A deployment set is a strategy that controls the distribution of instances and enables you to design the capacity and availability of disaster tolerance as you create an instance.

Deployment strategy

You can use a deployment set to distribute ECS instances involved in your business across different physical servers to guarantee high availability and capacity, and establish low-level disaster tolerance. When you create a deployment set for instance distribution, Alibaba Cloud starts the instances separately in the specified regions based on the deployment strategy that you set up. If you have not created a specific deployment set for your instances, the instances are started on different physical servers to ensure the availability of services as much as possible.

Currently, deployment sets support the high availability strategy:

  • When you use the high availability strategy, all ECS instances within the deployment set are strictly distributed across different physical servers in the specified region. The high availability strategy applies to application architectures where several ECS instances need to be isolated from each other. The strategy significantly reduces the chances of service being unavailable.

  • Note that by using the high availability strategy, you may not be able to create an ECS instance when you encounter a supply shortage in the region. Furthermore, a Pay-As-You-Go instance with no termination fees can cause a restart failure. If this occurs, you need to wait a while and then create or restart an instance again.

Deployment example

The following figure is a typical example of how to improve business reliability with a deployment set. Here, four ECS instances are distributed on four different physical servers.

If you want to achieve low latency communication between the instances of the deployment set, we recommend that you make sure the network types of the instances are the same. For example, when creating instances, select the same VPC for those instances.

Billing details

No service fees are charged when you use the deployment set. However, fees are incurred through usage of the instances, disks, images, and bandwidth. For more information, see Pricing overview.

Limits

Before you use the deployment set, note that:

  • Merging deployment sets is not supported.

  • Preemptable instances cannot be created in a deployment set.

  • Dedicated hosts cannot be created in a deployment set.

  • When you create an instance in a deployment set, you can create a maximum of seven ECS instances per zone.

  • The instance type families that can be created in the deployment set includes c5, d1, d1ne, g5, hfc5, hfg5, i2, ic5, r5, se1ne, sn1ne, and sn2ne. For more information about instance types and their performance, see Instance type families.

  • You may not be able to create an instance or restart a Pay-As-You-Go instance with no termination fees in the deployment set due to a supply shortage.

Related operations

Console operations

API operations