Managing Nodes

You can perform the following operations on individual nodes:

• Starting a Node

• Stopping a Node

• Restarting a Node

Starting a Node

You might need to manually start an HADB node that was stopped because its host was taken off-line for a hardware or software upgrade or replacement. Also, you might need to manually start a node if it fails to restart for some reason (other than a double failure). For more information on how to recover from double failures, see Clearing a database.

In most cases, you should first attempt to start the node using the normal start level. You must use the repair start level if the normal start level fails or times out.

To start a node in the database, use the hadbm startnode command. The syntax is:

hadbm startnode
 [--adminpassword=password | --adminpasswordfile=file]
 [--agent=maurl]
 [--startlevel=level]
 nodeno
 [dbname]

The dbname operand specifies the database name. The default is hadb.

The nodeno operand specifies the number of the node to start. Use hadbm status to display the numbers of all nodes in a database.

For more information, see hadbm-startnode(1).

Start level option

The hadbm startnode command has one special option, --startlevel (short form -l), that specifies the level at which to start the node.

Node start levels are:

• normal (default): starts the node with the data found locally on the node (in the memory and in the data device file on the disk) and synchronizes it with the mirror for recent updates it missed.

• repair: forces the node to discard local data and copy it from its mirror.

• clear: reinitializes the devices for the node and forces a repair of data from its mirror node. Use when the device files need to be initialized, necessary if they are damaged or the disk that contained the device files is replaced.

See General Options for a description of other command options.

Example 3–6 Example of starting a node

hadbm startnode 1

Stopping a Node

You might need to stop a node to repair or upgrade the host machine’s hardware or software. To stop a node, use the hadbm stopnode command. The command syntax is:

hadbm stopnode  
[--adminpassword=password | --adminpasswordfile=file]  
[--agent=maurl]  
[--no-repair]  
nodeno  
[dbname]

The nodeno operand specifies the number of the node to stop. The mirror node of this node number must be running. Use hadbm status to display the numbers of all nodes in a database.

The dbname operand specifies the database name. The default is hadb.

The hadbm stopnode command has one special option, --no-repair (short form -R) that indicates no spare node is to replace the stopped node. Without this option, a spare node starts up and takes over the functioning of the stopped node.

See General Options for a description of other command options. For more information, see hadbm-stopnode(1).

Example 3–7 Example of stopping a node

hadbm stopnode 1

Restarting a Node

You might have to restart a node if you notice unusual behavior such as excessive CPU consumption.

To restart a node in the database, use the hadbm restartnode command. The command syntax is:

hadbm restartnode  
[--adminpassword=password | --adminpasswordfile=file]  
[--agent=maurl]  
[--startlevel=level]  
nodeno  
[dbname]

The dbname operand specifies the database name. The default is hadb.

The nodeno operand specifies the number of the node to restart. Use hadbm status to display the numbers of all nodes in a database.

The hadbm restartnode command has one special option, --startlevel (short form -l), that specifies the level at which to start the node. See Start level option for more information.

See General Options for a description of other command options. For more information, see hadbm-restartnode(1).

Example 3–8 Example of restarting a node

hadbm restartnode 1