Elasticsearch indexing is very slow - elasticsearch

Question

I have a Titan database with Cassandra storage backend, and I am trying to create a mixed index based on two property keys.
I am able to register the Index using following commands:
graph=TitanFactory.open(config);
graph.tx().rollback()
m = graph.openManagement();
m.buildIndex("titleBodyMixed", Vertex.class).addKey(m.getPropertyKey("title")).addKey(m.getPropertyKey("body")).buildMixedIndex("search");
m.commit();
m.awaitGraphIndexStatus(graph, 'titleBodyMixed').status(SchemaStatus.REGISTERED).timeout(3, java.time.temporal.ChronoUnit.MINUTES).call();
And when I am checking, the Index is successfully registered after a few seconds. At next step, I try to reindex the database using the following commands:
m = graph.openManagement();
m.updateIndex(m.getGraphIndex('titleBodyMixed'), SchemaAction.REINDEX).get();
However, updateIndex command is not finishing, (After 12 hours).
I have about 300k data entry in the database and each data entry has one Title and one Body to index.
My question is that how can I speed up the indexing?
When I am using top command I see that my CPU is not saturated by indexing processes:
My Titan config file is as bellow:
config =new BaseConfiguration();
config.setProperty("storage.backend","cassandra");
config.setProperty("storage.hostname", "127.0.0.1");
config.setProperty("storage.cassandra.keyspace", "smartgraph");
config.setProperty("index.search.elasticsearch.interface", "NODE");
config.setProperty("index.search.backend", "elasticsearch");
The following is showing elasticsearch service properties:
curl -X GET 'http://localhost:9200'
{
"status" : 200,
"name" : "Ms. Marvel",
"cluster_name" : "elasticsearch",
"version" : {
"number" : "1.7.2",
"build_hash" : "e43676b1385b8125d647f593f7202acbd816e8ec",
"build_timestamp" : "2015-09-14T09:49:53Z",
"build_snapshot" : false,
"lucene_version" : "4.10.4"
},
"tagline" : "You Know, for Search"
}

Answer 1

The idea is, the index reindexing process will not start unless all sessions are closed. You most probably have sessions open with the database. Therefore, the reindex job is never triggered.
With this Gremlin script, you could close all sessions. You should see that the indexing will take place afterwards.
Will that help?