Fix bitset filter cache loading in Stateless

As recognized in PR elastic#113478 reviewing, the bitset filter cache was wrongly eagerly loaded only for fast refresh indices on index nodes. However, it should be eagerly loaded for any index that can be searched. This PR fixes this.
kingherc · Oct 6, 2024 · c9e4a56 · c9e4a56
1 parent 6535bda
commit c9e4a56
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Showing 2 changed files with 10 additions and 4 deletions.
diff --git a/server/src/main/java/org/elasticsearch/index/cache/bitset/BitsetFilterCache.java b/server/src/main/java/org/elasticsearch/index/cache/bitset/BitsetFilterCache.java
@@ -105,9 +105,14 @@ static boolean shouldLoadRandomAccessFiltersEagerly(IndexSettings settings) {
         boolean loadFiltersEagerlySetting = settings.getValue(INDEX_LOAD_RANDOM_ACCESS_FILTERS_EAGERLY_SETTING);
         boolean isStateless = DiscoveryNode.isStateless(settings.getNodeSettings());
         if (isStateless) {
-            return DiscoveryNode.hasRole(settings.getNodeSettings(), DiscoveryNodeRole.INDEX_ROLE)
-                && loadFiltersEagerlySetting
-                && INDEX_FAST_REFRESH_SETTING.get(settings.getSettings());
+            // We would like to eagerly load filters when the index can get searched. In Stateless, searches can happen on a search node
+            // for regular non-fast-refresh indices, or on an index node for fast refresh indices.
+            boolean fastRefreshIndex = INDEX_FAST_REFRESH_SETTING.get(settings.getSettings());
+            boolean fastRefreshIndexOnIndexNode = fastRefreshIndex
+                && DiscoveryNode.hasRole(settings.getNodeSettings(), DiscoveryNodeRole.INDEX_ROLE);
+            boolean nonFastRefreshIndexOnSearchNode = (fastRefreshIndex == false)
+                && DiscoveryNode.hasRole(settings.getNodeSettings(), DiscoveryNodeRole.SEARCH_ROLE);
+            return loadFiltersEagerlySetting && (fastRefreshIndexOnIndexNode || nonFastRefreshIndexOnSearchNode);
         } else {
             return loadFiltersEagerlySetting;
         }

diff --git a/server/src/test/java/org/elasticsearch/index/cache/bitset/BitSetFilterCacheTests.java b/server/src/test/java/org/elasticsearch/index/cache/bitset/BitSetFilterCacheTests.java
@@ -276,7 +276,8 @@ public void testShouldLoadRandomAccessFiltersEagerly() {
                     for (var isStateless : values) {
                         if (isStateless) {
                             assertEquals(
-                                loadFiltersEagerly && indexFastRefresh && hasIndexRole,
+                                loadFiltersEagerly
+                                    && ((indexFastRefresh && hasIndexRole) || (indexFastRefresh == false && hasIndexRole == false)),
                                 BitsetFilterCache.shouldLoadRandomAccessFiltersEagerly(
                                     bitsetFilterCacheSettings(isStateless, hasIndexRole, loadFiltersEagerly, indexFastRefresh)
                                 )