexSearcher s2 = new IndexSearcher(r2);
-        s2.setQueryCachingPolicy(QueryCachingPolicy.ALWAYS_CACHE);
+        s2.setQueryCachingPolicy(alwaysCachePolicy());
 
         Settings settings = Settings.builder()
                 .put(IndicesQueryCache.INDICES_CACHE_QUERY_COUNT_SETTING.getKey(), 10)

server/src/test/java/org/elasticsearch/search/scriptfilter/ScriptQuerySearchIT.java

@@ -31,8 +31,10 @@
 import org.elasticsearch.script.ScriptType;
 import org.elasticsearch.search.sort.SortOrder;
 import org.elasticsearch.test.ESIntegTestCase;
+import org.elasticsearch.test.InternalSettingsPlugin;
 
 import java.io.IOException;
+import java.util.Arrays;
 import java.util.Base64;
 import java.util.Collection;
 import java.util.Collections;
@@ -52,7 +54,7 @@ public class ScriptQuerySearchIT extends ESIntegTestCase {
 
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
-        return Collections.singleton(CustomScriptPlugin.class);
+        return Arrays.asList(CustomScriptPlugin.class, InternalSettingsPlugin.class);
     }
 
     public static class CustomScriptPlugin extends MockScriptPlugin {

test/framework/src/main/java/org/elasticsearch/test/ESIntegTestCase.java

@@ -434,10 +434,6 @@ public void randomIndexTemplate() throws IOException {
             if (randomBoolean()) {
                 randomSettingsBuilder.put(IndexModule.INDEX_QUERY_CACHE_ENABLED_SETTING.getKey(), randomBoolean());
             }
-
-            if (randomBoolean()) {
-                randomSettingsBuilder.put(IndexModule.INDEX_QUERY_CACHE_EVERYTHING_SETTING.getKey(), randomBoolean());
-            }
             PutIndexTemplateRequestBuilder putTemplate = client().admin().indices()
                 .preparePutTemplate("random_index_template")
                 .setPatterns(Collections.singletonList("*"))

test/framework/src/main/java/org/elasticsearch/test/InternalSettingsPlugin.java

@@ -22,6 +22,7 @@
 import org.elasticsearch.common.settings.Setting;
 import org.elasticsearch.common.settings.Setting.Property;
 import org.elasticsearch.common.unit.TimeValue;
+import org.elasticsearch.index.IndexModule;
 import org.elasticsearch.index.IndexService;
 import org.elasticsearch.plugins.Plugin;
 
@@ -51,6 +52,8 @@ public List<Setting<?>> getSettings() {
                 INDEX_CREATION_DATE_SETTING,
                 PROVIDED_NAME_SETTING,
                 TRANSLOG_RETENTION_CHECK_INTERVAL_SETTING,
-                IndexService.GLOBAL_CHECKPOINT_SYNC_INTERVAL_SETTING);
+                IndexService.GLOBAL_CHECKPOINT_SYNC_INTERVAL_SETTING,
+                IndexModule.INDEX_QUERY_CACHE_EVERYTHING_SETTING
+            );
     }
 }

x-pack/plugin/security/src/test/java/org/elasticsearch/test/SecuritySettingsSource.java

@@ -169,7 +169,8 @@ protected void addDefaultSecurityTransportType(Settings.Builder builder, Setting
 
     @Override
     public Collection<Class<? extends Plugin>> nodePlugins() {
-        return Arrays.asList(LocalStateSecurity.class, Netty4Plugin.class, ReindexPlugin.class, CommonAnalysisPlugin.class);
+        return Arrays.asList(LocalStateSecurity.class, Netty4Plugin.class, ReindexPlugin.class, CommonAnalysisPlugin.class,
+            InternalSettingsPlugin.class);
     }
 
     @Override