Revert "Deprecate _source.mode in mappings (#117106)" (#117151)

This reverts #117106. Bwc tests fail, because older nodes are killed with the following error:

```
[2024-11-20T10:54:58,600][ERROR][o.e.b.ElasticsearchUncaughtExceptionHandler] [v8.17.0-0] fatal error in thread [elasticsearch[v8.17.0-0
][clusterApplierService#updateTask][T#1]], exiting java.lang.AssertionError: provided source [{"_doc":{"_data_stream_timestamp":{"enabled":true},"_source":{},"properties":{"@timestamp":{"type":"date"},"k8s":{"properties":{"pod":{"properties":{"ip":{"type":"ip"},"name":{"type":"keyword"},"network":{"properties":{"rx":{"type":"long"},"tx":{"type":"long"}}},"uid":{"type":"keyword","time_series_dimension":true}}}}},"metricset":{"type":"keyword","time_series_dimension":true}}}}] differs from mapping [{"_doc":{"_data_stream_timestamp":{"enabled":true},"_source":{"mode":"synthetic"},"properties":{"@timestamp":{"type":"date"},"k8s":{"properties":{"pod":{"properties":{"ip":{"type":"ip"},"name":{"type":"keyword"},"network":{"properties":{"rx":{"type":"long"},"tx":{"type":"long"}}},"uid":{"type":"keyword","time_series_dimension":true}}}}},"metricset":{"type":"keyword","time_series_dimension":true}}}}]
        at [email protected]/org.elasticsearch.index.mapper.DocumentMapper.<init>(DocumentMapper.java:66)
        at [email protected]/org.elasticsearch.index.mapper.MapperService.newDocumentMapper(MapperService.java:588)
        at [email protected]/org.elasticsearch.index.mapper.MapperService.updateMapping(MapperService.java:346)
        at [email protected]/org.elasticsearch.index.IndexService.updateMapping(IndexService.java:840)
        at [email protected]/org.elasticsearch.indices.cluster.IndicesClusterStateService.createIndicesAndUpdateShards(IndicesClusterStateService.java:583)
        at [email protected]/org.elasticsearch.indices.cluster.IndicesClusterStateService.doApplyClusterState(IndicesClusterStateService.java:306)
        at [email protected]/org.elasticsearch.indices.cluster.IndicesClusterStateService.applyClusterState(IndicesClusterStateService.java:260)
        at [email protected]/org.elasticsearch.cluster.service.ClusterApplierService.callClusterStateAppliers(ClusterApplierService.java:544)
        at [email protected]/org.elasticsearch.cluster.service.ClusterApplierService.callClusterStateAppliers(ClusterApplierService.java:530)
        at [email protected]/org.elasticsearch.cluster.service.ClusterApplierService.applyChanges(ClusterApplierService.java:503)
        at [email protected]/org.elasticsearch.cluster.service.ClusterApplierService.runTask(ClusterApplierService.java:432)
        at [email protected]/org.elasticsearch.cluster.service.ClusterApplierService$UpdateTask.run(ClusterApplierService.java:157)
        at [email protected]/org.elasticsearch.common.util.concurrent.ThreadContext$ContextPreservingRunnable.run(ThreadContext.java:956)
        at [email protected]/org.elasticsearch.common.util.concurrent.PrioritizedEsThreadPoolExecutor$TieBreakingPrioritizedRunnable.runAndClean(PrioritizedEsThreadPoolExecutor.java:218)
        at [email protected]/org.elasticsearch.common.util.concurrent.PrioritizedEsThreadPoolExecutor$TieBreakingPrioritizedRunnable.run(PrioritizedEsThreadPoolExecutor.java:184)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642)
        at java.base/java.lang.Thread.run(Thread.java:1575)
```

The `mode` parameter no longer gets serialized for new indices. However on the older nodes still serialize the `mode` parameter, which caused the menioned assertion to fail. Reverting for now and see how best to address this bwc serialization issue.

