From: Martin Skold
Date: August 25 2004 3:05pm
Subject: Re: MySQL cluster and remote datacenters
List-Archive: http://lists.mysql.com/cluster/469
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Hi Brian!

MySQL Cluster has never been intended as an alternative
for applications needing replication over a WAN.
The intra-cluster replication between storage nodes needs
to be on a LAN, preferably with a high-speed interconnect.
Geographic replication over a WAN might still be interesting
for even higher requirements of availability, but this is planned
to be built on an extension of the existing MySQL replication
where you will be able to have several parallel replication links
(multi-master) between two clusters.

BR
-- Martin

Brian Moon wrote:

>> I have been considering a replacement for our mysql databases that
>> receive queries from live internet apps.  mysql replication has
>> demonstrated itself to be much too fragile to maintain, especially
>> across datacenters (private T3 link between).
>
>
> Off list, I would be curious what trouble you have seen and what kind 
> of volume you are dealing with.  We have not had any trouble with this 
> type of thing, but I would like to know if we are headed for it.
>
>> My question is, is it possible to configure mysql cluster with say a
>> configuration like this?
>>
>> Location A                 <-T3->              Location B
>> 2 MySQL API Nodes                              2 MySQL API Nodes
>> 3 Storage Nodes (one also master)              3 Storage Nodes (...)
>
>
> I can't speak for the mysql team, but at the talk I attended at OSCON 
> this was at best thought of as a really, really bad decision.  From 
> what I know, the synchronous nature of the replication between nodes 
> would make for bad delay of data across the T3.
>
> Someone may correct me on this.
>
> Brian Moon
> dealnews.com
>

-- 
Martin Sköld, Software Engineer
MySQL AB, www.mysql.com
Office: +46 (0)730 31 26 21