Remove the _default_ mapping.

docs/reference/indices/put-mapping.asciidoc

@@ -61,11 +61,6 @@ PUT /twitter-1,twitter-2/_mapping/_doc <1>
 <1> Note that the indices specified (`twitter-1,twitter-2`) follows <<multi-index,multiple index names>> and wildcard format.
 
 
-NOTE: When updating the `_default_` mapping with the
-<<indices-put-mapping,PUT mapping>> API, the new mapping is not merged with
-the existing mapping.  Instead, the new `_default_` mapping replaces the
-existing one.
-
 [[updating-field-mappings]]
 [float]
 === Updating field mappings

docs/reference/mapping/dynamic-mapping.asciidoc

@@ -35,6 +35,3 @@ automatically or explicitly.
 include::dynamic/field-mapping.asciidoc[]
 
 include::dynamic/templates.asciidoc[]
-
-include::dynamic/default-mapping.asciidoc[]
-

docs/reference/migration/migrate_7_0/mappings.asciidoc

@@ -5,6 +5,18 @@
 
 The `_all` field deprecated in 6 have now been removed.
 
+==== The `_default_` mapping is removed
+
+The `_default_` mapping has been deprecated in 6.0 and is now removed in 7.0.
+Trying to configure a `_default_` mapping will result in an error.
+
+If an index is created in 6.x with a `_default_` mapping in addition to a
+concrete mappings, the `_default_` mapping will be removed on upgrade.
+
+If an index is created in 6.x and only has a `_default_` mapping, which implies
+this index is empty as otherwise indexed documents would have implicitly added
+a type, then the `_default_` mapping will be renamed to `_doc` on upgrade.
+
 ==== `index_options` for numeric fields has been removed
 
 The `index_options` field for numeric  fields has been deprecated in 6 and has now been removed.

modules/parent-join/src/main/java/org/elasticsearch/join/query/HasParentQueryBuilder.java

@@ -227,7 +227,7 @@ private Query parentFieldDoToQuery(QueryShardContext context) throws IOException
         }
 
         Set<String> childTypes = new HashSet<>();
-        for (DocumentMapper documentMapper : context.getMapperService().docMappers(false)) {
+        for (DocumentMapper documentMapper : context.getMapperService().docMappers()) {
             ParentFieldMapper parentFieldMapper = documentMapper.parentFieldMapper();
             if (parentFieldMapper.active() && type.equals(parentFieldMapper.type())) {
                 childTypes.add(documentMapper.type());

qa/rolling-upgrade/src/test/resources/rest-api-spec/test/old_cluster/10_basic.yml

@@ -253,3 +253,43 @@
       tasks.get:
         wait_for_completion: true
         task_id: $task
+
+---
+"Create indices that have a default mapping":
+
+  - skip:
+      features: warnings
+
+  - do:
+      warnings:
+        - "[_default_] mapping is deprecated since it is not useful anymore now that indexes cannot have more than one type"
+      indices.create:
+        index: index_with_default_mapping
+        body:
+          settings:
+            index:
+              number_of_replicas: 0
+          mappings:
+            _default_:
+              properties:
+                foo:
+                  type: long
+            my_type:
+              properties:
+                bar:
+                  type: keyword
+
+  - do:
+      warnings:
+        - "[_default_] mapping is deprecated since it is not useful anymore now that indexes cannot have more than one type"
+      indices.create:
+        index: index_with_default_mapping2
+        body:
+          settings:
+            index:
+              number_of_replicas: 0
+          mappings:
+            _default_:
+              properties:
+                foo:
+                  type: long

qa/rolling-upgrade/src/test/resources/rest-api-spec/test/upgraded_cluster/10_basic.yml

@@ -165,3 +165,41 @@
         wait_for_completion: true
         task_id: $task_id
   - match: { task.headers.X-Opaque-Id: "Reindexing Again" }
+
+---
+"Verify the indices with a default mapping were upgraded":
+
+  - skip:
+      features: warnings
+
+  - do:
+     indices.get_mapping:
+       index: index_with_default_mapping
+
+  - is_true: index_with_default_mapping.mappings.my_type
+  - is_false: index_with_default_mapping.mappings._default_
+
+  - do:
+     indices.get_mapping:
+       index: index_with_default_mapping2
+
+  - is_true: index_with_default_mapping2.mappings._doc
+  - is_false: index_with_default_mapping2.mappings._default_
+
+
+---
+"Verify that we still reject default mappings":
+
+  - skip:
+      features: warnings
+
+  - do:
+      catch: /invalid_type_name_exception/
+      indices.put_mapping:
+        index: index_with_default_mapping2
+        type: _default_
+        body:
+          _default_:
+            properties:
+              foo:
+                type:     keyword

rest-api-spec/src/main/resources/rest-api-spec/test/indices.put_mapping/10_basic.yml

