When multiple teams share a DTS public cluster, resource contention from other tenants can degrade migration throughput and destabilize long-running synchronization tasks. A DTS dedicated cluster gives you a pool of Elastic Compute Service (ECS) instances of the same specifications, deployed in a single region and reserved exclusively for your Data Transmission Service (DTS) workloads. You control resource allocation, cluster load, and task scheduling—eliminating cross-tenant interference.
Benefits
Exclusive resources and high stability
Each DTS task in a dedicated cluster gets isolated hardware resources. Workloads from other users never affect your tasks. Because you control the cluster load, you can tune throughput and stability to match your business requirements.
High performance
A dedicated cluster lets you allocate the full resources of the cluster to a single DTS task. This makes it practical to write large volumes of data to the source database and replicate changes to the destination in real time.
Reduced costs
You pay only for cluster resources, not for individual DTS instances created within the cluster. Enabling overcommitment mode lets you provision more concurrent tasks per node, lowering the effective cost per task compared with purchasing a large number of individual DTS instances.
Key concepts
| Concept | Description |
|---|---|
| DU (DTS unit) | The minimum unit of hardware resources (CPU + memory) required to run one DTS task. |
| Node | A single ECS instance in the cluster. Each node supports up to 15 DUs. |
| Cluster node specifications | Fixed at 15 DUs per node, supporting up to 15 concurrent DTS tasks on a non-overcommitted node. |
| Cluster node storage | Storage per node ranges from 1,024 GB to 30,720 GB. DTS caches data generated by tasks over the previous seven days and automatically clears data older than that. |
| Resource isolation | In a non-overcommitted cluster, hardware resources allocated to each DTS task are fully isolated. For example, a task using 4 DUs and a task using 10 DUs run on separate, non-competing resources. |
| Cluster overcommit ratio | The ratio at which cluster resources are overprovisioned, ranging from 100% to 200%. At 200%, each node provides 30 DUs instead of 15, allowing up to 30 concurrent tasks per node. Resource contention may occur when the overcommit ratio exceeds 100%, so use this mode only for workloads with low incremental data volumes or tasks that run in different time periods. |
Limitations
Network
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Dedicated clusters do not support the classic network.
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To access a database over the Internet or an Express Connect circuit, add the public and private CIDR blocks of the cluster's region to the database whitelist.
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For data synchronization tasks, the source database, destination database, and dedicated cluster must all be in the same region.
Capacity
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Each node supports only 15 DU specifications. With overcommitment mode at 200%, each node provides up to 30 DUs.
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Node count can range from 2 to 100. To avoid performance degradation, keep DU utilization below 50%.
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The number of nodes and the disk size of a dedicated cluster cannot be reduced after creation.
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A region can contain up to five dedicated clusters. To create more, contact Alibaba Cloud technical support to add your account to the whitelist.
Resource usage
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If CPU, memory, or disk usage exceeds 80%, scale up the cluster immediately. The Service Level Agreement does not cover task failures or switchover failures caused by insufficient resources.
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Make sure the total storage capacity of the cluster exceeds the total size of existing data in your DTS instances, and that available storage exceeds the total size of incremental data. Monitor storage usage with the Disk Usage metric on the Cluster Alert Management page. If the disk space cannot meet your business requirements, you can extend the disk capacity for the dedicated cluster.
Billing
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Dedicated clusters use only the subscription billing method. Payment is required at the time of purchase.
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Creating a DTS instance in a dedicated cluster does not incur additional charges.
Billing
For details on billable items and pricing rules, see Billing of DTS dedicated clusters.
Supported regions
DTS dedicated clusters are available in the following regions: China (Hangzhou), China (Shanghai), China (Beijing), China (Zhangjiakou), China (Shenzhen), China (Guangzhou), Japan (Tokyo), and US (Virginia).