Hi Andreas,
with NDB, you have 3 types of node: SQL which is mysqld, Management
running ndb_mgmd and data running ndbmtd. SQL and Management can be on
the same physical host (cohosting) but you ideally need 2 for HA, the
ndb_mgmd process is very small and low on resources. Data nodes, for HA
you need mandatory 2 hosts and they can't be on the same host as the
Management node. The Data nodes need a lot of memory since in most
application, you'll want to use only in memory data (with async persistence)
So, the classic setup is:
2 servers, low memory, SQL + Mgmnt
2 servers, high memory, data
Regards,
Yves
On 12-02-09 03:21 AM, Stallmann, Andreas wrote:
Hi Yves,
ØNDB requires a minimum of 4 nodes for HA...
I understood that in NDB-Cluster the concept of „nodes” has nothing to
do with physical (or virtual) hosts but with running instances /
processes. That’s at least, what can be derived from
http://www.howtoforge.com/setting-up-a-loadbalanced-mysql-cluster-with-mysql5.1
and from http://dev.mysql.com/doc/refman/5.1/en/mysql-cluster-overview.html.
Too me it looks as if NDB-Cluster is supposed to be set up as a (n>1)+1
cluster*, where the n>1 hosts can carry mysqld and ndb and the +1 host
is supposed to carry the mysql cluster manager. Please correct me, if
I’m wrong of if this setup is possible, but (for some reason) is unwise
/ unstable / unsuitable for productive usage.
Thanks in advance,
Andreas
*The first links speaks of an loadbalanced mysql cluster and thus needs
two further nodes, which carry the load balancing software.
----------------------------
CONET Solutions GmbH, Theodor-Heuss-Allee 19, 53773 Hennef.
Registergericht/Registration Court: Amtsgericht Siegburg (HRB Nr. 9136)
Geschäftsführer/Managing Director: Anke Höfer
----------------------------
_______________________________________________
Pacemaker mailing list: Pacemaker@oss.clusterlabs.org
http://oss.clusterlabs.org/mailman/listinfo/pacemaker
Project Home: http://www.clusterlabs.org
Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf
Bugs: http://bugs.clusterlabs.org
_______________________________________________
Pacemaker mailing list: Pacemaker@oss.clusterlabs.org
http://oss.clusterlabs.org/mailman/listinfo/pacemaker
Project Home: http://www.clusterlabs.org
Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf
Bugs: http://bugs.clusterlabs.org
