diff --git a/dev-tools/create_bwc_index.py b/dev-tools/create_bwc_index.py
index 5d663ca69f3..83a35941577 100644
--- a/dev-tools/create_bwc_index.py
+++ b/dev-tools/create_bwc_index.py
@@ -149,6 +149,16 @@ def start_node(version, release_dir, data_dir, repo_dir, tcp_port=DEFAULT_TRANSP
     cmd.append('-f') # version before 1.0 start in background automatically
   return subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
 
+def install_plugin(version, release_dir, plugin_name):
+  run_plugin(version, release_dir, 'install', [plugin_name])
+
+def remove_plugin(version, release_dir, plugin_name):
+  run_plugin(version, release_dir, 'remove', [plugin_name])
+
+def run_plugin(version, release_dir, plugin_cmd, args):
+  cmd = [os.path.join(release_dir, 'bin/plugin'), plugin_cmd] + args
+  subprocess.check_call(cmd)
+
 def create_client(http_port=DEFAULT_HTTP_TCP_PORT, timeout=30):
   logging.info('Waiting for node to startup')
   for _ in range(0, timeout):
diff --git a/dev-tools/create_bwc_index_with_plugin_mappings.py b/dev-tools/create_bwc_index_with_plugin_mappings.py
new file mode 100644
index 00000000000..c30de412d1d
--- /dev/null
+++ b/dev-tools/create_bwc_index_with_plugin_mappings.py
@@ -0,0 +1,124 @@
+import create_bwc_index
+import logging
+import os
+import random
+import shutil
+import subprocess
+import sys
+import tempfile
+
+def fetch_version(version):
+  logging.info('fetching ES version %s' % version)
+  if subprocess.call([sys.executable, os.path.join(os.path.split(sys.argv[0])[0], 'get-bwc-version.py'), version]) != 0:
+    raise RuntimeError('failed to download ES version %s' % version)
+
+def create_index(plugin, mapping, docs):
+  '''
+  Creates a static back compat index (.zip) with mappings using fields defined in plugins.
+  '''
+  
+  logging.basicConfig(format='[%(levelname)s] [%(asctime)s] %(message)s', level=logging.INFO,
+                      datefmt='%Y-%m-%d %I:%M:%S %p')
+  logging.getLogger('elasticsearch').setLevel(logging.ERROR)
+  logging.getLogger('urllib3').setLevel(logging.WARN)
+
+  tmp_dir = tempfile.mkdtemp()
+  plugin_installed = False
+  node = None
+  try:
+    data_dir = os.path.join(tmp_dir, 'data')
+    repo_dir = os.path.join(tmp_dir, 'repo')
+    logging.info('Temp data dir: %s' % data_dir)
+    logging.info('Temp repo dir: %s' % repo_dir)
+
+    version = '2.0.0'
+    classifier = '%s-%s' %(plugin, version)
+    index_name = 'index-%s' % classifier
+
+    # Download old ES releases if necessary:
+    release_dir = os.path.join('backwards', 'elasticsearch-%s' % version)
+    if not os.path.exists(release_dir):
+      fetch_version(version)
+
+    create_bwc_index.install_plugin(version, release_dir, plugin)
+    plugin_installed = True
+    node = create_bwc_index.start_node(version, release_dir, data_dir, repo_dir, cluster_name=index_name)
+    client = create_bwc_index.create_client()
+    put_plugin_mappings(client, index_name, mapping, docs)
+    create_bwc_index.shutdown_node(node)
+
+    print('%s server output:\n%s' % (version, node.stdout.read().decode('utf-8')))
+    node = None
+    create_bwc_index.compress_index(classifier, tmp_dir, 'plugins/%s/src/test/resources/indices/bwc' %plugin)
+  finally:
+    if node is not None:
+      create_bwc_index.shutdown_node(node)
+    if plugin_installed:
+      create_bwc_index.remove_plugin(version, release_dir, plugin)
+    shutil.rmtree(tmp_dir)
+
+def put_plugin_mappings(client, index_name, mapping, docs):
+  client.indices.delete(index=index_name, ignore=404)
+  logging.info('Create single shard test index')
+
+  client.indices.create(index=index_name, body={
+    'settings': {
+      'number_of_shards': 1,
+      'number_of_replicas': 0
+    },
+    'mappings': {
+      'type': mapping
+    }
+  })
+  health = client.cluster.health(wait_for_status='green', wait_for_relocating_shards=0)
+  assert health['timed_out'] == False, 'cluster health timed out %s' % health
