Update doc about reindexing from a remote cluster
@@ -548,14 +548,47 @@ Migrating from Elasticsearch to Elassandra
------------------------------------------
Because of data distribution and because Elassandra stores the _source document in Cassandra SSTables, restoring an Elasticsearch snapshot won't work. In order
-to import data from an existing Elasticsearch cluster to Elassandra, you can use the `logstash elasticsearch input plugin <https://www.elastic.co/guide/en/logstash/5.5/plugins-inputs-elasticsearch.html>`_
-and the `cassandra output plugin <https://github.com/PerimeterX/logstash-output-cassandra>`_.
+to import data from an existing Elasticsearch cluster to Elassandra, you can use these solutions:
+
+* Use `logstash elasticsearch input plugin <https://www.elastic.co/guide/en/logstash/5.5/plugins-inputs-elasticsearch.html>`_
+ and the `elasticsearch output plugin <https://www.elastic.co/guide/en/logstash/6.8/plugins-outputs-elasticsearch.html>`_ or
+ the `cassandra output plugin <https://github.com/PerimeterX/logstash-output-cassandra>`_. The cassandra output plugin
+ requires a more sophisticated configuration but distributes write load on all Elassandra nodes, while the Elasticsearch
+ output plugin require some heap memory to process bulk inserts.
+* Reindex from a remote Elasticsearch cluster as shown bellow:
+
+.. code::
+
+ curl -XPOST -H "Content-Type: application/json" "http://localhost:9200/_reindex" -d'{
+ "source": {
+ "remote": {
+ "host": "http://localhost:9201",
+ "socket_timeout": "1m",
+ "connect_timeout": "10s"
+ },
+ "index": "source_index"
+ },
+ "dest": {
+ "index": "dest_index"
+ }
+ }'
+
+As explain in the Elasticsearch documentation <https://www.elastic.co/guide/en/elasticsearch/reference/6.8/docs-reindex.html#reindex-from-remote>`_, `
+remote hosts have to be explicitly whitelisted in **conf/elasticsearch.yml** using the ``reindex.remote.whitelist`` property.
+
+.. warning::
+
+ Reindexing from a remote Elasticsearch cluster can cause a spike on the Elassandra node executing the reindex query.
+
+.. note::
+
+ The reindex is only supported when reindexing from a remote Elasticsearch cluster. If you need to reindex data from
+ Elassandra, you should use the nodetool rebuild_index utility.
Tooling
_______
-
JMXMP support
-------------
