Re: Cluster Configuration 2 MGMD nodes

[Larry Davis]

Has anyone been able to successfully get this working (on a 4.1 system) ? I've gone through the docs and the forums and I haven't found any definitive answer to what I would think is a common issue.

To provide increased availability, i would like to set up dual mgmd nodes. I have 2 hosts used for the ndb data nodes as well as the sql nodes. I have 2 separate machines I want to use as my mgmd nodes. Following the configuration guidelines, my config.ini files looks as such :

# Declare our defaults
[NDBD DEFAULT]
NoOfReplicas=2
datadir=/var/lib/mysql-cluster

[MYSQLD DEFAULT]

[NDB_MGMD DEFAULT]
datadir=/var/lib/mysql-cluster

[TCP DEFAULT]

# Primary Mgmt Server
[NDB_MGMD]
Id= 1
ArbitrationRank= 1
hostname=192.168.1.22

# Backup Mgmt Server
[NDB_MGMD]
Id= 2
ArbitrationRank= 2
hostname=192.168.1.156

[NDBD]
id=3
hostname=192.168.1.152

[NDBD]
id=4
hostname=192.168.1.157

# We need fillers to indicate that we have 2 sql nodes
[MYSQLD]
id=5
hostname=192.168.1.152
ArbitrationRank: 0

[MYSQLD]
id=6
hostname=192.168.1.157
ArbitrationRank: 0

In my /etc/my.cnf file, i have :
[mysqld]
ndbcluster
ndb-connectstring=192.168.1.22,192.168.1.156

[mysql_cluster]
ndb-connectstring=192.168.1.22,192.168.1.156


When I start up the cluster, I can see the following :

On the primary :
Connected to Management Server at: localhost:1186
Cluster Configuration
---------------------
[ndbd(NDB)] 2 node(s)
id=3 @192.168.1.152 (Version: 4.1.16, Nodegroup: 0, Master)
id=4 @192.168.1.157 (Version: 4.1.16, Nodegroup: 0)

[ndb_mgmd(MGM)] 2 node(s)
id=1 @192.168.1.22 (Version: 4.1.16)
id=2 (not connected, accepting connect from 192.168.1.156)

[mysqld(API)] 2 node(s)
id=5 @192.168.1.152 (Version: 4.1.16)
id=6 @192.168.1.157 (Version: 4.1.16)

On the backup :
ndb_mgm> show
Cluster Configuration
---------------------
[ndbd(NDB)] 2 node(s)
id=3 (not connected, accepting connect from 192.168.1.152)
id=4 (not connected, accepting connect from 192.168.1.157)

[ndb_mgmd(MGM)] 2 node(s)
id=1 (not connected, accepting connect from 192.168.1.22)
id=2 @192.168.1.156 (Version: 4.1.16)

[mysqld(API)] 2 node(s)
id=5 (not connected, accepting connect from any host)
id=6 (not connected, accepting connect from any host)

Now, seeing as this is the backup, i am thinking that this is okay. However, I shutdown the cluster, then start the mgmd on the backup only and then restart the ndb's and mysqld' but i still don't see them connecting to the backup.

Looking at the ndb log files, it looks like they are connecting to the backup :
2006-01-13 16:19:27 [ndbd] INFO -- Version 4.1.16 --
2006-01-13 16:19:27 [ndbd] INFO -- Configuration fetched at 192.168.1.156 port 1186

but i cannot manage them from the backup mgmd nor do the nodes look like they are actually connected. Can anyone shed some light on this ?