write data in another drupal website / rest I need to implement the following setup:
- master site (drupal 7)
- child site (drupal 7)

User create/update nodes in the master site. Then the nodes should be copied to some child sites, depending on some selections. The records in the child site should be updated if they already exist. Also deleting should be possible. These sites are hosted at another hoster than the master website.

I was doing some research and found among other techniques the REST Services.
Did I understand right, that with the REST services I can implement what I want? Or are there better alternatives?

thanks for any help
Try the following modules.

Drupal Sync


  This module allows synchronizing content among multiple websites.
  Supported entity types: node and taxonomy, menu items.
  
  Many hooks were used during creation of the module. It allows widening synchronization functional by developing additional modules.


Deploy


  The Deploy module is designed to allow users to easily stage content from one Drupal site to another. Deploy automatically manages dependencies between entities (like node references). It is designed to have a rich API which can be easily extended to be used in a variety of content staging situations.