Data Transmission Service:Create a DTS dedicated cluster

Prerequisites

Your Alibaba Cloud account is assigned the system default role AliyunDTSDefaultRole if you want to create a DTS dedicated cluster as a Resource Access Management (RAM) user. Then, you can grant the AliyunDTSFullAccess permission to the RAM user by using your Alibaba Cloud account.

Benefits

You can create only data migration, data synchronization, and change tracking tasks in DTS dedicated clusters. DTS dedicated clusters have the following benefits:

• DTS dedicated clusters provide independent resources that are isolated from the resources used by DTS instances of other users. The DTS instances created in your DTS dedicated clusters can never be affected by the DTS instances of other users. In addition, you can control the loads of your DTS dedicated clusters to enhance the stability of your business.

• In a DTS dedicated cluster, you can allocate the resources of the entire cluster to a single DTS instance to improve the performance of the DTS instance. This allows you to write large amounts of data to the source database and synchronize the data to the destination database in real time.

• You are charged only for the resources of DTS dedicated clusters. You do not need to pay fees when you create DTS instances in the clusters. The cost is further reduced if you enable the overcommitment mode for a DTS dedicated cluster, compared with the cost of purchasing a large number of DTS instances.

Limits

• DTS dedicated clusters support only the subscription billing method. You must pay when you create a DTS dedicated cluster.

• You are charged only for the resources of DTS dedicated clusters. You do not need to pay fees when you create DTS instances in the clusters.

• DTS dedicated clusters can be created only in the following regions: China (Hangzhou), China (Shanghai), China (Beijing), China (Zhangjiakou), China (Hohhot), China (Ulanqab), China (Shenzhen), China (Guangzhou), China (Chengdu), China (Hong Kong), Singapore, Japan (Tokyo), US (Virginia), and Germany (Frankfurt).

• If you want to configure a data synchronization task in a DTS dedicated cluster, the source database, destination database, and DTS dedicated cluster must reside in the same region.

• The number of nodes and the size of disks in a DTS dedicated cluster cannot be reduced.

• You can create up to five DTS dedicated clusters in a single region. If you need to create more than five DTS dedicated clusters in a region, contact Alibaba Cloud technical support to add your account to the whitelist for creating more DTS dedicated clusters.

  Note

  We recommend that you create two or more DTS dedicated clusters to implement disaster recovery. Make sure that the available resources, such as the CPU, memory, disks, and DTS units (DUs), in a cluster are greater than 1/N. Otherwise, switchovers may fail due to insufficient hardware resources. N is the number of nodes in a cluster. For example, if you have three nodes in a cluster, the available resources must be greater than one-third of the total resources of the cluster.

• If the usage of resources in a DTS dedicated cluster, such as CPU, memory, and disks, exceeds 80%, you must scale up the cluster at the earliest opportunity. The task failures or switchover failures caused by insufficient resources are not covered by the Service Level Agreement of DTS.

• After a DTS dedicated cluster is created, the system reserves 5% of the disk space for defragmentation and to ensure that the system runs properly even if the disk is full.

Billing

For more information about the billing of DTS dedicated clusters, see Billing of DTS dedicated clusters.

Procedure

1. Go to the Dedicated Cluster page.

2. In the top navigation bar, select the region in which you want to create a DTS dedicated cluster from the drop-down list to the right of Workbench.

