The question of creating a cluster

Hi I am going to organize a cluster of two servers elasticsearch. I would like to clarify some issues.

  • They are among themselves in the realities communicate, store data
  • What will happen if one of the servers will be lost forever
  • How to define that fell elastichsearch rather than the server itself
    In advance thank you

3 is better, see

I'm not really following here sorry, it's probably a language barrier!