Configure fallback behaviors

Prerequisites

Before you begin, make sure you have:

• MSE Enterprise Edition activated

• Microservices Governance enabled for your applications. For setup instructions, see:

  • Enable Microservices Governance for Java microservice applications in an ACK or ACS cluster

  • Enable Microservices Governance for microservice applications on ECS instances

Create a behavior

1. Log on to the MSE console, and select a region in the top navigation bar.

2. In the left-side navigation pane, choose Microservices Governance > Application Governance.

3. On the Application list page, click the resource card of the desired application. In the left-side navigation pane, click Traffic management.

4. On the Traffic management page, click the Flow protection tab, and then click the Behavior Management tab.

5. Click New behavior. In the New behavior dialog box, select a resource type, complete the configuration, and then click New.

   Web resource

   Parameter	Description	Example
   Behavior Name	A unique name for the behavior within the application, up to 128 characters long.	Test behavior
   Resource Type	Select Web.	Web
   Web Throttling Policy	Specifies the action to take when a rule is triggered for a Web interface. If you select Custom return, you must specify the HTTP status code, content format, and response body to return custom content.	Custom return
   HTTP Status Code	The default value is 429. This parameter is required when Web Throttling Policy is set to Custom return.	429
   Returned Content-Type	The format of the response body. You can select Plain text or JSON.	JSON
   Returned HTTP Text	The content of the response body returned when the rule is triggered. This parameter is required when Web Throttling Policy is set to Custom return.	{"message": "blocked oops"}

   RPC resource

   Parameter	Description	Example
   Behavior Name	A unique name for the behavior within the application, up to 128 characters long.	Test behavior
   Resource Type	Select RPC. Note Apache Dubbo 2.7.0 to 2.7.3 does not support custom behaviors. In these versions, throttling returns a java.lang.RuntimeException that includes SentinelBlockedException and throttling details.	RPC
   Rpc current limiting processing strategy	Specifies the action to take when a rule is triggered for an RPC interface. Custom return: Returns a custom result. You must configure the response class and content. Custom exception: Throws a custom exception. You must configure the exception class name and message.	Custom return/Custom exception
   Rpc current limiting processing strategy is set to Custom return
   Custom Response Class Name	Enter the fully qualified class name. Note Custom return does not currently support object types with unresolved generic parameters, such as Map<K, V> and List<T>.	com.alibaba.demo.OrderService:getOrder(long)
   Custom Response Content (JSON Format)	The content of the object to return when the rule is triggered for the RPC interface.	{"id": "123", "name": "test"}
   Rpc current limiting processing strategy is set to Custom exception
   Exception Class Name	Enter the fully qualified exception class name.	java.lang.RuntimeException
   Exception Message Text	Enter the message for the custom exception that is thrown when a rule is triggered for the RPC interface.	"Operation failed"

   The new behavior appears on the Behavior Management page.

Modify or delete a behavior

1. Log on to the MSE console, and select a region in the top navigation bar.

2. In the left-side navigation pane, choose Microservices Governance > Application Governance.

3. On the Application list page, click the resource card of the desired application. In the left-side navigation pane, click Traffic management.

4. On the Traffic management page, click the Flow protection tab, and then click the Behavior Management tab.

5. Find the target behavior and click Revised or Delete in the Actions column.

Associate a behavior with a rule

You can associate different fallback behaviors with different control rules. This section uses a throttling rule as an example.

1. Log on to the MSE console, and select a region in the top navigation bar.

2. In the left-side navigation pane, choose Microservices Governance > Application Governance.

3. On the Application list page, click the resource card of the desired application. In the left-side navigation pane, click Traffic management.

4. On the Traffic management page, click the Flow protection tab, and then click the Interface Flow Control tab.

5. On the Interface Flow Control tab, click Add Throttling Rule.

6. In the Add Throttling Protection Rule dialog box, complete the configuration. After you complete the Select Protection Scenario and Configure Protection Rule steps, configure the following parameters in the Configure Protection Behavior area.

   1. In the Select Protection Scenario step, select API Type as WEB service or RPC service, and then select Type of traffic, Interface Name, and Protection Type.

   2. In the Configure Protection Rule step, set the Stand-alone QPS threshold and select a Flow control effect.

   3. In the Configure Protection Behavior step, select a target behavior from the Association Behavior drop-down list, or click New behavior to create a new one.

   Note

   • To use the default fallback behavior for throttling, do not specify an API type.

   • Associating a behavior with a rule overwrites any previously associated behavior.

   • If you do not select an API type, the default behavior is used. After you associate a behavior of a specific API type, you can modify the behavior, but you cannot change its type.

   • Custom behaviors configured in Microservices Governance do not affect the Feign framework, as its native fallback mechanism takes precedence.

7. Click New.