3. Click Create Dedicated Cluster below Cluster Task.

4. Configure the following parameters based on your business requirements:

   Parameter	Description
   Billing Method	The billing method of the cluster. Select Subscription.
   Cluster Type of DTS Instance	The type of the cluster. Select Dedicated Cluster.
   Region	The region in which the cluster resides. Note The region of a DTS dedicated cluster cannot be changed after the cluster is created.
   Dedicated Cluster	This parameter is set to Data Migration, Data Synchronization, and Change Tracking. You cannot change the value of this parameter.
   Specification of Dedicated Cluster Nodes	This parameter is set to 15 DTS Units. You cannot change the value of this parameter. Note DTS dedicated clusters support only the node specifications of 15 DUs. A DU indicates the minimum hardware resources that are required to run a DTS task. 15 DUs indicate that you can configure up to 15 DTS tasks on a single node that is not overcommitted. The hardware resources allocated to each DTS task are isolated from each other. You can also allocate multiple DUs to a single DTS task. You can enable the overcommitment mode for a DTS dedicated cluster. For more information, see Set an overcommit ratio for a DTS dedicated cluster. If Overcommit Ratio is set to 200%, the number of DUs on a node is increased from 15 to 30, whereas the actual number of DUs of hardware resources remains at 15. This way, you can configure up to 30 DTS tasks on a single node. However, if the overcommitment mode is enabled, hardware resource contention occurs among DTS tasks, and each DTS task may obtain only 50% of the hardware resources that the task could obtain when overcommitment is disabled. Therefore, we recommend that you enable the overcommitment mode only in the following scenarios: The amount of incremental data to be synchronized is small. Data synchronization tasks run in different time periods. For information about the comparison between specifications of DTS dedicated clusters and public clusters, see Migrate a DTS instance between a dedicated cluster and a public cluster.
   Storage Space of Dedicated Cluster Node	The storage space of each node in the DTS dedicated cluster. Valid values: 1024 to 30720. Unit: GB. The value must be increased in increments of 512 GB. Note After a DTS dedicated cluster is created, you can increase the disk space of nodes to improve the storage capacity of the cluster. For more information, see Increase the storage space of nodes in a DTS dedicated cluster.
   Destination Region	By default, the value of this parameter is the same as the value of Region and cannot be changed.
   Resource Group	In this example, you do not need to configure this parameter. For more information, see What is Resource Management?
   Order Time	The subscription duration. Valid values: 1 to 9 Months, 1 Year, 2 Years, and 3 Years. Important If you want to enable auto-renewal for the cluster, select Auto-renewal. Make sure that you have sufficient balance within your account before the system automatically renews the cluster.
   Nodes in a Dedicated Cluster	The number of nodes in the DTS dedicated cluster. Default value: 2. Valid values: 2 to 100. Note When you purchase a DTS dedicated cluster, you must select at least two nodes to implement disaster recovery. After a DTS dedicated cluster is created, you can add more nodes to the cluster. For more information, see Scale out a DTS dedicated cluster.

5. Purchase the DTS dedicated cluster.

   1. Click Buy Now.

   2. On the Confirm Order page, view the configurations, read and select Terms of Service.

   3. Click Pay. On the Purchase page, complete the payment as prompted.

      Note

      You can also click Add to Cart to purchase the DTS dedicated cluster together with other services. For more information, see the Pay for services in the cart section of this topic.

6. Check whether the DTS dedicated cluster is created.

   1. After you complete the payment, click Console to go to the DTS console.

   2. In the left-side navigation pane, click Dedicated Cluster.

   3. In the top navigation bar, select the region in which the DTS dedicated cluster resides.

   4. Check whether the DTS dedicated cluster that you just created is in the cluster list.

      • If the DTS dedicated cluster is displayed, the cluster is created. If the DTS dedicated cluster is in the Running state, the cluster is created and initialized.

      • If the DTS dedicated cluster is not displayed, wait for 1 to 5 minutes and then refresh the page. If the DTS dedicated cluster is still not displayed, check whether the issues that are described in the following table occur. If none of the issues occur, contact Alibaba Cloud technical support.

        The following table describes the possible causes and solutions if you cannot find a DTS dedicated cluster in the cluster list.

        Possible cause	Solution
        The DTS dedicated cluster does not belong to the region that you select.	In the top navigation bar, select the region in which the DTS dedicated cluster resides.
        The DTS dedicated cluster fails to be created due to insufficient resources.	A DTS dedicated cluster may fail to be created due to insufficient resources. In this case, the fees that you paid for the DTS dedicated cluster are refunded. Go to the Expenses and Costs console. In the left-side navigation pane, choose Cost Management > Orders. On the Orders page, you can check whether you receive the refund.

Pay for services in the cart

After you configure a subscription DTS dedicated cluster, you can click Add to Cart to purchase the cluster together with other services. You can perform the following steps to pay for orders in the cart:

1. On the right side of the page, click the Cart icon.

2. In the Cart panel, select the services that you want to purchase and click Proceed to Checkout.

3. On the Cart page, check whether the services that you want to purchase are selected.

   • If the services that you want to purchase are selected, click Buy Now.

   • If the services that you want to purchase are not selected, select the services and click Buy Now.

4. On the Confirm Order page, read and select Terms of Service and click Pay.

5. On the Purchase page, complete the payment as prompted.