title: Cassandra Write Time out error and no rollback occured
body: <p>I have one node with replication factor 1 and fire a batch statement query on that node ,cassandra writes the data but failed to acknowledge with in timeout limit . then it gives a write timout exception with following stacktrace .</p>
  
  <pre><code>failed `Exception in thread "main" com.datastax.driver.core.exceptions.WriteTimeoutException: Cassandra timeout during write query at consistency ONE (1 replica were required but only 0 acknowledged the write)
      at com.datastax.driver.core.exceptions.WriteTimeoutException.copy(WriteTimeoutException.java:54)
      at com.datastax.driver.core.ResultSetFuture.extractCauseFromExecutionException(ResultSetFuture.java:271)
      at com.datastax.driver.core.ResultSetFuture.getUninterruptibly(ResultSetFuture.java:187)
      at com.datastax.driver.core.Session.execute(Session.java:126)
      at jason.Stats.analyseLogMessages(Stats.java:91)
      at jason.Stats.main(Stats.java:48) 
  </code></pre>
  
  <p>then if you go back and check the table then you will find data has been written . So my question is , if cassandra gives write timout exception then it should rollback the changes .
  I mean i don't want to write to database if i am getting write timout exception ,is there any rollback strategy present for that particular scenario .</p>