org.apache.dubbo.registry.client

Class ServiceDiscoveryRegistry

java.lang.Object

org.apache.dubbo.registry.support.AbstractRegistry

org.apache.dubbo.registry.support.FailbackRegistry

org.apache.dubbo.registry.client.ServiceDiscoveryRegistry

All Implemented Interfaces:

Node, Registry, RegistryService

public class ServiceDiscoveryRegistry
extends FailbackRegistry

TODO, this bridge implementation is not necessary now, protocol can interact with service discovery directly. ServiceDiscoveryRegistry is a very special Registry implementation, which is used to bridge the old interface-level service discovery model with the new service discovery model introduced in 3.0 in a compatible manner.

It fully complies with the extension specification of the Registry SPI, but is different from the specific implementation of zookeeper and Nacos, because it does not interact with any real third-party registry, but only with the relevant components of ServiceDiscovery in the process. In short, it bridges the old interface model and the new service discovery model:

- register() aggregates interface level data into MetadataInfo by mainly interacting with MetadataService. - subscribe() triggers the whole subscribe process of the application level service discovery model. - Maps interface to applications depending on ServiceNameMapping. - Starts the new service discovery listener (InstanceListener) and makes NotifierListeners part of the InstanceListener.

Constructor Summary

Constructors

Constructor and Description
ServiceDiscoveryRegistry(URL registryURL, ApplicationModel applicationModel)

Method Summary

Modifier and Type	Method and Description
void	destroy()
void	doRegister(URL url)
void	doSubscribe(URL url, NotifyListener listener)
void	doUnregister(URL url)
void	doUnsubscribe(URL url, NotifyListener listener)
Lock	getAppSubscription(String key)
ServiceDiscovery	getServiceDiscovery()
Map<String,ServiceInstancesChangedListener>	getServiceListeners()
boolean	isAvailable()
boolean	isServiceDiscovery()
List<URL>	lookup(URL url) Query the registered data that matches the conditions.
void	register(URL url) Register data, such as : provider service, consumer address, route rule, override rule and other data.
void	removeAppSubscriptionLock(String key)
void	subscribe(URL url, NotifyListener listener) Subscribe to eligible registered data and automatically push when the registered data is changed.
static boolean	supports(URL registryURL) Supports or not ?
void	unregister(URL url) Unregister
void	unsubscribe(URL url, NotifyListener listener) Unsubscribe

Methods inherited from class org.apache.dubbo.registry.support.FailbackRegistry

reExportRegister, reExportUnregister, removeFailedRegisteredTask, removeFailedSubscribed, removeFailedSubscribedTask, removeFailedUnregisteredTask, removeFailedUnsubscribedTask

Methods inherited from class org.apache.dubbo.registry.support.AbstractRegistry

doSaveProperties, getCacheFile, getCacheProperties, getCacheUrls, getLastCacheChanged, getNotified, getRegistered, getSubscribed, getUrl, toString

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.dubbo.registry.Registry

getDelay

Constructor Detail

ServiceDiscoveryRegistry

public ServiceDiscoveryRegistry(URL registryURL,
                                ApplicationModel applicationModel)

Method Detail

getServiceDiscovery

public ServiceDiscovery getServiceDiscovery()

register

public final void register(URL url)

Description copied from interface: RegistryService

Register data, such as : provider service, consumer address, route rule, override rule and other data.

Registering is required to support the contract:
1. When the URL sets the check=false parameter. When the registration fails, the exception is not thrown and retried in the background. Otherwise, the exception will be thrown.
2. When URL sets the dynamic=false parameter, it needs to be stored persistently, otherwise, it should be deleted automatically when the registrant has an abnormal exit.
3. When the URL sets category=routers, it means classified storage, the default category is providers, and the data can be notified by the classified section.
4. When the registry is restarted, network jitter, data can not be lost, including automatically deleting data from the broken line.
5. Allow URLs which have the same URL but different parameters to coexist,they can't cover each other.

