By default, each node in a Data Transmission Service (DTS) dedicated cluster runs up to 15 tasks. If your tasks have low resource usage—for example, they process small volumes of incremental data or run at different times—you can set an overcommit ratio to fit more tasks on the same hardware and reduce costs.
How overcommitment works
A DTS unit (DU) is the resource unit of a DTS dedicated cluster. One DU represents the minimum hardware resources required to run one DTS task (data migration, data synchronization, or change tracking).
By default, each node provides 15 DUs, so you can run up to 15 tasks per node. Setting an overcommit ratio above 100% increases the virtual DU count without adding physical resources. For example, a 200% ratio doubles the DU count to 30, allowing up to 30 concurrent tasks per node—but each task receives half the resources it would at the default setting.
The following table shows the effect of different overcommit ratios on a single node:
| Overcommit ratio | DUs per node | Max tasks per node |
|---|---|---|
| 100% (default) | 15 | 15 |
| 200% | 30 | 30 |
Higher overcommit ratios reduce the average CPU, memory, and disk space available to each task. This can degrade task performance and stability. Increase the ratio only when tasks are unlikely to compete for resources simultaneously.
Prerequisites
Before you begin, ensure that you have:
A DTS dedicated cluster (Create a DTS dedicated cluster)
Set the overcommit ratio
Go to the Dedicated Cluster page.
In the top navigation bar, select the region where your cluster is located.
On the Cluster Task page, open the Set Cluster Overcommit Ratio panel using one of the following methods:
Find your cluster. In the Actions column, click the
icon and select Set Cluster Overcommit Ratio.Find your cluster. In the Actions column, click Details. On the Cluster Management page, click Set Cluster Overcommit Ratio.
In the Set Cluster Overcommit Ratio section, set the Overcommit Ratio parameter to a value between 100% and 200%. Choose a ratio based on your workload:
Use a lower ratio (100%–150%) if tasks have variable resource demands or run simultaneously.
Use a higher ratio (up to 200%) if tasks process small volumes of incremental data or run at different times with minimal overlap.
In the Service Agreement section, read the Terms of Service and select the check box to agree.
Click OK.