We can only stop serializing mode, when all nodes are on the same version.  Unfortunately we can't invoke `c.clusterTransportVersion().get()` from parser or builder, because that calling thread isn't allowed to call `clusterService.state()`.

Author: martijnvg

build-tools-internal/src/main/java/org/elasticsearch/gradle/internal/test/rest/compat/compat/RestCompatTestTransformTask.java

@@ -135,8 +135,8 @@ public void skipTest(String fullTestName, String reason) {
         // For example: indices.get_mapping/20_missing_type/Non-existent type returns 404
         // However, the folder can be arbitrarily nest so, a == a1/a2/a3, and the test name can include forward slashes, so c == c1/c2/c3
         // So we also need to support a1/a2/a3/b/c1/c2/c3
-        boolean limitTo3Separators = fullTestName.equals("logsdb/20_source_mapping/include/exclude is supported with stored _source");
-        String[] testParts = limitTo3Separators ? fullTestName.split("/", 3) : fullTestName.split("/");
+
+        String[] testParts = fullTestName.split("/");
         if (testParts.length < 3) {
             throw new IllegalArgumentException(
                 "To skip tests, all 3 parts [folder/file/test name] must be defined. found [" + fullTestName + "]"

docs/changelog/116689.yaml

@@ -17,6 +17,7 @@
 import org.elasticsearch.common.network.InetAddresses;
 import org.elasticsearch.common.time.DateFormatter;
 import org.elasticsearch.common.time.FormatNames;
+import org.elasticsearch.test.MapMatcher;
 import org.elasticsearch.test.cluster.ElasticsearchCluster;
 import org.elasticsearch.test.cluster.local.distribution.DistributionType;
 import org.elasticsearch.test.rest.RestTestLegacyFeatures;
@@ -30,6 +31,9 @@
 import java.util.Map;
 import java.util.function.Supplier;
 
+import static org.elasticsearch.test.MapMatcher.assertMap;
+import static org.elasticsearch.test.MapMatcher.matchesMap;
+
 public class LogsIndexModeFullClusterRestartIT extends ParameterizedFullClusterRestartTestCase {
 
     @ClassRule
@@ -168,16 +172,22 @@ public void testLogsIndexing() throws IOException {
             assertOK(bulkIndexResponse);
             assertThat(entityAsMap(bulkIndexResponse).get("errors"), Matchers.is(false));
 
-            assertIndexSettings(0, Matchers.nullValue());
-            assertIndexSettings(1, Matchers.equalTo("logsdb"));
+            assertIndexMappingsAndSettings(0, Matchers.nullValue(), matchesMap().extraOk());
+            assertIndexMappingsAndSettings(
+                1,
+                Matchers.equalTo("logsdb"),
+                matchesMap().extraOk().entry("_source", Map.of("mode", "synthetic"))
+            );
         }
     }
 
-    private void assertIndexSettings(int backingIndex, final Matcher<Object> indexModeMatcher) throws IOException {
+    private void assertIndexMappingsAndSettings(int backingIndex, final Matcher<Object> indexModeMatcher, final MapMatcher mappingsMatcher)
+        throws IOException {
         assertThat(
             getSettings(client(), getWriteBackingIndex(client(), "logs-apache-production", backingIndex)).get("index.mode"),
             indexModeMatcher
         );
+        assertMap(getIndexMappingAsMap(getWriteBackingIndex(client(), "logs-apache-production", backingIndex)), mappingsMatcher);
     }
 
     private static Request createDataStream(final String dataStreamName) {

qa/full-cluster-restart/src/javaRestTest/java/org/elasticsearch/upgrades/LogsIndexModeFullClusterRestartIT.java

@@ -17,6 +17,7 @@
 import org.elasticsearch.common.network.InetAddresses;
 import org.elasticsearch.common.time.DateFormatter;
 import org.elasticsearch.common.time.FormatNames;
+import org.elasticsearch.test.MapMatcher;
 import org.elasticsearch.test.cluster.ElasticsearchCluster;
 import org.elasticsearch.test.cluster.local.distribution.DistributionType;
 import org.hamcrest.Matcher;
@@ -29,6 +30,9 @@
 import java.util.Map;
 import java.util.function.Supplier;
 
