title: Cassandra LWT ReadTimeoutException or WriteTimeoutException
body: <p>I am trying to have two process insert in the same table. So first I try to enter the partition and clustering key values with a LWT if this succeeds it means the process can continue with that work for that time bucket otherwise another process already completed that bucket. 
  The LWT is set with a consistency level of One and a serial consistency level of LOCAL_SERIAL. </p>
  
  <p>If the first insert success the work is done and another insert is done with also a consistency level of one. The first statement has a TTL statement for the case where the process doing the work terminates in the middle the row will be empty after a TTL of 90.</p>
  
  <p>Even if I run a single process the LWT fails with either a read or write timeout exception.</p>
  
  <p>Here is the prepared statement and the exceptions I am getting. Any help is appreciated.</p>
  
  <pre><code>com.datastax.driver.core.exceptions.ReadTimeoutException: 
  Cassandra timeout during read query at consistency LOCAL_QUORUM 
  (2 responses were required but only 1 replica responded)
  
  com.datastax.driver.core.exceptions.WriteTimeoutException: 
  Cassandra timeout during write query at consistency LOCAL_SERIAL 
  (2 replica were required but only 1 acknowledged the write)
  
  statement = {DefaultPreparedStatement@10844} 
   preparedId = {PreparedId@10886} 
   query = "INSERT INTO event_store(evt_type, rcncl_date, rcncl_ts) values( ?, ?, ?) IF NOT EXISTS USING TTL 90;"
   queryKeyspace = "test"
   routingKey = null
   consistency = {ConsistencyLevel@10882} "ONE"
   serialConsistency = {ConsistencyLevel@10883} "LOCAL_SERIAL"
   traceQuery = false
   retryPolicy = null
  </code></pre>