h1. How long will be down time when setting up replication

The process of configuration of [[MySQL replication]] from working master host to slave host is performed in this sequence:

1. +Switch master host to replication mode+.
   For this need to restart all services of a system.
   The estimated down time is ~10 sec, while services are restarted.
   Work time: 5 minutes.

2. +Enable protection from database changes on master host+.
  After this users won't be able to make configuration changes of the system.
  The calls will continue to pass.
  CDR and [[Balances]] won't be updated.
  CDR and balance information will be accumulated in temporary database.
  Down time is not expected.
  Work time: 10 sec.

3. +Copy database from master host to slave host+.
  During copy time, limitations described in i.2 will persist.
  Down time is not expected.
  Work time: depends on network bandwidth between master and slave host and database size.

4. +Disable protection from database changes on master host+.
   System on master host returns to regular work mode.
   Accumulated CDRs automatically transfer to main database from temporary. 
   Time which is needed for full CDR transfer: depends of quantity of accumulated CDRs in temporary database and CPU load.
   Down time is not expected.
   Work time: 10 sec.

5. +Launch replication on slave host+.
   Down time is not expected.
   Work time: 5 minutes.

[[Сколько будет простой при настройке репликации|Русский перевод]]