+import static org.elasticsearch.test.MapMatcher.assertMap;
+import static org.elasticsearch.test.MapMatcher.matchesMap;
+
 public class LogsIndexModeRollingUpgradeIT extends AbstractRollingUpgradeTestCase {
 
     @ClassRule()
@@ -156,10 +160,14 @@ public void testLogsIndexing() throws IOException {
             assertOK(bulkIndexResponse);
             assertThat(entityAsMap(bulkIndexResponse).get("errors"), Matchers.is(false));
 
-            assertIndexSettings(0, Matchers.nullValue());
-            assertIndexSettings(1, Matchers.nullValue());
-            assertIndexSettings(2, Matchers.nullValue());
-            assertIndexSettings(3, Matchers.equalTo("logsdb"));
+            assertIndexMappingsAndSettings(0, Matchers.nullValue(), matchesMap().extraOk());
+            assertIndexMappingsAndSettings(1, Matchers.nullValue(), matchesMap().extraOk());
+            assertIndexMappingsAndSettings(2, Matchers.nullValue(), matchesMap().extraOk());
+            assertIndexMappingsAndSettings(
+                3,
+                Matchers.equalTo("logsdb"),
+                matchesMap().extraOk().entry("_source", Map.of("mode", "synthetic"))
+            );
         }
     }
 
@@ -175,11 +183,13 @@ static void enableLogsdbByDefault() throws IOException {
         assertOK(client().performRequest(request));
     }
 
-    private void assertIndexSettings(int backingIndex, final Matcher<Object> indexModeMatcher) throws IOException {
+    private void assertIndexMappingsAndSettings(int backingIndex, final Matcher<Object> indexModeMatcher, final MapMatcher mappingsMatcher)
+        throws IOException {
         assertThat(
             getSettings(client(), getWriteBackingIndex(client(), "logs-apache-production", backingIndex)).get("index.mode"),
             indexModeMatcher
         );
+        assertMap(getIndexMappingAsMap(getWriteBackingIndex(client(), "logs-apache-production", backingIndex)), mappingsMatcher);
     }
 
     private static Request createDataStream(final String dataStreamName) {

qa/rolling-upgrade/src/javaRestTest/java/org/elasticsearch/upgrades/LogsIndexModeRollingUpgradeIT.java

@@ -247,10 +247,4 @@ tasks.named("precommit").configure {
 tasks.named("yamlRestTestV7CompatTransform").configure({ task ->
   task.skipTest("indices.sort/10_basic/Index Sort", "warning does not exist for compatibility")
   task.skipTest("search/330_fetch_fields/Test search rewrite", "warning does not exist for compatibility")
-  task.skipTest("tsdb/20_mapping/stored source is supported", "no longer serialize source_mode")
-  task.skipTest("tsdb/20_mapping/Synthetic source", "no longer serialize source_mode")
-  task.skipTest("logsdb/10_settings/create logs index", "no longer serialize source_mode")
-  task.skipTest("logsdb/20_source_mapping/stored _source mode is supported", "no longer serialize source_mode")
-  task.skipTest("logsdb/20_source_mapping/include/exclude is supported with stored _source", "no longer serialize source_mode")
-  task.skipTest("logsdb/20_source_mapping/synthetic _source is default", "no longer serialize source_mode")
 })

rest-api-spec/build.gradle

@@ -77,6 +77,11 @@ create logs index:
   - is_true: test
   - match: { test.settings.index.mode: "logsdb" }
 
+  - do:
+      indices.get_mapping:
+        index: test
+  - match: { test.mappings._source.mode: synthetic }
+
 ---
 using default timestamp field mapping:
   - requires:

rest-api-spec/src/yamlRestTest/resources/rest-api-spec/test/logsdb/10_settings.yml

