Remove Adjacency_matrix setting in favour of Lucene Boolean query clause setting (#46327)

Closes #46324

docs/reference/aggregations/bucket/adjacency-matrix-aggregation.asciidoc

@@ -108,5 +108,7 @@ additional levels of data required to perform https://en.wikipedia.org/wiki/Dyna
 where examining interactions _over time_ becomes important.
 
 ==== Limitations
-For N filters the matrix of buckets produced can be N²/2 and so there is a default maximum 
+For N filters the matrix of buckets produced can be N²/2 which can be costly.
+The circuit breaker settings prevent results producing too many buckets and to avoid excessive disk seeks
+the `indices.query.bool.max_clause_count` setting is used to limit the number of filters. 
 imposed of 100 filters . This setting can be changed using the `index.max_adjacency_matrix_filters` index-level setting.

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

@@ -117,7 +117,6 @@ public final class IndexScopedSettings extends AbstractScopedSettings {
             IndexSettings.MAX_NGRAM_DIFF_SETTING,
             IndexSettings.MAX_SHINGLE_DIFF_SETTING,
             IndexSettings.MAX_RESCORE_WINDOW_SETTING,
-            IndexSettings.MAX_ADJACENCY_MATRIX_FILTERS_SETTING,
             IndexSettings.MAX_ANALYZED_OFFSET_SETTING,
             IndexSettings.MAX_TERMS_COUNT_SETTING,
             IndexSettings.INDEX_TRANSLOG_SYNC_INTERVAL_SETTING,

server/src/main/java/org/elasticsearch/index/IndexSettings.java

@@ -173,13 +173,6 @@ public final class IndexSettings {
     public static final Setting<Integer> MAX_RESCORE_WINDOW_SETTING =
             Setting.intSetting("index.max_rescore_window", MAX_RESULT_WINDOW_SETTING, 1,
                 Property.Dynamic, Property.IndexScope);
-    /**
-     * Index setting describing the maximum number of filters clauses that can be used
-     * in an adjacency_matrix aggregation. The max number of buckets produced by
-     * N filters is (N*N)/2 so a limit of 100 filters is imposed by default.
-     */
-    public static final Setting<Integer> MAX_ADJACENCY_MATRIX_FILTERS_SETTING =
-        Setting.intSetting("index.max_adjacency_matrix_filters", 100, 2, Property.Dynamic, Property.IndexScope);
     public static final TimeValue DEFAULT_REFRESH_INTERVAL = new TimeValue(1, TimeUnit.SECONDS);
     public static final Setting<TimeValue> INDEX_REFRESH_INTERVAL_SETTING =
         Setting.timeSetting("index.refresh_interval", DEFAULT_REFRESH_INTERVAL, new TimeValue(-1, TimeUnit.MILLISECONDS),
@@ -373,7 +366,6 @@ public final class IndexSettings {
     private volatile boolean warmerEnabled;
     private volatile int maxResultWindow;
     private volatile int maxInnerResultWindow;
-    private volatile int maxAdjacencyMatrixFilters;
     private volatile int maxRescoreWindow;
     private volatile int maxDocvalueFields;
     private volatile int maxScriptFields;
@@ -488,7 +480,6 @@ public final class IndexSettings {
         warmerEnabled = scopedSettings.get(INDEX_WARMER_ENABLED_SETTING);
         maxResultWindow = scopedSettings.get(MAX_RESULT_WINDOW_SETTING);
         maxInnerResultWindow = scopedSettings.get(MAX_INNER_RESULT_WINDOW_SETTING);
-        maxAdjacencyMatrixFilters = scopedSettings.get(MAX_ADJACENCY_MATRIX_FILTERS_SETTING);
         maxRescoreWindow = scopedSettings.get(MAX_RESCORE_WINDOW_SETTING);
         maxDocvalueFields = scopedSettings.get(MAX_DOCVALUE_FIELDS_SEARCH_SETTING);
         maxScriptFields = scopedSettings.get(MAX_SCRIPT_FIELDS_SETTING);
@@ -530,7 +521,6 @@ public final class IndexSettings {
         scopedSettings.addSettingsUpdateConsumer(INDEX_TRANSLOG_SYNC_INTERVAL_SETTING, this::setTranslogSyncInterval);
         scopedSettings.addSettingsUpdateConsumer(MAX_RESULT_WINDOW_SETTING, this::setMaxResultWindow);
         scopedSettings.addSettingsUpdateConsumer(MAX_INNER_RESULT_WINDOW_SETTING, this::setMaxInnerResultWindow);
-        scopedSettings.addSettingsUpdateConsumer(MAX_ADJACENCY_MATRIX_FILTERS_SETTING, this::setMaxAdjacencyMatrixFilters);
         scopedSettings.addSettingsUpdateConsumer(MAX_RESCORE_WINDOW_SETTING, this::setMaxRescoreWindow);
         scopedSettings.addSettingsUpdateConsumer(MAX_DOCVALUE_FIELDS_SEARCH_SETTING, this::setMaxDocvalueFields);
         scopedSettings.addSettingsUpdateConsumer(MAX_SCRIPT_FIELDS_SETTING, this::setMaxScriptFields);
@@ -821,17 +811,6 @@ public final class IndexSettings {
         this.maxInnerResultWindow = maxInnerResultWindow;
     }
 
