See on GitHub

    Adding a Database Node

    • When creating a database, you can specify the number of replicas for that database.
      This determines the number of database instances in the database-group.

    • The number of replicas can be dynamically increased even after the database is up and running,
      by adding more nodes to the database-group.

    • The nodes added must already exist in the cluster topology.

    • Once a new node is added to the database-group,
      the cluster assigns a mentor node (from the existing database-group nodes) to update the new node.

    • In this page:

    Add database node - random

    • Use AddDatabaseNodeOperation to add another database-instance to the database-group.
    • The node added will be a random node from the existing cluster nodes. 

    // Create the AddDatabaseNodeOperation
// Add a random node to 'Northwind' database-group
$addDatabaseNodeOp = new AddDatabaseNodeOperation("Northwind");

// Execute the operation by passing it to Maintenance.Server.Send
/** @var DatabasePutResult $result */
$result = $store->maintenance()->server()->send($addDatabaseNodeOp);

// Can access the new topology
$numberOfReplicas = count($result->getTopology()->getMembers());

    Add database node - specific

    • You can specify the node tag to add.
    • This node must already exist in the cluster topology.

    // Create the AddDatabaseNodeOperation
// Add node C to 'Northwind' database-group
$addDatabaseNodeOp = new AddDatabaseNodeOperation("Northwind", "C");

// Execute the operation by passing it to Maintenance.Server.Send
/** @var DatabasePutResult $result */
$result = $store->maintenance()->server()->send($addDatabaseNodeOp);

    Syntax 

    AddDatabaseNodeOperation(?string $databaseName, ?string $nodeTag = null)
    Parameters Type Description
    $databaseName ?string Name of a database for which to add the node.
    $nodeTag ?string Tag of node to add.
    Default: a random node from the existing cluster topology will be added.
    Object returned by Send operation:
    DatabasePutResult    		 Type Description
    $name string Database name
    $topology DatabaseTopology The database topology
    $nodesAddedTo StringArray New nodes added to the cluster topology.
    Will be 0 for this operation.
    $raftCommandIndex int Raft command index

    Home / Docs / Client Api / Operations / Server Wide / Add Database Node