ServiceProvider Requires Curator Client Start

[dclements]

Creating a service provider requires that a ZK client has already been started and thus throws an exception while the injector is being constructed. In the absence of this it will figure it out later on a retry, but there needs to be a way to effectively delay the ServiceProvider startup.

[dclements]

Stack trace:

java.lang.IllegalStateException: Client is not started
    at com.google.common.base.Preconditions.checkState(Preconditions.java:176)
    at org.apache.curator.CuratorZookeeperClient.getZooKeeper(CuratorZookeeperClient.java:113)
    at org.apache.curator.utils.EnsurePath$InitialHelper$1.call(EnsurePath.java:148)
    at org.apache.curator.RetryLoop.callWithRetry(RetryLoop.java:107)
    at org.apache.curator.utils.EnsurePath$InitialHelper.ensure(EnsurePath.java:141)
    at org.apache.curator.utils.EnsurePath.ensure(EnsurePath.java:99)
    at org.apache.curator.framework.imps.NamespaceImpl.fixForNamespace(NamespaceImpl.java:74)
    at org.apache.curator.framework.imps.NamespaceImpl.newNamespaceAwareEnsurePath(NamespaceImpl.java:87)
    at org.apache.curator.framework.imps.CuratorFrameworkImpl.newNamespaceAwareEnsurePath(CuratorFrameworkImpl.java:437)
    at org.apache.curator.framework.recipes.cache.PathChildrenCache.<init>(PathChildrenCache.java:221)
    at org.apache.curator.framework.recipes.cache.PathChildrenCache.<init>(PathChildrenCache.java:180)
    at org.apache.curator.x.discovery.details.ServiceCacheImpl.<init>(ServiceCacheImpl.java:65)
    at org.apache.curator.x.discovery.details.ServiceCacheBuilderImpl.build(ServiceCacheBuilderImpl.java:47)
    at org.apache.curator.x.discovery.details.ServiceProviderImpl.<init>(ServiceProviderImpl.java:52)
    at org.apache.curator.x.discovery.details.ServiceProviderBuilderImpl.build(ServiceProviderBuilderImpl.java:45)
    at com.readytalk.cultivar.discovery.ServiceProviderProvider.get(ServiceProviderProvider.java:62)
    at com.readytalk.cultivar.discovery.ServiceProviderProvider.get(ServiceProviderProvider.java:22)
    at com.google.inject.internal.BoundProviderFactory.get(BoundProviderFactory.java:55)
    at com.google.inject.internal.ProviderToInternalFactoryAdapter$1.call(ProviderToInternalFactoryAdapter.java:46)
    at com.google.inject.internal.InjectorImpl.callInContext(InjectorImpl.java:1031)
    at com.google.inject.internal.ProviderToInternalFactoryAdapter.get(ProviderToInternalFactoryAdapter.java:40)
    at com.google.inject.Scopes$1$1.get(Scopes.java:65)
    at com.google.inject.internal.InternalFactoryToProviderAdapter.get(InternalFactoryToProviderAdapter.java:40)
    at com.google.inject.internal.FactoryProxy.get(FactoryProxy.java:54)
    at com.google.inject.internal.ProviderToInternalFactoryAdapter$1.call(ProviderToInternalFactoryAdapter.java:46)
    at com.google.inject.internal.InjectorImpl.callInContext(InjectorImpl.java:1031)
    at com.google.inject.internal.ProviderToInternalFactoryAdapter.get(ProviderToInternalFactoryAdapter.java:40)
    at com.google.inject.Scopes$1$1.get(Scopes.java:65)
    at com.google.inject.internal.InternalFactoryToProviderAdapter.get(InternalFactoryToProviderAdapter.java:40)
    at com.google.inject.internal.SingleParameterInjector.inject(SingleParameterInjector.java:38)
    at com.google.inject.internal.SingleParameterInjector.getAll(SingleParameterInjector.java:62)
    at com.google.inject.internal.ConstructorInjector.construct(ConstructorInjector.java:84)
    at com.google.inject.internal.ConstructorBindingImpl$Factory.get(ConstructorBindingImpl.java:254)
    at com.google.inject.internal.FactoryProxy.get(FactoryProxy.java:54)
    at com.google.inject.internal.ProviderToInternalFactoryAdapter$1.call(ProviderToInternalFactoryAdapter.java:46)
    at com.google.inject.internal.InjectorImpl.callInContext(InjectorImpl.java:1031)
    at com.google.inject.internal.ProviderToInternalFactoryAdapter.get(ProviderToInternalFactoryAdapter.java:40)
    at com.google.inject.Scopes$1$1.get(Scopes.java:65)
    at com.google.inject.internal.InternalFactoryToProviderAdapter.get(InternalFactoryToProviderAdapter.java:40)
    at com.google.inject.internal.ExposedKeyFactory.get(ExposedKeyFactory.java:54)
    at com.google.inject.internal.FactoryProxy.get(FactoryProxy.java:54)
    at com.google.inject.internal.InjectorImpl$4$1.call(InjectorImpl.java:978)
    at com.google.inject.internal.InjectorImpl.callInContext(InjectorImpl.java:1031)
