Resource Assurance is a service that guarantees resources to flexibly meet your business needs. It enables you to quantify the amount of available resources, reserve resources, plan private pools, and have a better experience when you query, reserve, purchase, and use resources.
|Quota management||Elastic Quota||Allows you to view quotas on resources such as instance types, images, disks, and security groups, and guarantees the provision of instance resources to some extent.|
||Allows you to reserve resources for different scenarios. After resources are reserved, the system generates private pools in which to retain the resources.|
|Private Pool||Private Pool||Provides guaranteed resources for you to create instances.|
|Elastic quota type||Description|
|Instance quota||Instance quotas are allocated based on zones, instance types, billing methods, and network types. Instance quotas are classified into the following types based on how well the provision of resources is guaranteed:
|Resource quota||Resource quotas are quotas on other ECS resources such as images, cloud disks, and security groups. You can apply to increase these quotas. For more information, see View and increase resource quotas.|
|Elasticity assurance||Provides guaranteed pay-as-you-go instance resources to meet irregular resource requirements.||Overview of Elasticity Assurance|
|Immediate capacity reservation||Provides guaranteed pay-as-you-go instance resources, and is typically used in conjunction with reserved instances or savings plans to meet large resource requirements.||Overview of Immediate Capacity Reservation|
|Item||Combination of elasticity assurances and pay-as-you-go instances||Combination of immediate capacity reservations, savings plans or regional reserved instances, and pay-as-you-go instances|
|Scenario||Some scenarios to which this solution is applicable:
The resource usage in the preceding scenarios demonstrates discrete peaks over time, as shown in the following figure.
|Some scenarios to which this solution is applicable:
The resource usage in the preceding scenarios is consistent over a specific period of time, as shown in the following figure.
|Flexibility in time||This solution allows for great flexibility in when resources are used. You do not need to plan when to use resources for an extended period of time but purchase resources when you need them.||This solution allows for limited flexibility in when resources are used. To make resources cost-effective, you need to plan when to use resources, and continuously use the resources over an extended period of time.|
|Resource reservation||Elasticity assurances provide resource reservations.||Immediate capacity reservations provide resource reservations.|
|Billing rule||Total price of resources reserved by an elasticity assurance = Assurance fee + Price of created pay-as-you-go instances
If you have purchased regional reserved instances or savings plans, you can apply them to the created pay-as-you-go instances.
|Total price of resources reserved by an immediate capacity reservation = Price of unused reserved capacity (billed at the pay-as-you-go instance rate) + Price of created pay-as-you-go instances.
Note During the validity period of an immediate capacity reservation, you are charged for the capacity reservation at the pay-as-you-go instance rate regardless of whether the reserved resources are used to create pay-as-you-go instances.
If you have purchased regional reserved instances or savings plans, you can apply them to the unused reserved capacity and the created pay-as-you-go instances.
All the resources that are automatically allocated by the system constitute a public pool. All users have access to the resources in the public pool. Instances may fail to be created due to insufficient resources in the public pool.
- When you reserve resources, you can select one of the following private pool types:
- Open: suited to common business that requires guaranteed resources.
- Targeted: suited to key business for which you want to reserve resources. To use a targeted private pool, you must specify the pool ID.
- When you use resources, you can use the Private Pool parameter to specify whether to use private pools and which type of private pools to use. Valid values for the Private Pool parameter:
- Open: The capacity in open private pools is given priority over public pool resources. If no capacity is available in private pools, the system attempts to use public pool resources.
- Targeted: A specified targeted or open private pool is used. If you set Private Pool to Targeted, you must specify the ID of a targeted or open private pool. If no capacity is available in the specified private pool, the instances cannot be created.
- None: The capacity in private pools is not used.
- Resources allocated based on business types
A system administrator creates multiple targeted private pools and informs O&M personnel and developers of different pool IDs. This ensures that different pools are used to create instances for O&M and development purposes.
- Resources allocated regardless of business types
A system administrator creates open private pools. The O&M personnel and developers first use the capacity in the open private pools to create instances. When no capacity is available in the private pools, resources in the public pool are used.
- Resources allocated exclusively to a specific business
A system administrator creates targeted private pools and configures instances to be created by using these pools for the specified business. When no capacity is available in the private pools, instances cannot be created.