Fixes #31878: return 400 for a search against an index OpenMetadata does not manage (backport 2.0 #35516)

openmetadata-integration-tests/src/test/java/org/openmetadata/it/tests/SearchResourceIT.java

@@ -19,6 +19,7 @@
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Locale;
+import java.util.UUID;
 import java.util.concurrent.TimeUnit;
 import org.awaitility.Awaitility;
 import org.junit.jupiter.api.Test;
@@ -2124,4 +2125,28 @@ void testValidQueryFilterStillApplies() throws Exception {
 
     assertEquals(200, response.statusCode(), response.body());
   }
+
+  @ParameterizedTest
+  @ValueSource(
+      strings = {
+        "/v1/search/query?q=*&index=nope_search_index",
+        "/v1/search/query?q=*&index=table_search_index,nope_search_index",
+        "/v1/search/get/nope_search_index/doc/00000000-0000-0000-0000-000000000000"
+      })
+  void testUnknownIndexIsRejectedAsBadRequest(String path) throws Exception {
+    HttpResponse<String> response = httpGetSearch(path);
+
+    assertEquals(400, response.statusCode(), path + " returned " + response.body());
+    assertTrue(
+        response.body().contains("Unknown search index [nope_search_index]"),
+        path + " returned " + response.body());
+  }
+
+  @Test
+  void testMissingDocumentInAKnownIndexIsNotFound() throws Exception {
+    HttpResponse<String> response =
+        httpGetSearch("/v1/search/get/table_search_index/doc/" + UUID.randomUUID());
+
+    assertEquals(404, response.statusCode(), response.body());
+  }
 }

openmetadata-service/src/main/java/org/openmetadata/service/search/SearchEngineErrors.java

@@ -3,6 +3,8 @@
 import jakarta.ws.rs.core.Response;
 import java.util.List;
 import org.openmetadata.sdk.exception.SearchException;
+import org.openmetadata.sdk.exception.SearchIndexNotFoundException;
+import org.openmetadata.service.Entity;
 
 /**
  * Translates a search engine's own HTTP failure into the status OpenMetadata reports to its caller.
@@ -14,13 +16,40 @@
  *
  * <p>Only {@code 400} is re-mapped. Everything else, including the {@code 429} the engine returns
  * when a circuit breaker trips, stays a 500: those are genuinely not the caller's doing.
+ *
+ * <p>A missing index ({@code 404}) depends on whose name it is. A name OpenMetadata does not manage
+ * is the caller's mistake and is a 400. A managed index that is missing from the cluster, for
+ * example after a failed reindex, is an outage and stays a 500. Issue #31878.
  */
 public final class SearchEngineErrors {
 
   private static final int BAD_REQUEST = 400;
 
   private SearchEngineErrors() {}
 
+  /** Classifies a missing index using the names the running server manages. */
+  public static SearchIndexNotFoundException indexNotFound(String resolvedIndex) {
+    SearchRepository searchRepository = Entity.getSearchRepository();
+    List<String> unknownNames =
+        searchRepository == null ? List.of() : searchRepository.unknownIndexNames(resolvedIndex);
+    return indexNotFound(resolvedIndex, unknownNames);
+  }
+
+  /**
+   * @param resolvedIndex the index expression sent to the engine
+   * @param unknownNames the names in it that OpenMetadata does not manage, as the caller typed them
+   */
+  public static SearchIndexNotFoundException indexNotFound(
+      String resolvedIndex, List<String> unknownNames) {
+    if (unknownNames.isEmpty()) {
+      return new SearchIndexNotFoundException(
+          String.format("Failed to find index %s", resolvedIndex));
+    }
+    return SearchIndexNotFoundException.withStatus(
+        Response.Status.BAD_REQUEST,
+        String.format("Unknown search index [%s]", String.join(", ", unknownNames)));
+  }
+
   /**
    * @param upstreamStatus HTTP status the search engine returned
    * @param message the engine's own message

openmetadata-service/src/main/java/org/openmetadata/service/search/SearchIndexUtils.java

@@ -1,5 +1,6 @@
 package org.openmetadata.service.search;
 
+import static org.openmetadata.common.utils.CommonUtil.listOrEmpty;
 import static org.openmetadata.common.utils.CommonUtil.nullOrEmpty;
 import static org.openmetadata.search.IndexMapping.INDEX_NAME_SEPARATOR;
 import static org.openmetadata.service.apps.bundles.insights.search.DataInsightsSearchInterface.getStringWithClusterAlias;
@@ -20,6 +21,7 @@
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
@@ -140,6 +142,66 @@ private static String resolveSingleAliasToken(
     return clusterPrefix == null ? token : clusterPrefix + token;
   }
 
