Removing index alias creation for deprecated transforms notification index (#117583)

* Removing index alias creation for deprecated transforms notification index

* Update docs/changelog/117583.yaml

* Updating changelog

* Updating deprecation area to Transform

---------

Co-authored-by: Elastic Machine <[email protected]>

Author: dan-rubinstein

docs/changelog/117583.yaml

@@ -0,0 +1,17 @@
+pr: 117583
+summary: Removing index alias creation for deprecated transforms notification index
+area: Machine Learning
+type: deprecation
+issues: []
+deprecation:
+  title: Removing index alias creation for deprecated transforms notification index
+  area: Transform
+  details: >-
+    As part of the migration from 7.x to 8.x, the `.data-frame-notifications-1` index
+    was deprecated and replaced with the `.transform-notifications-000002` index.
+    The index is no longer created by default, all writes are directed to the new index,
+    and any clusters with the deprecated index will have an alias created to ensure that
+    reads are still retrieving data that was written to the index before the migration to 8.x.
+    This change removes the alias from the deprecated index in 9.x. Any clusters with the alias present
+    will retain it, but it will not be created on new clusters.
+  impact: No known end user impact.

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/transform/transforms/persistence/TransformInternalIndexConstants.java

@@ -45,7 +45,6 @@ public final class TransformInternalIndexConstants {
     public static final String AUDIT_TEMPLATE_VERSION = "000002";
     public static final String AUDIT_INDEX_PREFIX = TRANSFORM_PREFIX + "notifications-";
     public static final String AUDIT_INDEX_PATTERN = AUDIT_INDEX_PREFIX + "*";
-    public static final String AUDIT_INDEX_DEPRECATED = TRANSFORM_PREFIX_DEPRECATED + "notifications-1";
     public static final String AUDIT_INDEX_PATTERN_DEPRECATED = TRANSFORM_PREFIX_DEPRECATED + "notifications-*";
 
     public static final String AUDIT_INDEX_READ_ALIAS = TRANSFORM_PREFIX + "notifications-read";

x-pack/plugin/transform/qa/single-node-tests/src/javaRestTest/java/org/elasticsearch/xpack/transform/integration/TransformAuditorIT.java

@@ -8,9 +8,6 @@
 package org.elasticsearch.xpack.transform.integration;
 
 import org.elasticsearch.client.Request;
-import org.elasticsearch.client.RequestOptions;
-import org.elasticsearch.common.Strings;
-import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.xpack.core.transform.transforms.persistence.TransformInternalIndexConstants;
 import org.junit.Before;
 
@@ -92,28 +89,4 @@ public void testAuditorWritesAudits() throws Exception {
         });
 
     }
-
-    public void testAliasCreatedforBWCIndexes() throws Exception {
-        Settings.Builder settings = indexSettings(1, 0);
-
-        // These indices should only exist if created in previous versions, ignore the deprecation warning for this test
-        RequestOptions options = expectWarnings(
-            "index name ["
-                + TransformInternalIndexConstants.AUDIT_INDEX_DEPRECATED
-                + "] starts "
-                + "with a dot '.', in the next major version, index names starting with a dot are reserved for hidden indices "
-                + "and system indices"
-        ).toBuilder().addHeader("X-elastic-product-origin", "elastic").build();
-        Request request = new Request("PUT", "/" + TransformInternalIndexConstants.AUDIT_INDEX_DEPRECATED);
-        String entity = "{\"settings\": " + Strings.toString(settings.build()) + "}";
-        request.setJsonEntity(entity);
-        request.setOptions(options);
-        client().performRequest(request);
-
-        assertBusy(
-            () -> assertTrue(
-                aliasExists(TransformInternalIndexConstants.AUDIT_INDEX_DEPRECATED, TransformInternalIndexConstants.AUDIT_INDEX_READ_ALIAS)
-            )
-        );
-    }
 }

x-pack/plugin/transform/src/main/java/org/elasticsearch/xpack/transform/TransformClusterStateListener.java

