This topic describes the terms of Elastic Compute Service (ECS) quotas. This topic also describes the adjustment policies and methods.

Terms

ECS instance quotas are classified into base quotas, reserved quotas, and total quotas. These types of quotas are based on the number of guaranteed available ECS resources.

  • Base quota: the minimum number of guaranteed available resources for an ECS instance.
  • Reserved quota: the amount of instance resources reserved by resource reservations. If you create instances within a reserved quota, you have guaranteed access to the resources that you request.
  • Total quota: the maximum number of guaranteed available resources for an ECS instance. A total quota includes a base quota, a reserved quota, and other quotas. Therefore, the total quota is greater than or equal to the base quota.

Quota adjustment policies

You can adjust quotas based on the usage of ECS instances. The following table describes the adjustment policies.
Item Adjustment policy Description
Base quota A base quota is automatically adjusted and allocated before the tenth day of each month based on the usage of your ECS resources. You cannot submit an application to increase the base quota. If you create ECS instances after the base quota is exceeded, the resources may become unavailable.
Reserved quota You can create the following resource reservations to increase reserved quotas: None.
Total quota

A total quota includes a base quota, a reserved quota, and other quotas. A total quota is automatically adjusted at the same time that the base quota is adjusted before the tenth day of each month. This ensures that the automatic increases of the total quota match the increases of your daily resource usage.

If you want extra ECS instances, you can submit an application to increase the total quota. After the total quota is increased to a specified value, the system keeps the total quota from falling below this value when the system automatically adjusts the total quota within at least 30 days.

If the number of your vCPUs or instances reaches the total quota, you cannot purchase new instances.

In addition, an instance quota can be classified into an instance type-specific quota and a zone-specific vCPU-based total quota for all instance types. You do not need to change the zone-specific vCPU-based total quota for all instance types. This value is always greater than the number of vCPUs that you require.

Total and used quotas

Both the total and used amounts of total quotas and base quotas are indicated as cumulative values over the last 15 days, including the current day. You do not need to apply for additional quotas. This applies if you create a large number of instances. Examples:

  • For example, you query a total quota on August 16. The displayed total quota is the total quota for August 2 to August 16. The displayed used quota is the number of running instances that are created from August 2 to August 16.
  • The base quota is not automatically adjusted, and you do not submit an application to increase the related total quota. In this case, the displayed total quota remains the same when you query the total quota on August 17. The displayed used quota is the number of running instances that are created from August 3 to August 17.
Note In some cases, a delay of up to 24 hours may occur when the system refreshes and displays used quotas. However, you can continue to create instances.

Methods to increase quotas

You can use one of the following methods to increase quotas: