2 messages in com.mysql.lists.clusterRe: mysql cluster 4 data nodes
FromSent OnAttachments
Shirish Ojha20 Jul 2006 13:46 
Mikael Ronström20 Jul 2006 15:41 
Subject:Re: mysql cluster 4 data nodes
From:Mikael Ronström (mik@mysql.com)
Date:07/20/2006 03:41:59 PM
List:com.mysql.lists.cluster

Hi,

I think you're mixing the role of primary replica and master. There is only one master in a cluster. This node has specific roles in many protocols. Within a node group there is no special designation of nodes, they are all equal. Each fragment of a table will have its primary replica stored on one node in a node group and backup replicas on the remaining nodes. Different fragments can have different primary replica nodes.

Rgrds Mikael

2006-07-20 kl. 22.47 skrev Shirish Ojha:

Hi,

This is the 4 node cluster whcih we have set up

ndb_mgm> show Cluster Configuration

--------------------- [ndbd(NDB)] 4 node(s) id=2 @10.4.16.45 (Version: 5.0.22, Nodegroup: 0, Master) id=3 @10.4.16.42 (Version: 5.0.22, Nodegroup: 0) id=4 @10.4.16.43 (Version: 5.0.22, Nodegroup: 1) id=5 @10.4.16.44 (Version: 5.0.22, Nodegroup: 1)

[ndb_mgmd(MGM)] 1 node(s) id=1 @10.4.16.40 (Version: 5.0.22)

[mysqld(API)] 2 node(s) id=6 @10.4.16.41 (Version: 5.0.22) id=7 (not connected, accepting connect from any host)

This is our config.ini

cat config.ini [NDBD DEFAULT] NoOfReplicas=2 DataDir= /var/lib/mysql-cluster [NDB_MGMD DEFAULT] # Managment Server [NDB_MGMD] # the IP of THIS SERVER HostName=10.4.16.40 DataDir= /var/lib/mysql-cluster # Storage Engines [NDBD] # the IP of the FIRST SERVER (STORAGE NODE) HostName=10.4.16.45 [NDBD] # the IP of the SECOND SERVER (STORAGE NODE) HostName=10.4.16.42 [NDBD] # the IP of the THIRD SERVER (STORAGE NODE) HostName=10.4.16.43 [NDBD] # the IP of the FOURTH SERVER (STORAGE NODE) HostName=10.4.16.44 # 2 MySQL Clients # I personally leave this blank to allow rapid changes of the mysql clients; # you can enter the hostnames of the above two servers here. I suggest you dont. [MYSQLD] # the IP of the MYSQL SERVER (MYSQL NODE) HostName=10.4.16.41 [MYSQLD]

My question is ===============

as the number of replica is 2 and thus correctly it shows as 2 node groups BUT

shouldn't each node has a separate master

AT present, it is showing only one node as master ( and in my view 2 nodes ( one from each node group, should be shown as master)

id=2 @10.4.16.45 (Version: 5.0.22, Nodegroup: 0, Master) id=3 @10.4.16.42 (Version: 5.0.22, Nodegroup: 0) id=4 @10.4.16.43 (Version: 5.0.22, Nodegroup: 1) id=5 @10.4.16.44 (Version: 5.0.22, Nodegroup: 1)

Thanks Shirish

Mikael Ronstrom, Senior Software Architect MySQL AB, www.mysql.com

Jumpstart your cluster: http://www.mysql.com/consulting/packaged/cluster.html My blog: http://mikaelronstrom.blogspot.com