ALTER NODE

Sets and clears node-level configuration parameters on the specified node.

Sets and clears node-level configuration parameters on the specified node. ALTER NODE also performs the following management tasks:

  • Changes the node type.

  • Specifies the network interface of the public network on individual nodes that are used for import and export.

  • Replaces a down node.

For information about removing a node, see

Syntax

ALTER NODE node-name {
    EXPORT ON { network-interface | DEFAULT }
    | [IS] node-type
    | REPLACE [ WITH standby-node ]
    | RESET
    | SET [PARAMETER] parameter=value[,...]
    | CLEAR [PARAMETER] parameter[,...]
}

Parameters

node-name
The name of the node to alter.
[IS] node-type
Changes the node type, where node-type is one of the following:

  • PERMANENT: (default): A node that stores data.

  • EPHEMERAL: A node that is in transition from one type to another—typically, from PERMANENT to either STANDBY or EXECUTE.

  • STANDBY: A node that is reserved to replace any node when it goes down. A standby node stores no segments or data until it is called to replace a down node. When used as a replacement node, Vertica changes its type to PERMANENT. For more information, see Active standby nodes.

  • EXECUTE: A node that is reserved for computation purposes only. An execute node contains no segments or data.

EXPORT ON
Specifies the network to use for importing and exporting data, one of the following:

  • network-interface: The name of a network interface of the public network.

  • DEFAULT: Use the default network interface of the public network, as specified by ALTER DATABASE.

REPLACE [WITH standby-node]
Enterprise Mode only, replaces the specified node with an available active standby node. If you omit the WITH clause, Vertica tries to find a replacement node from the same fault group as the down node.

If you specify a node that is not down, Vertica ignores this statement.

RESET
Enterprise Mode only, restores the specified down node and returns its replacement to standby status. If the down node cannot resume activity, Vertica ignores this statement and leaves the standby node in place.
SET [PARAMETER]
Sets one or more configuration parameters to the specified value at the node level.
CLEAR [PARAMETER]
Clears one or more specified configuration parameters.

Privileges

Superuser

Examples

Specify to use the default network interface of public network on v_vmart_node0001 for import/export operations:

=> ALTER NODE v_vmart_node0001 EXPORT ON DEFAULT;

Replace down node v_vmart_node0001 with an active standby node, then restore it:

=> ALTER NODE v_vmart_node0001 REPLACE WITH standby1;
...
=> ALTER NODE v_vmart_node0001 RESET;

Set and clear configuration parameter MaxClientSessions:

=> ALTER NODE v_vmart_node0001 SET MaxClientSessions = 0;
...
=> ALTER NODE v_vmart_node0001 CLEAR MaxClientSessions;

Set the node type as EPHEMERAL:

=> ALTER NODE v_vmart_node0001 IS EPHEMERAL;