master slave crashing daily
First you should check the error logs &amp; post for clarification.
This can happen doue to-

Your slave database is differ to its master when replication start. 
So before replication sync both the server. 


If your replication is statement type &amp; replicate some specific database. ex-

use not_replica;
alter table replica.test ....
use replica;
insert into replica.test ...


here alter command for test would not replicate. because you are using not_replica database. after that insert statement would fail &amp; replication stopped.