Configuring Storage Autoscaling for an Instance

Scenarios

You can enable autoscaling for a GaussDB instance so that its storage can be automatically scaled up when the disk usage reaches the specified threshold.

Precautions

• DB instances of the basic edition do not support storage autoscaling. If autoscaling has been enabled for such an instance, the automatic scale-up task will be automatically stopped upon request and autoscaling will be disabled.
• All nodes in the target instance must be in an available state.
• Storage autoscaling is mutually exclusive with the following operations: manually scaling up storage space, adding nodes, changing the disk type, deleting an instance, checking snapshots, updating agents, and storage autoscaling. That is, storage autoscaling cannot be performed when any of the preceding operations is ongoing, even if the autoscaling policy is configured.
• Autoscaling for primary/standby instances is at the instance level.
• Autoscaling for distributed instances is at the shard level.
• If the storage sizes of shards in a distributed instance are different after the scale-up, no shards can be added or deleted until all shards are scaled to the same size.
• During storage autoscaling, the storage space is increased in increments of 40 GB.
  • If the space to increase exceeds the upper limit you have specified, only the space size equal to the upper limit will be increased.
  • If the space to increase exceeds the upper limit specified by the system, only the space size equal to the upper limit will be increased.
• An alarm will be generated when autoscaling fails. This alarm will be automatically cleared when the disk usage is lower than the specified threshold.
• If a yearly/monthly DB instance has pending orders, autoscaling will fail.
• If your account balance is insufficient, autoscaling will fail.

Procedure

1. Log in to the management console.
2. Click in the upper left corner and select a region and project.
3. Click in the upper left corner of the page and choose Databases > GaussDB.
4. On the Instances page, click the name of the target instance to go to the Basic Information page.
5. In the Storage & Backup area, click Auto-Scale.
   Figure 1 Enabling autoscaling
   

6. In the displayed Configure Storage Autoscaling dialog box, set the following parameters:
   Figure 2 Configuring autoscaling
   

   Table 1 Parameters

   Parameter	Description
   Autoscaling	Specifies whether to enable automatic scale-out. By default, automatic scale-out is disabled.
   Trigger If Available Storage Drops To	The storage will be automatically scaled up if the available storage drops to or below the threshold specified by this parameter. The default value is 20%. The value can be 20%, 25%, or 50%.
   Autoscaling Limit	Upper limit of the storage space in GB that can be automatically scaled to. The value of this parameter must be greater than the current storage of the instance. Value range: Primary/Standby instances: [Current storage + 40 GB, 24,000 GB] Distributed instances: [Current storage + 40 GB, 24,000 GB x Number of shards]
   Scaling Method	The value can be By percentage or By fixed size. If By percentage is selected, the storage space to be expanded increases each time. If By fixed size is selected, a fixed volume of storage will be expanded each time. Evaluate your workloads and costs and select a method as required.
   Scale Up By	Size of the storage space to be expanded each time, which depends on the selected scaling method. Storage can be scaled by percentage or fixed size. If By percentage is selected for Scaling Method, the default value of this parameter is 20%, and the value range is [1%, 100%]. If the available storage drops to or below the specified threshold, the storage will be automatically scaled up by a percentage specified by this parameter (in increments of 40 GB). For example, if the current storage space of an instance is 40 GB and this parameter is set to 20%, the volume to be expanded is 8 GB, which will be rounded up to 40 GB. If By fixed size is selected for Scaling Method, the default value of this parameter is 40 GB, and the value range is [40 GB, Current storage space + 40 GB]. If the available storage drops to or below the specified threshold, the storage will be automatically scaled up by a fixed size specified by this parameter.

7. Click OK.