-    /**
-     * Returns the max number of filters in adjacency_matrix aggregation search requests
-     */
-    public int getMaxAdjacencyMatrixFilters() {
-        return this.maxAdjacencyMatrixFilters;
-    }
-
-    private void setMaxAdjacencyMatrixFilters(int maxAdjacencyFilters) {
-        this.maxAdjacencyMatrixFilters = maxAdjacencyFilters;
-    }
-
     /**
      * Returns the maximum rescore window for search requests.
      */

server/src/main/java/org/elasticsearch/search/aggregations/bucket/adjacency/AdjacencyMatrixAggregationBuilder.java

@@ -19,16 +19,17 @@
 
 package org.elasticsearch.search.aggregations.bucket.adjacency;
 
+import org.apache.lucene.search.BooleanQuery;
 import org.elasticsearch.common.ParseField;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.xcontent.ObjectParser;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentParser;
-import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.query.QueryBuilder;
 import org.elasticsearch.index.query.QueryShardContext;
 import org.elasticsearch.index.query.Rewriteable;
+import org.elasticsearch.search.SearchModule;
 import org.elasticsearch.search.aggregations.AbstractAggregationBuilder;
 import org.elasticsearch.search.aggregations.AggregationBuilder;
 import org.elasticsearch.search.aggregations.AggregatorFactories.Builder;
@@ -198,13 +199,13 @@ public class AdjacencyMatrixAggregationBuilder extends AbstractAggregationBuilde
     @Override
     protected AggregatorFactory doBuild(QueryShardContext queryShardContext, AggregatorFactory parent, Builder subFactoriesBuilder)
             throws IOException {
-        int maxFilters = queryShardContext.getIndexSettings().getMaxAdjacencyMatrixFilters();
+        int maxFilters = BooleanQuery.getMaxClauseCount();
         if (filters.size() > maxFilters){
             throw new IllegalArgumentException(
                     "Number of filters is too large, must be less than or equal to: [" + maxFilters + "] but was ["
                             + filters.size() + "]."
-                            + "This limit can be set by changing the [" + IndexSettings.MAX_ADJACENCY_MATRIX_FILTERS_SETTING.getKey()
-                            + "] index level setting.");
+                            + "This limit can be set by changing the [" + SearchModule.INDICES_MAX_CLAUSE_COUNT_SETTING.getKey()
+                            + "] setting.");
         }
 
         List<KeyedFilter> rewrittenFilters = new ArrayList<>(filters.size());

server/src/test/java/org/elasticsearch/index/IndexSettingsTests.java

@@ -344,29 +344,6 @@ public class IndexSettingsTests extends ESTestCase {
         assertEquals(IndexSettings.MAX_SCRIPT_FIELDS_SETTING.get(Settings.EMPTY).intValue(), settings.getMaxScriptFields());
     }
 