Specified by:

register in interface RegistryService

Overrides:

register in class FailbackRegistry

Parameters:

url - Registration information , is not allowed to be empty, e.g: dubbo://10.20.153.10/org.apache.dubbo.foo.BarService?version=1.0.0&application=kylin

doRegister

public void doRegister(URL url)

Specified by:

doRegister in class FailbackRegistry

unregister

public final void unregister(URL url)

Description copied from interface: RegistryService

Unregister

Unregistering is required to support the contract:
1. If it is the persistent stored data of dynamic=false, the registration data can not be found, then the IllegalStateException is thrown, otherwise it is ignored.
2. Unregister according to the full url match.

Specified by:

unregister in interface RegistryService

Overrides:

unregister in class FailbackRegistry

Parameters:

url - Registration information , is not allowed to be empty, e.g: dubbo://10.20.153.10/org.apache.dubbo.foo.BarService?version=1.0.0&application=kylin

doUnregister

public void doUnregister(URL url)

Specified by:

doUnregister in class FailbackRegistry

subscribe

public final void subscribe(URL url,
                            NotifyListener listener)

Description copied from interface: RegistryService

Subscribe to eligible registered data and automatically push when the registered data is changed.

Subscribing need to support contracts:
1. When the URL sets the check=false parameter. When the registration fails, the exception is not thrown and retried in the background.
2. When URL sets category=routers, it only notifies the specified classification data. Multiple classifications are separated by commas, and allows asterisk to match, which indicates that all categorical data are subscribed.
3. Allow interface, group, version, and classifier as a conditional query, e.g.: interface=org.apache.dubbo.foo.BarService&version=1.0.0
4. And the query conditions allow the asterisk to be matched, subscribe to all versions of all the packets of all interfaces, e.g. :interface=*&group=*&version=*&classifier=*
5. When the registry is restarted and network jitter, it is necessary to automatically restore the subscription request.
6. Allow URLs which have the same URL but different parameters to coexist,they can't cover each other.
7. The subscription process must be blocked, when the first notice is finished and then returned.

Specified by:

subscribe in interface RegistryService

Overrides:

subscribe in class FailbackRegistry

Parameters:

url - Subscription condition, not allowed to be empty, e.g. consumer://10.20.153.10/org.apache.dubbo.foo.BarService?version=1.0.0&application=kylin

listener - A listener of the change event, not allowed to be empty

doSubscribe

public void doSubscribe(URL url,
                        NotifyListener listener)

Specified by:

doSubscribe in class FailbackRegistry

unsubscribe

public final void unsubscribe(URL url,
                              NotifyListener listener)

Description copied from interface: RegistryService

Unsubscribe

Unsubscribing is required to support the contract:
1. If you don't subscribe, ignore it directly.
2. Unsubscribe by full URL match.

Specified by:

unsubscribe in interface RegistryService

Overrides:

unsubscribe in class FailbackRegistry

Parameters:

url - Subscription condition, not allowed to be empty, e.g. consumer://10.20.153.10/org.apache.dubbo.foo.BarService?version=1.0.0&application=kylin

listener - A listener of the change event, not allowed to be empty

doUnsubscribe

public void doUnsubscribe(URL url,
                          NotifyListener listener)

Specified by:

doUnsubscribe in class FailbackRegistry

lookup

public List<URL> lookup(URL url)

Description copied from interface: RegistryService

Query the registered data that matches the conditions. Corresponding to the push mode of the subscription, this is the pull mode and returns only one result.

Specified by:

lookup in interface RegistryService

Overrides:

lookup in class AbstractRegistry

Parameters:

url - Query condition, is not allowed to be empty, e.g. consumer://10.20.153.10/org.apache.dubbo.foo.BarService?version=1.0.0&application=kylin

Returns:

The registered information list, which may be empty, the meaning is the same as the parameters of org.apache.dubbo.registry.NotifyListener#notify(List).

See Also:

NotifyListener.notify(List)

isAvailable

public boolean isAvailable()

destroy

public void destroy()

Specified by:

destroy in interface Node

Overrides:

destroy in class FailbackRegistry

isServiceDiscovery

public boolean isServiceDiscovery()

supports

public static boolean supports(URL registryURL)

Supports or not ?

Parameters:

registryURL - the url of registry

Returns:

if supported, return true, or false

getServiceListeners

public Map<String,ServiceInstancesChangedListener> getServiceListeners()

getAppSubscription

public Lock getAppSubscription(String key)

removeAppSubscriptionLock

public void removeAppSubscriptionLock(String key)