    at com.google.inject.internal.InjectorImpl$4.get(InjectorImpl.java:974)
    at com.google.inject.multibindings.Multibinder$RealMultibinder.get(Multibinder.java:326)
    at com.google.inject.multibindings.Multibinder$RealMultibinder.get(Multibinder.java:220)
    at com.google.inject.internal.InternalFactoryToProviderAdapter.get(InternalFactoryToProviderAdapter.java:40)
    at com.google.inject.internal.InjectorImpl$4$1.call(InjectorImpl.java:978)
    at com.google.inject.internal.InjectorImpl.callInContext(InjectorImpl.java:1031)
    at com.google.inject.internal.InjectorImpl$4.get(InjectorImpl.java:974)
    at com.google.inject.spi.ProviderLookup$1.get(ProviderLookup.java:89)
    at com.google.inject.internal.ProviderMethod.get(ProviderMethod.java:98)
    at com.google.inject.internal.InternalFactoryToProviderAdapter.get(InternalFactoryToProviderAdapter.java:40)
    at com.google.inject.internal.ProviderToInternalFactoryAdapter$1.call(ProviderToInternalFactoryAdapter.java:46)
    at com.google.inject.internal.InjectorImpl.callInContext(InjectorImpl.java:1031)
    at com.google.inject.internal.ProviderToInternalFactoryAdapter.get(ProviderToInternalFactoryAdapter.java:40)
    at com.google.inject.Scopes$1$1.get(Scopes.java:65)
    at com.google.inject.internal.InternalFactoryToProviderAdapter.get(InternalFactoryToProviderAdapter.java:40)
    at com.google.inject.internal.SingleParameterInjector.inject(SingleParameterInjector.java:38)
    at com.google.inject.internal.SingleParameterInjector.getAll(SingleParameterInjector.java:62)
    at com.google.inject.internal.ConstructorInjector.construct(ConstructorInjector.java:84)
    at com.google.inject.internal.ConstructorBindingImpl$Factory.get(ConstructorBindingImpl.java:254)
    at com.google.inject.internal.FactoryProxy.get(FactoryProxy.java:54)
    at com.google.inject.internal.ProviderToInternalFactoryAdapter$1.call(ProviderToInternalFactoryAdapter.java:46)
    at com.google.inject.internal.InjectorImpl.callInContext(InjectorImpl.java:1031)
    at com.google.inject.internal.ProviderToInternalFactoryAdapter.get(ProviderToInternalFactoryAdapter.java:40)
    at com.google.inject.Scopes$1$1.get(Scopes.java:65)
    at com.google.inject.internal.InternalFactoryToProviderAdapter.get(InternalFactoryToProviderAdapter.java:40)
    at com.google.inject.internal.InternalInjectorCreator$1.call(InternalInjectorCreator.java:204)
    at com.google.inject.internal.InternalInjectorCreator$1.call(InternalInjectorCreator.java:198)
    at com.google.inject.internal.InjectorImpl.callInContext(InjectorImpl.java:1024)
    at com.google.inject.internal.InternalInjectorCreator.loadEagerSingletons(InternalInjectorCreator.java:198)
    at com.google.inject.internal.InternalInjectorCreator.injectDynamically(InternalInjectorCreator.java:179)
    at com.google.inject.internal.InternalInjectorCreator.build(InternalInjectorCreator.java:109)
    at com.google.inject.Guice.createInjector(Guice.java:95)
    at com.google.inject.Guice.createInjector(Guice.java:83)
    at x.y.z.DiscoveryModuleTest$DiscoveryIntegTest.setUp(DiscoveryModuleTest.java:151)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:45)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:42)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:27)
    at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:30)
    at org.junit.rules.ExternalResource$1.evaluate(ExternalResource.java:46)
    at org.junit.internal.runners.statements.FailOnTimeout$StatementThread.run(FailOnTimeout.java:62)

The problem is as follows:

• A new ServiceProviderImpl is created by the ServiceProviderProvider.
• The ServiceProviderImpl, inside of the constructor, creates a ServiceCache using discovery.serviceCacheBuilder().name(serviceName).threadFactory(threadFactory).build();
• This creates a new PathChildrenCache after generating a pathForName for the name.
• This then calls newNamespaceAwareEnsurePath on the CuratorFramework, which is where our problem begins.
• Deep within EnsurePath.ensure there is a state check that sees that the CuratorFramework has not been started yet.

This means that this only happens when there is a namespace, creating inconsistent behavior between the namespace and non-namespace versions.

This does not appear to be causing ill effects at this time since it will continue to use the EnsurePath.ensure, so the biggest ramification appears to be that an errant message appears in the log.