@@ -13,10 +13,10 @@ synthetic _source is default:
             index:
               mode: logsdb
   - do:
-      indices.get_settings:
+      indices.get:
         index: test-default-source
-  - match: { test-default-source.settings.index.mode: logsdb }
-  - match: { test-default-source.settings.index.mapping.source.mode: null }
+
+  - match: { test-default-source.mappings._source.mode: "synthetic" }
 
 ---
 stored _source mode is supported:
@@ -28,12 +28,11 @@ stored _source mode is supported:
             index:
               mode: logsdb
               mapping.source.mode: stored
-
   - do:
-      indices.get_settings:
+      indices.get:
         index: test-stored-source
-  - match: { test-stored-source.settings.index.mode: logsdb }
-  - match: { test-stored-source.settings.index.mapping.source.mode: stored }
+
+  - match: { test-stored-source.mappings._source.mode: "stored" }
 
 ---
 disabled _source is not supported:
@@ -111,6 +110,7 @@ include/exclude is supported with stored _source:
       indices.get:
         index: test-includes
 
+  - match: { test-includes.mappings._source.mode: "stored" }
   - match: { test-includes.mappings._source.includes: ["a"] }
 
   - do:
@@ -129,4 +129,5 @@ include/exclude is supported with stored _source:
       indices.get:
         index: test-excludes
 
+  - match: { test-excludes.mappings._source.mode: "stored" }
   - match: { test-excludes.mappings._source.excludes: ["b"] }

rest-api-spec/src/yamlRestTest/resources/rest-api-spec/test/logsdb/20_source_mapping.yml

@@ -450,6 +450,11 @@ nested fields:
                 type: long
                 time_series_metric: gauge
 
+  - do:
+      indices.get_mapping: {}
+
+  - match: {tsdb-synthetic.mappings._source.mode: synthetic}
+
 ---
 stored source is supported:
   - requires:
@@ -481,6 +486,12 @@ stored source is supported:
                         type: keyword
                         time_series_dimension: true
 
+  - do:
+      indices.get:
+        index: tsdb_index
+
+  - match: { tsdb_index.mappings._source.mode: "stored" }
+
 ---
 disabled source is not supported:
   - requires:

rest-api-spec/src/yamlRestTest/resources/rest-api-spec/test/tsdb/20_mapping.yml

@@ -11,7 +11,6 @@
 
 import org.elasticsearch.cluster.metadata.IndexMetadata;
 import org.elasticsearch.cluster.metadata.Metadata;
-import org.elasticsearch.cluster.service.ClusterService;
 import org.elasticsearch.common.compress.CompressedXContent;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.core.CheckedFunction;
@@ -55,7 +54,7 @@ Settings getAdditionalIndexSettings(
     /**
      * Infrastructure class that holds services that can be used by {@link IndexSettingProvider} instances.
      */
-    record Parameters(ClusterService clusterService, CheckedFunction<IndexMetadata, MapperService, IOException> mapperServiceFactory) {
+    record Parameters(CheckedFunction<IndexMetadata, MapperService, IOException> mapperServiceFactory) {
 
     }
 

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

@@ -121,7 +121,6 @@ private static IndexVersion def(int id, Version luceneVersion) {
     public static final IndexVersion ADD_ROLE_MAPPING_CLEANUP_MIGRATION = def(8_518_00_0, Version.LUCENE_9_12_0);
     public static final IndexVersion LOGSDB_DEFAULT_IGNORE_DYNAMIC_BEYOND_LIMIT_BACKPORT = def(8_519_00_0, Version.LUCENE_9_12_0);
     public static final IndexVersion TIME_BASED_K_ORDERED_DOC_ID_BACKPORT = def(8_520_00_0, Version.LUCENE_9_12_0);
-    public static final IndexVersion DEPRECATE_SOURCE_MODE_MAPPER = def(8_521_00_0, Version.LUCENE_9_12_0);
     /*
      * STOP! READ THIS FIRST! No, really,
      *        ____ _____ ___  ____  _        ____  _____    _    ____    _____ _   _ ___ ____    _____ ___ ____  ____ _____ _