Elasticsearch JDBC River Communications link failure

Question

I am using Elasticsearch 1.3.0 in production cluster. ( I know river has been deprecated in latest version (2.0)) . Since few days I am getting error Communications link failure. I tried with increasing query_timeout. Is there any way we can fix this at river end.

Stack Trace:

Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet successfully received from the server was 500,000 milliseconds ago.  The last packet sent successfully to the server was 500
,010 milliseconds ago.
        at sun.reflect.GeneratedConstructorAccessor118.newInstance(Unknown Source)
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
        at com.mysql.jdbc.Util.handleNewInstance(Util.java:408)
        at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1137)
        at com.mysql.jdbc.MysqlIO.readPacket(MysqlIO.java:673)
        at com.mysql.jdbc.MysqlIO.getResultSet(MysqlIO.java:427)
        at com.mysql.jdbc.MysqlIO.readResultsForQueryOrUpdate(MysqlIO.java:3222)
        at com.mysql.jdbc.MysqlIO.readAllResults(MysqlIO.java:2393)
        at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2816)
        at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2820)
        at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2769)
        at com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1569)
        at org.xbib.elasticsearch.river.jdbc.strategy.simple.SimpleRiverSource.executeQuery(SimpleRiverSource.java:587)
        at org.xbib.elasticsearch.river.jdbc.strategy.simple.SimpleRiverSource.execute(SimpleRiverSource.java:318)
        at org.xbib.elasticsearch.river.jdbc.strategy.simple.SimpleRiverSource.fetch(SimpleRiverSource.java:287)
        ... 10 more

My river command look like.

        {
            "type": "jdbc",
            "jdbc": {
                "strategy": "simple",
                "fetchsize": "50",
                "driver": "com.mysql.jdbc.Driver",
                "url": "jdbc:mysql://localhost:3306/mydb",
                "user": "root",
                "password": "",
                "sql": [{
                    "statement": "select * from table"
                }],
                "index": "index",
                "type": "type",
                "schedule": "0 */59 0-23 ? * ** *",
                "query_timeout": 5400
            },
            "index": {
                "index": "index",
                "type": "type",
                "versioning": false
            }
        }