title: Hadoop - Large files in distributed cache
body: <p>I have a 4 GB file that I am trying to share across all mappers through a distributed cache. But I am observing a significant delay in map task attempt starts. Specifically, there is a significant delay between the time I submit my job (through job.waitForCompletion()) and the time the first map starts.</p>
  
  <p>I would like to know what the side effect of having large files in a DistributedCache. How many times is the file on a distributed cache replicated ? Does the number of nodes in a cluster have any effect on this ? </p>
  
  <p>(My cluster has about 13 nodes running on very powerful machines where each machine is able to host close to 10 map slots.)</p>
  
  <p>Thanks</p>