SQL Node clarification

[Shaheeb Roshan]

Hello,

I realize that this question has been asked and answered a few times, but I'm still not comfortable. Does the following setup make sense:

Server 1: SQL Node + Data Node
Server 2: SQL Node + Data Node
Server 3: MGM Node

Servers 1&2 are identical with adequate RAM. Server 3 contains my application middleware in addition to serving as the managment node.

Does the above setup offer high availability? So if Server 1 fails (hardware fails or os crashes), will I still have uninterrupted functionality/access to my data? If no, then why not?

If yes, I don't quite understand how to tell my application which mysql server to query.

Is there a way to present a single IP address or hostname to my application that will then query against any available nodes in the cluster? Do I have to use a separate technology like a director (maybe ldirectord) to accomplish this? If so, then what is the advantage of Mysql Cluster in the HA context? Can I not achieve the same net result with replication, a director and heartbeats from the servers?

And finally I'd just like to note that this community is very impressive in its technical contribution. I've found answers to a lot of (seemingly) unique and complex problems. I hope this time is no different!


Shaheeb Roshan
MRS Inc.