title: Cassandra read latencies
body: <p>What is the difference between these read latency metrics?</p>
  
  <pre><code>org.apache.cassandra.metrics.ClientRequest.Read.Latency
  org.apache.cassandra.metrics.ColumnFamily.system.batchlog.ReadLatency
  org.apache.cassandra.metrics.ColumnFamily.system.batchlog.CoordinatorReadLatency
  org.apache.cassandra.metrics.ColumnFamily.system.batchlog.CoordinatorScanLatency
  </code></pre>