-    public void testMaxAdjacencyMatrixFiltersSetting() {
-        IndexMetaData metaData = newIndexMeta("index", Settings.builder()
-            .put(IndexMetaData.SETTING_VERSION_CREATED, Version.CURRENT)
-            .put(IndexSettings.MAX_ADJACENCY_MATRIX_FILTERS_SETTING.getKey(), 15)
-            .build());
-        IndexSettings settings = new IndexSettings(metaData, Settings.EMPTY);
-        assertEquals(15, settings.getMaxAdjacencyMatrixFilters());
-        settings.updateIndexMetaData(newIndexMeta("index",
-            Settings.builder().put(IndexSettings.MAX_ADJACENCY_MATRIX_FILTERS_SETTING.getKey(),
-            42).build()));
-        assertEquals(42, settings.getMaxAdjacencyMatrixFilters());
-        settings.updateIndexMetaData(newIndexMeta("index", Settings.EMPTY));
-        assertEquals(IndexSettings.MAX_ADJACENCY_MATRIX_FILTERS_SETTING.get(Settings.EMPTY).intValue(),
-                settings.getMaxAdjacencyMatrixFilters());
-
-        metaData = newIndexMeta("index", Settings.builder()
-            .put(IndexMetaData.SETTING_VERSION_CREATED, Version.CURRENT)
-            .build());
-        settings = new IndexSettings(metaData, Settings.EMPTY);
-        assertEquals(IndexSettings.MAX_ADJACENCY_MATRIX_FILTERS_SETTING.get(Settings.EMPTY).intValue(),
-                settings.getMaxAdjacencyMatrixFilters());
-    }
-
     public void testMaxRegexLengthSetting() {
         IndexMetaData metaData = newIndexMeta("index", Settings.builder()
             .put(IndexMetaData.SETTING_VERSION_CREATED, Version.CURRENT)

server/src/test/java/org/elasticsearch/search/aggregations/bucket/AdjacencyMatrixIT.java

@@ -25,9 +25,9 @@ import org.elasticsearch.action.search.SearchPhaseExecutionException;
 import org.elasticsearch.action.search.SearchResponse;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.xcontent.XContentBuilder;
-import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.query.BoolQueryBuilder;
 import org.elasticsearch.index.query.QueryBuilder;
+import org.elasticsearch.search.SearchModule;
 import org.elasticsearch.search.aggregations.InternalAggregation;
 import org.elasticsearch.search.aggregations.bucket.adjacency.AdjacencyMatrix;
 import org.elasticsearch.search.aggregations.bucket.adjacency.AdjacencyMatrix.Bucket;
@@ -46,7 +46,6 @@ import static org.elasticsearch.index.query.QueryBuilders.termQuery;
 import static org.elasticsearch.search.aggregations.AggregationBuilders.adjacencyMatrix;
 import static org.elasticsearch.search.aggregations.AggregationBuilders.avg;
 import static org.elasticsearch.search.aggregations.AggregationBuilders.histogram;
-import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertAcked;
 import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertSearchResponse;
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.equalTo;
@@ -58,16 +57,11 @@ import static org.hamcrest.core.IsNull.notNullValue;
 public class AdjacencyMatrixIT extends ESIntegTestCase {
 
     static int numDocs, numSingleTag1Docs, numSingleTag2Docs, numTag1Docs, numTag2Docs, numMultiTagDocs;
-    static final int MAX_NUM_FILTERS = 3;
 
     @Override
     public void setupSuiteScopeCluster() throws Exception {
         createIndex("idx");
         createIndex("idx2");
-        assertAcked(client().admin().indices().prepareUpdateSettings("idx")
-                .setSettings(
-                        Settings.builder().put(IndexSettings.MAX_ADJACENCY_MATRIX_FILTERS_SETTING.getKey(), MAX_NUM_FILTERS))
-                .get());
 
         numDocs = randomIntBetween(5, 20);
         numTag1Docs = randomIntBetween(1, numDocs - 1);
@@ -300,9 +294,10 @@ public class AdjacencyMatrixIT extends ESIntegTestCase {
 
     public void testTooLargeMatrix() throws Exception{
 
-        // Create more filters than is permitted by index settings.
+        // Create more filters than is permitted by Lucene Bool clause settings.
         MapBuilder filtersMap = new MapBuilder();
-        for (int i = 0; i <= MAX_NUM_FILTERS; i++) {
+        int maxFilters = SearchModule.INDICES_MAX_CLAUSE_COUNT_SETTING.get(Settings.EMPTY);
+        for (int i = 0; i <= maxFilters; i++) {
             filtersMap.add("tag" + i, termQuery("tag", "tag" + i));
         }
 

server/src/test/java/org/elasticsearch/search/aggregations/bucket/adjacency/AdjacencyMatrixAggregationBuilderTests.java

