Breaking change in NameResolverProvider with latest release

[ST-DDT]

What version of gRPC are you using?

1.19.0

What did you expect to see?

I use yidongnan/grpc-spring-boot-starter 2.3.0 and use custom NameResolvers to connect remote services. Due to interoperability conflicts with java's service loaders I cannot directly access/use the provided grpc NameResolvers and have to first use spring logic to determine the remote host before using the NameResolvers.
Due to the changes introduced in grpc-java 1.19 (method parameter change) I am now unable to
use the 1.18 API with NameResolverProviders.

The change in https://github.com/grpc/grpc-java/pull/5345/files#diff-0b140e8a0a77a6eda416c5a42033462b simply exchanged the parameters without providing a method for backwards compatibility.

Due to this change I'm unable to provide support for either <=1.18 or >=1.19 versions.
I know that at some point the other method will be removed, but I hope to have some time for migration.

ConfigMappedNameResolverFactory (springNameResolver)

    @Nullable
    @Override
    public NameResolver newNameResolver(final URI targetUri, final Attributes params) {
        final String clientName = targetUri.toString();
        final GrpcChannelProperties clientConfig = this.config.getChannel(clientName);
        URI remappedUri = clientConfig.getAddress();
        if (remappedUri == null) {
            remappedUri = this.defaultUriMapper.apply(clientName);
            if (remappedUri == null) {
                throw new IllegalStateException("No targetUri provided for '" + clientName + "'"
                        + " and defaultUri mapper returned null.");
            }
        }
        log.debug("Remapping target URI for {} to {} via {}", clientName, remappedUri, this.delegate);
        final Attributes extendedParas = params.toBuilder()
                .set(NameResolverConstants.PARAMS_CLIENT_NAME, clientName)
                .set(NameResolverConstants.PARAMS_CLIENT_CONFIG, clientConfig)
                .build();
        return this.delegate.newNameResolver(remappedUri, extendedParas);
    }

Caused by: java.lang.UnsupportedOperationException: This method is going to be deleted
    at io.grpc.NameResolver$Factory.newNameResolver (NameResolver.java:135)
    at net.devh.boot.grpc.client.nameresolver.ConfigMappedNameResolverFactory.newNameResolver (ConfigMappedNameResolverFactory.java:85)
    at io.grpc.NameResolver$Factory.newNameResolver (NameResolver.java:151)
    at io.grpc.internal.ManagedChannelImpl.getNameResolver (ManagedChannelImpl.java:646)
    at io.grpc.internal.ManagedChannelImpl.<init> (ManagedChannelImpl.java:561)
    at io.grpc.internal.AbstractManagedChannelImplBuilder.build (AbstractManagedChannelImplBuilder.java:449)
    at net.devh.boot.grpc.client.channelfactory.AbstractChannelFactory.newManagedChannel (AbstractChannelFactory.java:132)
    at java.util.concurrent.ConcurrentHashMap.computeIfAbsent (ConcurrentHashMap.java:1705)
    at net.devh.boot.grpc.client.channelfactory.AbstractChannelFactory.createChannel (AbstractChannelFactory.java:98)
    at net.devh.boot.grpc.client.inject.GrpcClientBeanPostProcessor.processInjectionPoint (GrpcClientBeanPostProcessor.java:110)
    at net.devh.boot.grpc.client.inject.GrpcClientBeanPostProcessor.postProcessBeforeInitialization (GrpcClientBeanPostProcessor.java:77)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsBeforeInitialization (AbstractAutowireCapableBeanFactory.java:414)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean (AbstractAutowireCapableBeanFactory.java:1770)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean (AbstractAutowireCapableBeanFactory.java:593)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean (AbstractAutowireCapableBeanFactory.java:515)
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0 (AbstractBeanFactory.java:320)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton (DefaultSingletonBeanRegistry.java:222)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean (AbstractBeanFactory.java:318)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean (AbstractBeanFactory.java:199)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons (DefaultListableBeanFactory.java:849)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization (AbstractApplicationContext.java:877)
    at org.springframework.context.support.AbstractApplicationContext.refresh (AbstractApplicationContext.java:549)
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh (ServletWebServerApplicationContext.java:142)
    at org.springframework.boot.SpringApplication.refresh (SpringApplication.java:775)
    at org.springframework.boot.SpringApplication.refreshContext (SpringApplication.java:397)
    at org.springframework.boot.SpringApplication.run (SpringApplication.java:316)
    at com.example.Main.main (Main.java:38)
    at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
    at jdk.internal.reflect.NativeMethodAccessorImpl.invoke (NativeMethodAccessorImpl.java:62)
    at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke (Method.java:566)
    at org.springframework.boot.maven.AbstractRunMojo$LaunchRunner.run (AbstractRunMojo.java:558)
    at java.lang.Thread.run (Thread.java:834)

Did you forget to add the method override or is it intentional?

TLDR

Temporarily re-add
io.grpc.NameResolverProvider.NameResolverFactory#newNameResolver(URI targetUri, Attributes params) and delegate it to the other method.

Related

• Tracking NameResolverProvider being experimental #4159
• core: introduce NameResolver.Helper and deprecate the params on newNameResolver() #5345
• https://github.com/yidongnan/grpc-spring-boot-starter/issues/203

[zhangkun83]

We took care of the migration of the implementors of NameResolver, but didn't consider callers, because we thought only gRPC would be the caller. Seems I made the wrong assumption. I can add the implementation to the old method in the upcoming 1.20.0

[ST-DDT]

Thanks for your help.

[zhangkun83]

@ST-DDT I noticed that you are putting custom attributes. After switching away from the Attraibutes params, you will no longer be able to do it. Can you file a feature request issue to tell us about your use case, so that we can add the support for it in the new Helper-based API?

[ST-DDT]

@ST-DDT I noticed that you are putting custom attributes. After switching away from the Attraibutes params, you will no longer be able to do it. Can you file a feature request issue to tell us about your use case, so that we can add the support for it in the new Helper-based API?

Done in #5562