@@ -9,26 +9,18 @@
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
-import org.elasticsearch.action.ActionListener;
-import org.elasticsearch.action.admin.indices.alias.IndicesAliasesRequest;
-import org.elasticsearch.action.admin.indices.alias.IndicesAliasesResponse;
 import org.elasticsearch.client.internal.Client;
 import org.elasticsearch.cluster.ClusterChangedEvent;
 import org.elasticsearch.cluster.ClusterState;
 import org.elasticsearch.cluster.ClusterStateListener;
-import org.elasticsearch.cluster.metadata.Metadata;
 import org.elasticsearch.cluster.service.ClusterService;
 import org.elasticsearch.gateway.GatewayService;
-import org.elasticsearch.xpack.core.transform.transforms.persistence.TransformInternalIndexConstants;
 
 import java.util.Optional;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Supplier;
 
-import static org.elasticsearch.xpack.core.ClientHelper.TRANSFORM_ORIGIN;
-import static org.elasticsearch.xpack.core.ClientHelper.executeAsyncWithOrigin;
-
 class TransformClusterStateListener implements ClusterStateListener, Supplier<Optional<ClusterState>> {
 
     private static final Logger logger = LogManager.getLogger(TransformClusterStateListener.class);
@@ -51,61 +43,6 @@ public void clusterChanged(ClusterChangedEvent event) {
         }
 
         clusterState.set(event.state());
-
-        // The atomic flag prevents multiple simultaneous attempts to run alias creation
-        // if there is a flurry of cluster state updates in quick succession
-        if (event.localNodeMaster() && isIndexCreationInProgress.compareAndSet(false, true)) {
-            createAuditAliasForDataFrameBWC(event.state(), client, ActionListener.wrap(r -> {
-                isIndexCreationInProgress.set(false);
-                if (r) {
-                    logger.info("Created alias for deprecated data frame notifications index");
-                } else {
-                    logger.debug("Skipped creating alias for deprecated data frame notifications index");
-                }
-            }, e -> {
-                isIndexCreationInProgress.set(false);
-                logger.error("Error creating alias for deprecated data frame notifications index", e);
-            }));
-        }
-    }
-
-    private static void createAuditAliasForDataFrameBWC(ClusterState state, Client client, final ActionListener<Boolean> finalListener) {
-
-        // check if old audit index exists, no need to create the alias if it does not
-        if (state.getMetadata().hasIndexAbstraction(TransformInternalIndexConstants.AUDIT_INDEX_DEPRECATED) == false) {
-            finalListener.onResponse(false);
-            return;
-        }
-
-        Metadata metadata = state.metadata();
-        if (state.getMetadata()
-            .getIndicesLookup()
-            .get(TransformInternalIndexConstants.AUDIT_INDEX_DEPRECATED)
-            .getIndices()
-            .stream()
-            .anyMatch(name -> metadata.index(name).getAliases().containsKey(TransformInternalIndexConstants.AUDIT_INDEX_READ_ALIAS))) {
-            finalListener.onResponse(false);
-            return;
-        }
-
-        final IndicesAliasesRequest request = client.admin()
-            .indices()
-            .prepareAliases()
-            .addAliasAction(
-                IndicesAliasesRequest.AliasActions.add()
-                    .index(TransformInternalIndexConstants.AUDIT_INDEX_DEPRECATED)
-                    .alias(TransformInternalIndexConstants.AUDIT_INDEX_READ_ALIAS)
-                    .isHidden(true)
-            )
-            .request();
-
-        executeAsyncWithOrigin(
-            client.threadPool().getThreadContext(),
-            TRANSFORM_ORIGIN,
-            request,
-            ActionListener.<IndicesAliasesResponse>wrap(r -> finalListener.onResponse(r.isAcknowledged()), finalListener::onFailure),
-            client.admin().indices()::aliases
-        );
     }
 
     /**