# Instances

## Create a new instance

    // Create an empty object
    $instance = $service->instance();

    // Send to the API
    $instance->create(array(
        'name'   => '{name}',
        'flavor' => $service->flavor('{flavorId}'),
        'volume' => array('size' => 4)               // 4GB of volume disk
    ));

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### Waiting for the instance to build

The SDK provides a blocking operation that will wait until your instance resource has transitioned into an `ACTIVE` state. During this period, it will continuously poll the API and break the loop when the state has been achieved:

    $instance->waitFor('ACTIVE', null, function ($instance) {
        // This will be executed continuously
        printf("Database instance build status: %s\n", $instance->status);
    });

### Connecting an instance to a load balancer

The instance created in the previous step can only be accessed from the Rackspace private network (aka `SERVICENET`). If you have a cloud server instance in the same region as the database server instance, you will be able to connect to the database from that cloud server instance.

If, however, you would like to access the database from the Internet, you will need to create a load balancer with an IP address that is routable from the Internet and attach the database server instance as a back-end node of this load balancer.

    $lbService = $client->loadBalancerService(null, '{region}');

    // Create empty object
    $loadBalancer = $lbService->loadBalancer();

    // Associate this LB with the instance as a "node"
    $loadBalancer->addNode($instance->hostname, 3306);
    $loadBalancer->addVirtualIp('PUBLIC');

    // Configure other parameters and send to the API
    $loadBalancer->create(array(
      'name'     => 'DB Load Balancer',
      'port'     => 3306,
      'protocol' => 'MYSQL',
    ));

    // Wait for the resource to create
    $loadBalancer->waitFor('ACTIVE', null, function ($loadBalancer) {
        printf("Load balancer build status: %s\n", $loadBalancer->status);
    });

    foreach ($loadBalancer->virtualIps as $vip) {
        if ($vip->type == 'PUBLIC') {
            printf("Load balancer public %s address: %s\n", $vip->ipVersion, $vip->address);
        }
    }

In the example above, a load balancer is created with the database server instance as its only back-end node. Further, this load balancer is configured to listen for MySQL connections on port 3306. Finally a virtual IP address (VIP) is configured in the `PUBLIC` network address space so that this load balancer may receive connections from the Internet.

Once the load balancer is created and becomes `ACTIVE`, it’s Internet-accessible IP addresses are printed out. If you connect to any of these IP addresses on port 3306 using the MySQL protocol, you will be connected to the database created in step 3.

## Retrieving an instance

    $instance = $service->instance('{instanceId}');

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## Updating an instance

An instance can be updated to use a specific configuration as shown below.

    $instance->update(array(
        'configuration' => '{configurationId}'
    ));

Note

If any parameters in the associated configuration require a restart, then you will need to restart the instance after the update.

## Deleting an instance

    $instance->delete();

## Restarting an instance

    $instance->restart();

## Resizing an instance’s RAM

To change the amount of RAM allocated to the instance:

    $flavor = $service->flavor('{flavorId}');
    $instance->resize($flavor);

## Resizing an instance’s volume

You can also independently change the volume size to increase the disk space:

    // Increase to 8GB disk
    $instance->resizeVolume(8);