@@ -26,6 +26,7 @@ import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.query.QueryBuilder;
 import org.elasticsearch.index.query.QueryShardContext;
 import org.elasticsearch.index.shard.IndexShard;
+import org.elasticsearch.search.SearchModule;
 import org.elasticsearch.search.aggregations.AggregatorFactories;
 import org.elasticsearch.search.aggregations.AggregatorFactory;
 import org.elasticsearch.search.internal.SearchContext;
@@ -48,7 +49,6 @@ public class AdjacencyMatrixAggregationBuilderTests extends ESTestCase {
         QueryShardContext queryShardContext = mock(QueryShardContext.class);
         IndexShard indexShard = mock(IndexShard.class);
         Settings settings = Settings.builder()
-            .put("index.max_adjacency_matrix_filters", 2)
             .put(IndexMetaData.SETTING_VERSION_CREATED, Version.CURRENT)
             .put(IndexMetaData.SETTING_NUMBER_OF_REPLICAS, 1)
             .put(IndexMetaData.SETTING_NUMBER_OF_SHARDS, 2)
@@ -58,9 +58,13 @@ public class AdjacencyMatrixAggregationBuilderTests extends ESTestCase {
         when(indexShard.indexSettings()).thenReturn(indexSettings);
         when(queryShardContext.getIndexSettings()).thenReturn(indexSettings);
         SearchContext context = new TestSearchContext(queryShardContext, indexShard);
+        
+        int maxFilters = SearchModule.INDICES_MAX_CLAUSE_COUNT_SETTING.get(context.indexShard().indexSettings().getSettings());
+        int maxFiltersPlusOne = maxFilters + 1;
+        
 
-        Map<String, QueryBuilder> filters = new HashMap<>(3);
-        for (int i = 0; i < 3; i++) {
+        Map<String, QueryBuilder> filters = new HashMap<>(maxFilters);
+        for (int i = 0; i < maxFiltersPlusOne; i++) {
             QueryBuilder queryBuilder = mock(QueryBuilder.class);
             // return builder itself to skip rewrite
             when(queryBuilder.rewrite(queryShardContext)).thenReturn(queryBuilder);
@@ -69,9 +73,10 @@ public class AdjacencyMatrixAggregationBuilderTests extends ESTestCase {
         AdjacencyMatrixAggregationBuilder builder = new AdjacencyMatrixAggregationBuilder("dummy", filters);
         IllegalArgumentException ex = expectThrows(IllegalArgumentException.class,
             () -> builder.doBuild(context.getQueryShardContext(), null, new AggregatorFactories.Builder()));
-        assertThat(ex.getMessage(), equalTo("Number of filters is too large, must be less than or equal to: [2] but was [3]."
-            + "This limit can be set by changing the [" + IndexSettings.MAX_ADJACENCY_MATRIX_FILTERS_SETTING.getKey()
-            + "] index level setting."));
+        assertThat(ex.getMessage(), equalTo("Number of filters is too large, must be less than or equal to: ["+ maxFilters
+                +"] but was ["+ maxFiltersPlusOne +"]."
+            + "This limit can be set by changing the [" + SearchModule.INDICES_MAX_CLAUSE_COUNT_SETTING.getKey()
+            + "] setting."));
 
         // filter size not grater than max size should return an instance of AdjacencyMatrixAggregatorFactory
         Map<String, QueryBuilder> emptyFilters = Collections.emptyMap();

x-pack/plugin/ccr/src/main/java/org/elasticsearch/xpack/ccr/action/TransportResumeFollowAction.java

@@ -389,7 +389,6 @@ public class TransportResumeFollowAction extends TransportMasterNodeAction<Resum
             IndexSettings.MAX_DOCVALUE_FIELDS_SEARCH_SETTING,
             IndexSettings.MAX_TOKEN_COUNT_SETTING,
             IndexSettings.MAX_SLICES_PER_SCROLL,
-            IndexSettings.MAX_ADJACENCY_MATRIX_FILTERS_SETTING,
             IndexSettings.DEFAULT_PIPELINE,
             IndexSettings.INDEX_SEARCH_THROTTLED,
             IndexSettings.INDEX_TRANSLOG_RETENTION_AGE_SETTING,