Tags are used to identify cloud resources. They allow you to categorize, search for, and aggregate cloud resources that share the same characteristics across different dimensions. This facilitates more efficient resource management.
Scenarios
Search for resources
You can add tags to resources and search for resources based on tags in the Resource Management console or by calling a tag-related API operation. For more information, see Search for resources by tag.
Implement automated O&M
You can add different tags to resources in different environments, resources that run different operating systems, or resources on different mobile platforms. The environments include the production environment and test environment. The operating systems include Windows and Linux. The mobile platforms include iOS and Android. Then, you can create templates in CloudOps Orchestration Service (OOS) and execute the templates to perform batch automated O&M operations. For more information, see Overview of automated O&M by tag.
Control access to resources
You can use tags in Resource Access Management (RAM) to manage the access and operation permissions of RAM users on different cloud resources. For more information, see Use tags to control access to ECS resources.
Benefits
Convenience: A unified, visualized console is provided to manage the resources to which tags are added.
Flexibility: You can add, remove, modify, or query one or more tags in the console or by calling an API operation.
Visibility: You can use tags to manage separate bills for departments, products, and projects.
Terms
Term | Description |
key-value pair | A tag consists of a key-value pair. |
Preset tag | A preset tag is a tag that you create in advance and that applies to all regions. Preset tags can exist without being attached to resources. They are not automatically deleted if they are not attached to any resources. Preset tags are suitable for use in the tag planning stage. You can create preset tags in the stage of tag planning and add them to specific cloud resources in the stage of tag implementation. For more information, see Create a tag. |
System tag | A system tag is defined by the system. You can only query system tags. System tags present data relationships in a standard manner. In some specific cases, you can use system tags to assist in processing your business. For example, a cluster is associated with an Elastic Compute Service (ECS) instance, and the system adds the system tag of the cluster ID to the ECS instance. This way, you can determine the attribution of the ECS instance based on the system tag. For more information, see View system tags and resources to which the tags are added. |
createdby tag | createdby tag is a type of system tag that is provided by Alibaba Cloud and automatically added to resources. This type of tag is used to identify the creators of resources. createdby tags can help you analyze costs and bills and manage the costs of cloud resources in an efficient manner. For more information, see Overview of createdby tags. |
Tag policy | Tag policies are a type of policy that is used to standardize the tags that are added to resources. You can use a tag policy to define the tags that must be added to your resources. Compliant tags can help you improve efficiency in aspects such as tag-based cost allocation, tag-based access control, and automated O&M. Tag policies support the single-account mode and multi-account mode. The two modes can meet your business requirements for standardized tag management in different stages. For more information, see Overview of tag policies. |
Alibaba Cloud services that support tags
A variety of core Alibaba Cloud services support tags, including ECS, ApsaraDB RDS, Object Storage Service (OSS), Virtual Private Cloud (VPC), Server Load Balancer (SLB), and Container Service for Kubernetes (ACK). Alibaba Cloud plans to extend tag support to additional services. For more information, see Alibaba Cloud services that support tags.
Limits
Limit | Specification | How to increase the quota | Note |
Maximum number of tags that can be added to a single resource | 20 |
| |
Maximum number of preset tags that can be created within a single Alibaba Cloud account | 1,000 | None | None |
Maximum number of tag values that can be specified for a single preset tag key | 1,000 | None | None |
Limit on tag keys | A tag key can contain a maximum of 128 characters. It cannot start with | None | None |
Tag value | A tag value can contain a maximum of 128 characters. It cannot start with | None | None |
Adding tags to resources | Each tag key on a resource can have only one tag value. If you attempt to add a tag that has the same key as an existing tag, the value of the existing tag is overwritten. For example, if a resource has the | None | None |