@@ -67,3 +67,43 @@
             properties:
               "":
                type:     keyword
+
+---
+"Create index with _default_ mappings":
+
+  - skip:
+      version: " - 6.99.99"
+      reason:  _default_ mapping was removed in 7.0
+
+  - do:
+      catch: /invalid_type_name_exception/
+      indices.create:
+        index: test_index
+        body:
+          mappings:
+            _default_:
+              properties:
+                foo:
+                  type:     keyword
+
+---
+"POST _default_ mappings":
+
+  - skip:
+      version: " - 6.99.99"
+      reason:  _default_ mapping was removed in 7.0
+
+  - do:
+      indices.create:
+        index: test_index
+
+  - do:
+      catch: /invalid_type_name_exception/
+      indices.put_mapping:
+        index: test_index
+        type: _default_
+        body:
+          _default_:
+            properties:
+              foo:
+                type:     keyword

server/src/main/java/org/elasticsearch/action/bulk/TransportBulkAction.java

@@ -291,7 +291,7 @@ protected void doRun() throws Exception {
                         case INDEX:
                             IndexRequest indexRequest = (IndexRequest) docWriteRequest;
                             final IndexMetaData indexMetaData = metaData.index(concreteIndex);
-                            MappingMetaData mappingMd = indexMetaData.mappingOrDefault(indexRequest.type());
+                            MappingMetaData mappingMd = indexMetaData.mapping(indexRequest.type());
                             Version indexCreated = indexMetaData.getCreationVersion();
                             indexRequest.resolveRouting(metaData);
                             indexRequest.process(indexCreated, mappingMd, concreteIndex.getName());

server/src/main/java/org/elasticsearch/action/bulk/TransportShardBulkAction.java

@@ -354,7 +354,7 @@ static BulkItemResultHolder executeUpdateRequestOnce(UpdateRequest updateRequest
             case CREATED:
             case UPDATED:
                 IndexRequest indexRequest = translate.action();
-                MappingMetaData mappingMd = metaData.mappingOrDefault(indexRequest.type());
+                MappingMetaData mappingMd = metaData.mapping(indexRequest.type());
                 indexRequest.process(metaData.getCreationVersion(), mappingMd, concreteIndex);
                 result = executeIndexRequestOnPrimary(indexRequest, primary, mappingUpdater);
                 break;

server/src/main/java/org/elasticsearch/cluster/action/index/MappingUpdatedAction.java

@@ -65,9 +65,6 @@ public void setClient(Client client) {
     }
 
     private PutMappingRequestBuilder updateMappingRequest(Index index, String type, Mapping mappingUpdate, final TimeValue timeout) {
-        if (type.equals(MapperService.DEFAULT_MAPPING)) {
-            throw new IllegalArgumentException("_default_ mapping should not be updated");
-        }
         return client.preparePutMapping().setConcreteIndex(index).setType(type).setSource(mappingUpdate.toString(), XContentType.JSON)
                 .setMasterNodeTimeout(timeout).setTimeout(timeout);
     }

server/src/main/java/org/elasticsearch/cluster/metadata/IndexMetaData.java

@@ -53,7 +53,6 @@
 import org.elasticsearch.common.xcontent.XContentType;
 import org.elasticsearch.gateway.MetaDataStateFormat;
 import org.elasticsearch.index.Index;
-import org.elasticsearch.index.mapper.MapperService;
 import org.elasticsearch.index.shard.ShardId;
 import org.elasticsearch.rest.RestStatus;
 import org.joda.time.DateTime;
@@ -490,22 +489,6 @@ public Index getResizeSourceIndex() {
             ? new Index(INDEX_RESIZE_SOURCE_NAME.get(settings), INDEX_RESIZE_SOURCE_UUID.get(settings)) : null;
     }
 
