I have some questions regarding elastic search cluster ?

The setup

  1. I had started a elastic search instance (A) in a machine.
  2. Had inserted all data into it.
  3. Set the number of master nodes to 2
  4. Started two elastic search instances (B & C) in two other machines

Closing A, does not enable me to continue with search from B or C

a) Do I need to replicate data in all the machines?
b) Do I need to setup the whole cluster before inserting data?
c) A user will want to have a single url for the search (he should not bother whether, the master went down or not, ie failover must be transperanet). How to achieve this ?
d) Is there a step by step guide for setting up elastic search cluster ?