+
+  logging.info('Indexing documents')
+  for i in range(len(docs)):
+    client.index(index=index_name, doc_type="type", id=str(i), body=docs[i])
+  logging.info('Flushing index')
+  client.indices.flush(index=index_name)
+
+  logging.info('Running basic checks')
+  count = client.count(index=index_name)['count']
+  assert count == len(docs), "expected %d docs, got %d" %(len(docs), count)
+
+def main():
+  docs = [
+    {
+      "foo": "abc"
+    },
+    {
+      "foo": "abcdef"
+    },
+    {
+      "foo": "a"
+    }
+  ]
+
+  murmur3_mapping = {
+    'properties': {
+      'foo': {
+        'type': 'string',
+        'fields': {
+          'hash': {
+            'type': 'murmur3'
+          }
+        }
+      }
+    }
+  }
+
+  create_index("mapper-murmur3", murmur3_mapping, docs)
+
+  size_mapping = {
+    '_size': {
+      'enabled': True
+    }
+  }
+
+  create_index("mapper-size", size_mapping, docs)
+
+if __name__ == '__main__':
+  main()
+
diff --git a/plugins/mapper-murmur3/src/test/java/org/elasticsearch/index/mapper/murmur3/Murmur3FieldMapperUpgradeTests.java b/plugins/mapper-murmur3/src/test/java/org/elasticsearch/index/mapper/murmur3/Murmur3FieldMapperUpgradeTests.java
new file mode 100644
index 00000000000..8ede994e2f4
--- /dev/null
+++ b/plugins/mapper-murmur3/src/test/java/org/elasticsearch/index/mapper/murmur3/Murmur3FieldMapperUpgradeTests.java
@@ -0,0 +1,77 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.index.mapper.murmur3;
+
+import org.apache.lucene.util.LuceneTestCase;
+import org.apache.lucene.util.TestUtil;
+import org.elasticsearch.action.search.SearchResponse;
+import org.elasticsearch.env.NodeEnvironment;
+import org.elasticsearch.plugin.mapper.MapperMurmur3Plugin;
+import org.elasticsearch.plugins.Plugin;
+import org.elasticsearch.search.aggregations.AggregationBuilders;
+import org.elasticsearch.search.aggregations.metrics.cardinality.Cardinality;
+import org.elasticsearch.test.ESIntegTestCase;
+import org.elasticsearch.test.hamcrest.ElasticsearchAssertions;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Collection;
+import java.util.Collections;
+
+@ESIntegTestCase.ClusterScope(scope = ESIntegTestCase.Scope.TEST, numDataNodes = 0)
+@LuceneTestCase.SuppressFileSystems("ExtrasFS")
+public class Murmur3FieldMapperUpgradeTests extends ESIntegTestCase {
+
+    @Override
+    protected Collection<Class<? extends Plugin>> nodePlugins() {
+        return Collections.singleton(MapperMurmur3Plugin.class);
+    }
+
+    public void testUpgradeOldMapping() throws IOException {
+        final String indexName = "index-mapper-murmur3-2.0.0";
+        Path unzipDir = createTempDir();
+        Path unzipDataDir = unzipDir.resolve("data");
+        Path backwardsIndex = getBwcIndicesPath().resolve(indexName + ".zip");
+        try (InputStream stream = Files.newInputStream(backwardsIndex)) {
+            TestUtil.unzip(stream, unzipDir);
+        }
+        assertTrue(Files.exists(unzipDataDir));
+
+        final String node = internalCluster().startNode();
+        Path[] nodePaths = internalCluster().getInstance(NodeEnvironment.class, node).nodeDataPaths();
+        assertEquals(1, nodePaths.length);
+        Path dataPath = nodePaths[0].resolve(NodeEnvironment.INDICES_FOLDER);
+        assertFalse(Files.exists(dataPath));
+        Path src = unzipDataDir.resolve(indexName + "/nodes/0/indices");
+        Files.move(src, dataPath);
+
+        ensureYellow();
+        final SearchResponse countResponse = client().prepareSearch(indexName).setSize(0).get();
+        ElasticsearchAssertions.assertHitCount(countResponse, 3L);
+
+        final SearchResponse cardinalityResponse = client().prepareSearch(indexName).addAggregation(
+                AggregationBuilders.cardinality("card").field("foo.hash")).get();
+        Cardinality cardinality = cardinalityResponse.getAggregations().get("card");
+        assertEquals(3L, cardinality.getValue());
