failover and load balancing
Fajar A. Nugraha
fajar at fajar.net
Thu Apr 23 05:20:05 CEST 2009
On Wed, Apr 22, 2009 at 8:43 PM, Uwe Kastens <kiste at kiste.org> wrote:
>>> The problem with master master for
>>> mysql is, that you have to resync each time you are dropping a table, a
>>> view etc.pp.
No you don't.
When setup correctly, all SQL statement on one node will be executed
on the other node as well. That includes DDL like creating/dropping
table, or adding/removing users.
An exception is if you EXPLICITLY don't replicate changes to mysql
schema. In that case what you say might be true.
>> It depends on what you are doing. If you want to read out you user database
>> for authentication you are right. But If you want to write accouting you have
>> a lot of writes. I have seen up to 300 writes/sec for a small national
If you have enough memory then with Innodb engine on MySQL you can
easily serve all reads from Innodb buffer pool (a.k.a. memory cache).
That way only writes will be disk-bound. My db currently handles over
100k reads/s, mostly served from buufer pool.
That way I only need to scale the disk enough to handle writes
(currently around several hundred writes/s)
> I would prefer to have some fallback solution to write data to a flat
> file if the database is offline (which should be a question of minutes
> or an hour) and import it later on.
which is what buffered-sql does for acct.
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