API Gateway 10.15 | Using API Gateway | Implement APIs | Policies | Transport | Enable Bulkhead | Enabling bulkhead for APIs at the API level
 
Enabling bulkhead for APIs at the API level
This use case explains how to configure the bulkhead limit for an API.
This use case starts when you have an API for which you have to enforce a bulkhead limit and ends when you have successfully applied the bulkhead limit to the API.
*To enforce bulkhead limit to an API
1. Click APIs in the title navigation bar.
2. Select the required API.
3. Click the Policies tab.
4. From the Policy catalog section, expand Transport, and select Enable bulkhead.
5. Provide the following values in the Policy properties section:
Field
Description
Maximum concurrent calls
Specify the maximum number of concurrent requests that the API can process, exceeding which the requests are rejected.
Enable bulkhead for callbacks
Select this option to specify the maximum number of concurrent callbacks for the API. If you select this the Maximum concurrent callbacks field appears.
Note:
This setting is applicable only for REST APIs. Hence, this field is not displayed when you perform the bulkhead limit configuration for any other APIs.
Maximum concurrent callbacks
Specify the maximum number of concurrent callbacks that the API can process, exceeding which the callbacks are rejected. This field appears only when you have selected the Enable bulkhead for callbacks check box.
Add Retry-After response header
Select this option to include the Retry-after header in the response sent to the client when requests are rejected. This is to keep the client informed about the waiting duration before sending any consecutive requests.
Note:
This option is to provide an approximate waiting duration before sending any consecutive requests; and it does not guarantee that the requests sent after the specified time are processed. The maximum number of concurrent requests that are processed is purely dependant on the configured bulkhead limit.
Retry after (value, in seconds)
Specify the duration that the client must wait, after requests are rejected by API Gateway, to send consecutive requests. This field appears only when you have selected the Retry after (value, in seconds) check box.
6. Click Save.
The bulkhead limit is applied to the API.