+  /**
+   * Every name, without cluster prefix, that resolves to an index or alias OpenMetadata manages:
+   * entity types, canonical index names and their aliases.
+   */
+  public static Set<String> knownIndexNames(Map<String, IndexMapping> entityIndexMap) {
+    if (entityIndexMap == null) {
+      return Set.of();
+    }
+    Set<String> names = new HashSet<>(entityIndexMap.keySet());
+    entityIndexMap.values().forEach(mapping -> addMappingNames(names, mapping));
+    names.remove(null);
+    return Set.copyOf(names);
+  }
+
+  private static void addMappingNames(Set<String> names, IndexMapping mapping) {
+    names.add(mapping.getIndexName());
+    names.add(mapping.getAlias());
+    names.addAll(listOrEmpty(mapping.getParentAliases()));
+    names.addAll(listOrEmpty(mapping.getChildAliases()));
+    names.addAll(listOrEmpty(mapping.getDataInsightAliases()));
+  }
+
+  /**
+   * Names in an index expression, already resolved by {@link #getIndexOrAliasName}, that
+   * OpenMetadata does not manage, as the caller typed them. Wildcards, exclusions and Data Insights
+   * names never count as unknown. An empty result means every name is managed, so a missing index
+   * is a server fault rather than the caller's mistake.
+   */
+  public static List<String> unknownIndexNames(
+      String resolvedIndex, Set<String> knownIndexNames, String clusterAlias) {
+    if (nullOrEmpty(resolvedIndex) || nullOrEmpty(knownIndexNames)) {
+      return List.of();
+    }
+    return Arrays.stream(resolvedIndex.split(","))
+        .map(String::trim)
+        .filter(token -> isPlainIndexName(token, clusterAlias))
+        .map(token -> withoutClusterPrefix(token, clusterAlias))
+        .filter(name -> !knownIndexNames.contains(name))
+        .distinct()
+        .toList();
+  }
+
+  private static boolean isPlainIndexName(String token, String clusterAlias) {
+    return !token.isEmpty()
+        && !token.contains("*")
+        && !token.startsWith("-")
+        && !token.startsWith(DI_SEARCH_INDEX_PREFIX)
+        && !token.startsWith(getStringWithClusterAlias(clusterAlias, DI_SEARCH_INDEX_PREFIX));
+  }
+
+  private static String withoutClusterPrefix(String token, String clusterAlias) {
+    if (nullOrEmpty(clusterAlias)) {
+      return token;
+    }
+    String prefix = clusterAlias + INDEX_NAME_SEPARATOR;
+    return token.startsWith(prefix) && token.length() > prefix.length()
+        ? token.substring(prefix.length())
+        : token;
+  }
+
   /**
    * Resolves comma-separated entity names, canonical indexes, and {@code all}/{@code dataAsset}
    * aliases to sorted, distinct registered entity types. Unknown or empty targets have no members.

openmetadata-service/src/main/java/org/openmetadata/service/search/SearchRepository.java

@@ -418,6 +418,7 @@ public static void deferOrRunSearchWrite(
 
   @Getter private Map<String, IndexMapping> entityIndexMap;
   private Map<String, IndexMapping> aliasIndexMap;
+  private Set<String> knownIndexNames = Set.of();
 
   /**
    * Staged index names being populated by an in-flight reindex, keyed by the canonical index name
@@ -548,6 +549,7 @@ private void loadIndexMappings() {
     IndexMappingLoader mappingLoader = IndexMappingLoader.getInstance();
     entityIndexMap = mappingLoader.getIndexMapping();
     aliasIndexMap = buildAliasIndexMap(entityIndexMap);
+    knownIndexNames = SearchIndexUtils.knownIndexNames(entityIndexMap);
   }
 
   private static Map<String, IndexMapping> buildAliasIndexMap(
@@ -1005,6 +1007,11 @@ public String getIndexOrAliasName(String name) {
     return SearchIndexUtils.getIndexOrAliasName(name, entityIndexMap, aliasIndexMap, clusterAlias);
   }
 
