can I have one server, which is slave for like 500 masters? All the masters have different content, but they inserting is like once per minute, so I think 8 core slave should be sufficient for it.
And also can I have one master database on this slave server? I don't have to, but it would reduce our servers costs.
Thanks for answering!
I don't know about "500", but there is "multi-source" replication in recent versions of MySQL, plus MariaDB.
So that is 500 inserts per minute on the Slave? 8/second is no problem. Even 1 core would not be taxed. Even if all inserts went into the same table.
Even if multi-source did not let you have 500, you could put, say, 25 instances of MySQL on a single server, each receiving data from 20 Masters.