-    /**
-     * Sometimes, the default mapping exists and an actual mapping is not created yet (introduced),
-     * in this case, we want to return the default mapping in case it has some default mapping definitions.
-     * <p>
-     * Note, once the mapping type is introduced, the default mapping is applied on the actual typed MappingMetaData,
-     * setting its routing, timestamp, and so on if needed.
-     */
-    @Nullable
-    public MappingMetaData mappingOrDefault(String mappingType) {
-        MappingMetaData mapping = mappings.get(mappingType);
-        if (mapping != null) {
-            return mapping;
-        }
-        return mappings.get(MapperService.DEFAULT_MAPPING);
-    }
-
     public ImmutableOpenMap<String, Custom> getCustoms() {
         return this.customs;
     }
@@ -914,6 +897,11 @@ public Builder putMapping(MappingMetaData mappingMd) {
             return this;
         }
 
+        public Builder removeMapping(String type) {
+            mappings.remove(type);
+            return this;
+        }
+
         public Builder state(State state) {
             this.state = state;
             return this;
@@ -1002,14 +990,6 @@ public IndexMetaData build() {
             ImmutableOpenMap.Builder<String, AliasMetaData> tmpAliases = aliases;
             Settings tmpSettings = settings;
 
-            // update default mapping on the MappingMetaData
-            if (mappings.containsKey(MapperService.DEFAULT_MAPPING)) {
-                MappingMetaData defaultMapping = mappings.get(MapperService.DEFAULT_MAPPING);
-                for (ObjectCursor<MappingMetaData> cursor : mappings.values()) {
-                    cursor.value.updateDefaultMapping(defaultMapping);
-                }
-            }
-
             Integer maybeNumberOfShards = settings.getAsInt(SETTING_NUMBER_OF_SHARDS, null);
             if (maybeNumberOfShards == null) {
                 throw new IllegalArgumentException("must specify numberOfShards for index [" + index + "]");

server/src/main/java/org/elasticsearch/cluster/metadata/MappingMetaData.java

@@ -134,12 +134,6 @@ private void initMappers(Map<String, Object> withoutType) {
         }
     }
 
-    void updateDefaultMapping(MappingMetaData defaultMapping) {
-        if (routing == Routing.EMPTY) {
-            routing = defaultMapping.routing();
-        }
-    }
-
     public String type() {
         return this.type;
     }

server/src/main/java/org/elasticsearch/cluster/metadata/MetaDataCreateIndexService.java

@@ -476,7 +476,7 @@ public ClusterState execute(ClusterState currentState) throws Exception {
 
                 // now, update the mappings with the actual source
                 Map<String, MappingMetaData> mappingsMetaData = new HashMap<>();
-                for (DocumentMapper mapper : mapperService.docMappers(true)) {
+                for (DocumentMapper mapper : mapperService.docMappers()) {
                     MappingMetaData mappingMd = new MappingMetaData(mapper);
                     mappingsMetaData.put(mapper.type(), mappingMd);
                 }
@@ -660,8 +660,7 @@ static IndexMetaData validateResize(ClusterState state, String sourceIndex,
             throw new IllegalStateException("index " + sourceIndex + " must be read-only to resize index. use \"index.blocks.write=true\"");
         }
 
-        if ((targetIndexMappingsTypes.size() > 1 ||
-            (targetIndexMappingsTypes.isEmpty() || targetIndexMappingsTypes.contains(MapperService.DEFAULT_MAPPING)) == false)) {
+        if (targetIndexMappingsTypes.isEmpty() == false) {
             throw new IllegalArgumentException("mappings are not allowed when resizing indices" +
                 ", all mappings are copied from the source index");
         }

server/src/main/java/org/elasticsearch/cluster/metadata/MetaDataIndexUpgradeService.java

@@ -90,6 +90,8 @@ public IndexMetaData upgradeIndexMetaData(IndexMetaData indexMetaData, Version m
         // we have to run this first otherwise in we try to create IndexSettings
         // with broken settings and fail in checkMappingsCompatibility
         newMetaData = archiveBrokenIndexSettings(newMetaData);
+        // remove the _default_ mapping if applicable
+        newMetaData = MapperService.MAPPINGS_METADATA_6x_UPGRADER.apply(newMetaData);
         // only run the check with the upgraded settings!!
         checkMappingsCompatibility(newMetaData);
         // apply plugin checks