+    }
+
+}
diff --git a/plugins/mapper-murmur3/src/test/resources/indices/bwc/index-mapper-murmur3-2.0.0.zip b/plugins/mapper-murmur3/src/test/resources/indices/bwc/index-mapper-murmur3-2.0.0.zip
new file mode 100644
index 00000000000..0b69aac180b
Binary files /dev/null and b/plugins/mapper-murmur3/src/test/resources/indices/bwc/index-mapper-murmur3-2.0.0.zip differ
diff --git a/plugins/mapper-size/src/test/java/org/elasticsearch/index/mapper/size/SizeFieldMapperUpgradeTests.java b/plugins/mapper-size/src/test/java/org/elasticsearch/index/mapper/size/SizeFieldMapperUpgradeTests.java
new file mode 100644
index 00000000000..4a5257784f8
--- /dev/null
+++ b/plugins/mapper-size/src/test/java/org/elasticsearch/index/mapper/size/SizeFieldMapperUpgradeTests.java
@@ -0,0 +1,88 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.index.mapper.size;
+
+import org.apache.lucene.util.LuceneTestCase;
+import org.apache.lucene.util.TestUtil;
+import org.elasticsearch.action.search.SearchResponse;
+import org.elasticsearch.env.NodeEnvironment;
+import org.elasticsearch.plugin.mapper.MapperSizePlugin;
+import org.elasticsearch.plugins.Plugin;
+import org.elasticsearch.search.SearchHit;
+import org.elasticsearch.search.SearchHitField;
+import org.elasticsearch.test.ESIntegTestCase;
+import org.elasticsearch.test.hamcrest.ElasticsearchAssertions;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Map;
+
+@ESIntegTestCase.ClusterScope(scope = ESIntegTestCase.Scope.TEST, numDataNodes = 0)
+@LuceneTestCase.SuppressFileSystems("ExtrasFS")
+public class SizeFieldMapperUpgradeTests extends ESIntegTestCase {
+
+    @Override
+    protected Collection<Class<? extends Plugin>> nodePlugins() {
+        return Collections.singleton(MapperSizePlugin.class);
+    }
+
+    public void testUpgradeOldMapping() throws IOException {
+        final String indexName = "index-mapper-size-2.0.0";
+        Path unzipDir = createTempDir();
+        Path unzipDataDir = unzipDir.resolve("data");
+        Path backwardsIndex = getBwcIndicesPath().resolve(indexName + ".zip");
+        try (InputStream stream = Files.newInputStream(backwardsIndex)) {
+            TestUtil.unzip(stream, unzipDir);
+        }
+        assertTrue(Files.exists(unzipDataDir));
+
+        final String node = internalCluster().startNode();
+        Path[] nodePaths = internalCluster().getInstance(NodeEnvironment.class, node).nodeDataPaths();
+        assertEquals(1, nodePaths.length);
+        Path dataPath = nodePaths[0].resolve(NodeEnvironment.INDICES_FOLDER);
+        assertFalse(Files.exists(dataPath));
+        Path src = unzipDataDir.resolve(indexName + "/nodes/0/indices");
+        Files.move(src, dataPath);
+
+        ensureYellow();
+        final SearchResponse countResponse = client().prepareSearch(indexName).setSize(0).get();
+        ElasticsearchAssertions.assertHitCount(countResponse, 3L);
+
+        final SearchResponse sizeResponse = client().prepareSearch(indexName)
+                .addField("_source")
+                .addField("_size")
+                .get();
+        ElasticsearchAssertions.assertHitCount(sizeResponse, 3L);
+        for (SearchHit hit : sizeResponse.getHits().getHits()) {
+            String source = hit.getSourceAsString();
+            assertNotNull(source);
+            Map<String, SearchHitField> fields = hit.getFields();
+            assertTrue(fields.containsKey("_size"));
+            Number size = fields.get("_size").getValue();
+            assertNotNull(size);
+            assertEquals(source.length(), size.longValue());
+        }
+    }
+
+}
diff --git a/plugins/mapper-size/src/test/resources/indices/bwc/index-mapper-size-2.0.0.zip b/plugins/mapper-size/src/test/resources/indices/bwc/index-mapper-size-2.0.0.zip
new file mode 100644
index 00000000000..0a74f835c3e
Binary files /dev/null and b/plugins/mapper-size/src/test/resources/indices/bwc/index-mapper-size-2.0.0.zip differ