Sentinel Pigeon Adapter

Sentinel Pigeon Adapter provides service invoker interceptor and provider interceptor for Pigeon services.

Note: This adapter only supports Pigeon 2.9.7 and above.

To use Sentinel Pigeon Adapter, you can simply add the following dependency to your pom.xml:

<dependency>
    <groupId>com.alibaba.csp</groupId>
    <artifactId>sentinel-pigeon-adapter</artifactId>
    <version>x.y.z</version>
</dependency>

The Sentinel filters are enabled by default. Once you add the dependency, the Pigeon services and methods will become protected resources in Sentinel, which can leverage Sentinel's flow control and guard ability when rules are configured. Demos can be found in sentinel-pigeon-demo.

For more details of Pigeon interceptor, see here.

Pigeon resources

The resource for Pigeon services has following granularity:

• Service method：resourceName format is interfaceName:methodSignature，e.g. com.alibaba.csp.sentinel.demo.pigeon.FooService:sayHello(java.lang.String)

Flow control based on caller

In many circumstances, it's also significant to control traffic flow based on the caller. For example, assuming that there are two services A and B, both of them initiate remote call requests to the service provider. If we want to limit the calls from service B only, we can set the limitApp of flow rule as the identifier of service B (e.g. service name).

Sentinel Pigeon Adapter will automatically resolve the Pigeon invoker's application name as the caller's name (origin), and will bring the caller's name when doing resource protection. If limitApp of flow rules is not configured (default), flow control will take effects on all callers. If limitApp of a flow rule is configured with a caller, then the corresponding flow rule will only take effect on the specific caller.

Global fallback

Sentinel Pigeon Adapter supports global fallback configuration. The global fallback will handle exceptions and give replacement result when blocked by flow control, degrade or system load protection. You can implement your own PigeonFallback interface and then register to PigeonFallbackRegistry. If no fallback is configured, Sentinel will wrap the BlockException then directly throw it out.