+  /** @see SearchIndexUtils#unknownIndexNames(String, Set, String) */
+  public List<String> unknownIndexNames(String resolvedIndex) {
+    return SearchIndexUtils.unknownIndexNames(resolvedIndex, knownIndexNames, clusterAlias);
+  }
+
   /** @see SearchIndexUtils#getEntityTypesForIndex(String, Map, Map, String) */
   public List<String> getEntityTypesForIndex(String index) {
     return SearchIndexUtils.getEntityTypesForIndex(

openmetadata-service/src/main/java/org/openmetadata/service/search/elasticsearch/ElasticSearchEntityManager.java

@@ -69,11 +69,11 @@
 import org.openmetadata.schema.type.entityRelationship.NodeInformation;
 import org.openmetadata.schema.utils.JsonUtils;
 import org.openmetadata.sdk.exception.SearchException;
-import org.openmetadata.sdk.exception.SearchIndexNotFoundException;
 import org.openmetadata.search.IndexMapping;
 import org.openmetadata.service.Entity;
 import org.openmetadata.service.search.EntityManagementClient;
 import org.openmetadata.service.search.SearchClient;
+import org.openmetadata.service.search.SearchEngineErrors;
 import org.openmetadata.service.search.SearchIndexRetryQueue;
 import org.openmetadata.service.search.SearchIndexUtils;
 import org.openmetadata.service.search.SearchRetryUtil;
@@ -597,12 +597,9 @@ public Response getDocByID(String indexName, String entityId) throws IOException
       return getResponse(Response.Status.NOT_FOUND, "Document not found.");
     }
 
+    String index = Entity.getSearchRepository().getIndexOrAliasName(indexName);
     try {
-      GetResponse<Map> response =
-          client.get(
-              g ->
-                  g.index(Entity.getSearchRepository().getIndexOrAliasName(indexName)).id(entityId),
-              Map.class);
+      GetResponse<Map> response = client.get(g -> g.index(index).id(entityId), Map.class);
 
       // This path runs no query and has no SubjectContext, so it cannot tell whose restricted
       // memory a document is: a non-org-wide memory reads as not found rather than leaking.
@@ -613,8 +610,7 @@ public Response getDocByID(String indexName, String entityId) throws IOException
       }
     } catch (ElasticsearchException e) {
       if (e.status() == 404) {
-        throw new SearchIndexNotFoundException(
-            String.format("Failed to find doc with id %s", entityId));
+        throw SearchEngineErrors.indexNotFound(index);
       } else {
         throw new SearchException(String.format("Search failed due to %s", e.getMessage()));
       }

openmetadata-service/src/main/java/org/openmetadata/service/search/elasticsearch/ElasticSearchSearchManager.java

@@ -68,7 +68,6 @@
 import org.openmetadata.schema.type.Include;
 import org.openmetadata.schema.utils.JsonUtils;
 import org.openmetadata.sdk.exception.SearchException;
-import org.openmetadata.sdk.exception.SearchIndexNotFoundException;
 import org.openmetadata.service.Entity;
 import org.openmetadata.service.jdbi3.ListFilter;
 import org.openmetadata.service.jdbi3.TableRepository;
@@ -369,7 +368,7 @@ private SearchResultListMapper doListWithOffset(
       return new SearchResultListMapper(results, totalHits);
     } catch (ElasticsearchException e) {
       if (e.status() == 404) {
-        throw new SearchIndexNotFoundException(String.format("Failed to find index %s", index));
+        throw SearchEngineErrors.indexNotFound(index);
       } else {
         throw buildSearchException(e);
       }
@@ -682,7 +681,7 @@ public SearchResultListMapper listWithDeepPagination(
           results, totalHits, lastHitSortValues, lastDocumentsInBatch);
     } catch (ElasticsearchException e) {
       if (e.status() == 404) {
-        throw new SearchIndexNotFoundException(String.format("Failed to find index %s", index));
+        throw SearchEngineErrors.indexNotFound(index);
       } else {
         throw buildSearchException(e);
       }
@@ -1146,8 +1145,7 @@ public Response doSearch(
 
     } catch (ElasticsearchException e) {
       if (e.status() == 404) {
-        throw new SearchIndexNotFoundException(
-            String.format("Failed to find index %s", request.getIndex()));
+        throw SearchEngineErrors.indexNotFound(request.getIndex());
       } else {
         throw buildSearchException(e);
       }
@@ -1334,8 +1332,7 @@ public SearchResultListMapper searchForExport(
       return new SearchResultListMapper(results, totalHits, lastHitSortValues);
     } catch (ElasticsearchException e) {
       if (e.status() == 404) {
-        throw new SearchIndexNotFoundException(
-            String.format("Failed to find index %s", request.getIndex()));
+        throw SearchEngineErrors.indexNotFound(request.getIndex());
       } else {
         throw buildSearchException(e);
       }

openmetadata-service/src/main/java/org/openmetadata/service/search/opensearch/OpenSearchEntityManager.java

@@ -46,11 +46,11 @@
 import org.openmetadata.schema.type.entityRelationship.NodeInformation;
 import org.openmetadata.schema.utils.JsonUtils;
 import org.openmetadata.sdk.exception.SearchException;
-import org.openmetadata.sdk.exception.SearchIndexNotFoundException;
 import org.openmetadata.search.IndexMapping;
 import org.openmetadata.service.Entity;
 import org.openmetadata.service.search.EntityManagementClient;
 import org.openmetadata.service.search.SearchClient;
+import org.openmetadata.service.search.SearchEngineErrors;
 import org.openmetadata.service.search.SearchIndexRetryQueue;
 import org.openmetadata.service.search.SearchIndexUtils;
 import org.openmetadata.service.search.SearchRetryUtil;
@@ -644,12 +644,9 @@ public Response getDocByID(String indexName, String entityId) throws IOException
       return getResponse(Response.Status.NOT_FOUND, "Document not found.");
     }
 
+    String index = Entity.getSearchRepository().getIndexOrAliasName(indexName);
     try {
-      GetResponse<Map> response =
-          client.get(
-              g ->
-                  g.index(Entity.getSearchRepository().getIndexOrAliasName(indexName)).id(entityId),
-              Map.class);
+      GetResponse<Map> response = client.get(g -> g.index(index).id(entityId), Map.class);
 
       // This path runs no query and has no SubjectContext, so it cannot tell whose restricted
       // memory a document is: a non-org-wide memory reads as not found rather than leaking.
@@ -660,8 +657,7 @@ public Response getDocByID(String indexName, String entityId) throws IOException
       }
     } catch (OpenSearchException e) {
       if (e.status() == 404) {
-        throw new SearchIndexNotFoundException(
-            String.format("Failed to find doc with id %s", entityId));
+        throw SearchEngineErrors.indexNotFound(index);
       } else {
         throw new SearchException(String.format("Search failed due to %s", e.getMessage()));
       }

openmetadata-service/src/main/java/org/openmetadata/service/search/opensearch/OpenSearchSearchManager.java

@@ -56,7 +56,6 @@
 import org.openmetadata.schema.type.Include;
 import org.openmetadata.schema.utils.JsonUtils;
 import org.openmetadata.sdk.exception.SearchException;
-import org.openmetadata.sdk.exception.SearchIndexNotFoundException;
 import org.openmetadata.service.Entity;
 import org.openmetadata.service.config.CacheConfiguration;
 import org.openmetadata.service.jdbi3.ListFilter;
@@ -354,7 +353,7 @@ private SearchResultListMapper doListWithOffset(
       return new SearchResultListMapper(results, totalHits);
     } catch (OpenSearchException e) {
       if (e.status() == 404) {
-        throw new SearchIndexNotFoundException(String.format("Failed to find index %s", index));
+        throw SearchEngineErrors.indexNotFound(index);
       } else {
         throw buildSearchException(e);
       }
@@ -555,7 +554,7 @@ public SearchResultListMapper listWithDeepPagination(
           results, totalHits, lastHitSortValues, lastDocumentsInBatch);
     } catch (OpenSearchException e) {
       if (e.status() == 404) {
-        throw new SearchIndexNotFoundException(String.format("Failed to find index %s", index));
+        throw SearchEngineErrors.indexNotFound(index);
       } else {
         throw buildSearchException(e);
       }
@@ -1216,8 +1215,7 @@ public Response doSearch(
 
     } catch (OpenSearchException e) {
       if (e.status() == 404) {
-        throw new SearchIndexNotFoundException(
-            String.format("Failed to find index %s", request.getIndex()));
+        throw SearchEngineErrors.indexNotFound(request.getIndex());
       } else {
         throw buildSearchException(e);
       }
@@ -1404,8 +1402,7 @@ public SearchResultListMapper searchForExport(
       return new SearchResultListMapper(results, totalHits, lastHitSortValues);
     } catch (OpenSearchException e) {
       if (e.status() == 404) {
-        throw new SearchIndexNotFoundException(
-            String.format("Failed to find index %s", request.getIndex()));
+        throw SearchEngineErrors.indexNotFound(request.getIndex());
       } else {
         throw buildSearchException(e);
       }