a problem about "url" config in dubbo:reference

[maslke]

dubbo version: 2.7.3
os version: Windows 10
jdk version: 1.8

I met a problem when I learn to use the "url" config in dubbo:reference. I choose zookeeper as registry.

I have these codes in my provider.

interface GreetingService {
    String sayHello(String name);
}

class GreetingServiceImpl implements GreetingService {
    String sayHello(String name) {
        return "hello, " + name;
    }
}

I have these configs in my provider.xml

<bean id="target1" class="com.....GreetingServiceImpl" />
<bean id="target2" class="com.....GreetingServiceImpl" />

<dubbo:service interface="com....GreetingService" ref="target1" group="group1" version="2.0.0"/>
<dubbo:service interface="com...GreetingService" ref="target2" group="group2" version="2.0.0" />

Situation 1.
In this case, the consumer will work.

<dubbo:reference check="false" url="dubbo://127.0.0.1:20880?group=group1&amp;version=2.0.0"  id="mergerService" interface="com.maslke.dubbo.samples.merger.api.MergerService" group="group1" version="2.0.0" />

Situation 2.
In this case, the consumer will not work. It will throw an exception like this "Not found exported service".

<dubbo:reference check="false" url="dubbo://127.0.0.1:20880?group=group2&amp;version=2.0.0"  id="mergerService" interface="com.maslke.dubbo.samples.merger.api.MergerService" group="group2" version="2.0.0" />

Situation3.
I modify my provider.xml and add id to dubbo:service.

<bean id="target1" class="com.....GreetingServiceImpl" />
<bean id="target2" class="com.....GreetingServiceImpl" />

<dubbo:service id="greetingService" interface="com....GreetingService" ref="target1" group="group1" version="2.0.0"/>
<dubbo:service id="greetingServic2" interface="com...GreetingService" ref="target2" group="group2" version="2.0.0" />

If I do this，situation 1 and situation 2 will both work correctly.

So here is the question.

1. Is this a bug?
2. if this is not a bug, so id is necessary in my situation?

[imsunv]

@maslke I have checked this issue,

the reason is that when you did not set dubbo:service id, the service will use the default bean name as Path (interface name) with Increase id , so the one path is com....GreetingService, another is com....GreetingService2，the path does not equal with the consumer (com....GreetingService) so failed.

but when set dubbo:service id, will not use the bean name
the path set in the class ServiceBean#309

I'm not clearly sure that is a bug.

[maslke]

@maslke I have checked this issue,

the reason is that when you did not set dubbo:service id, the service will use the default bean name as Path (interface name) with Increase id , so the one path is com....GreetingService, another is com....GreetingService2，the path does not equal with the consumer (com....GreetingService) so failed.

but when set dubbo:service id, will not use the bean name
the path set in the class ServiceBean#309

I'm not clearly sure that is a bug.

thanks.perhaps always set id is the best practice.