MeterRegistryPostProcessor dependency on ApplicationContext causes early context initialization

[ilx]

With recent spring-boot-actuator-autoconfigure-3.2.4.jar BeanPostProcessorChecker produces warnings when we apply MetricsAutoConfiguration:

2024-04-25 17:59:57.980 [main] {} WARN  org.springframework.context.support.PostProcessorRegistrationDelegate$BeanPostProcessorChecker - Bean 'distributedFeaturesConfiguration' of type [com.xebialabs.xlrelease.features.distributed.DistributedFeaturesConfiguration$$SpringCGLIB$$0] is not eligible for getting processed by all BeanPostProcessors (for example: not eligible for auto-proxying). Is this bean getting eagerly injected into a currently created BeanPostProcessor [meterRegistryPostProcessor]? Check the corresponding BeanPostProcessor declaration and its dependencies.

The stacktrace of the 1st time it ends up in org.springframework.context.support.PostProcessorRegistrationDelegate.BeanPostProcessorChecker#postProcessAfterInitialization is:

Breakpoint reached
	at org.springframework.context.support.PostProcessorRegistrationDelegate$BeanPostProcessorChecker.postProcessAfterInitialization(PostProcessorRegistrationDelegate.java:437)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsAfterInitialization(AbstractAutowireCapableBeanFactory.java:438)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1789)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:600)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:522)
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:326)
	at org.springframework.beans.factory.support.AbstractBeanFactory$$Lambda$766/0x00000008015fe6f0.getObject(Unknown Source:-1)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:324)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200)
	at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:409)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1335)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1165)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:562)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:522)
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:326)
	at org.springframework.beans.factory.support.AbstractBeanFactory$$Lambda$766/0x00000008015fe6f0.getObject(Unknown Source:-1)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:324)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200)
	at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:254)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1443)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1353)
	at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:904)
	at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:782)
	at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:237)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1355)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1192)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:562)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:522)
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:326)
	at org.springframework.beans.factory.support.AbstractBeanFactory$$Lambda$766/0x00000008015fe6f0.getObject(Unknown Source:-1)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:324)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200)
	at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:409)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1335)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1165)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:562)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:522)
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:326)
	at org.springframework.beans.factory.support.AbstractBeanFactory$$Lambda$766/0x00000008015fe6f0.getObject(Unknown Source:-1)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:324)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200)
	at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:365)
	at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:135)
	at org.springframework.beans.factory.support.ConstructorResolver.resolveConstructorArguments(ConstructorResolver.java:696)
	at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:203)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1355)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1192)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.getSingletonFactoryBeanForTypeCheck(AbstractAutowireCapableBeanFactory.java:996)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.getTypeForFactoryBean(AbstractAutowireCapableBeanFactory.java:891)
	at org.springframework.beans.factory.support.AbstractBeanFactory.isTypeMatch(AbstractBeanFactory.java:621)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doGetBeanNamesForType(DefaultListableBeanFactory.java:575)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanNamesForType(DefaultListableBeanFactory.java:534)
	at org.springframework.beans.factory.BeanFactoryUtils.beanNamesForTypeIncludingAncestors(BeanFactoryUtils.java:260)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1637)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1397)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1353)
	at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:904)
	at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:782)
	at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:542)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1335)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1165)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:562)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:522)
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:326)
	at org.springframework.beans.factory.support.AbstractBeanFactory$$Lambda$766/0x00000008015fe6f0.getObject(Unknown Source:-1)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:324)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:205)
	at org.springframework.context.support.PostProcessorRegistrationDelegate.registerBeanPostProcessors(PostProcessorRegistrationDelegate.java:277)
	at org.springframework.context.support.AbstractApplicationContext.registerBeanPostProcessors(AbstractApplicationContext.java:805)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:608)
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:146)
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:754)
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:456)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:334)
	at com.xebialabs.xlrelease.XLReleaseBootstrapper$.main(XLReleaseBootstrapper.scala:182)
	at com.xebialabs.xlrelease.XLReleaseBootstrapper.main(XLReleaseBootstrapper.scala:-1)

I can see this is caused by meterRegistryPostProcessor trying to resolve application context:

I changed MetricsAutoConfiguration and MeterRegistryPostProcessor so that MeterRegistryPostProcessor implements ApplicationContextAware and does not need ApplicationContext as 1st constructor parameter - in that case I was able to avoid early application context initialization.

I cannot give a simple example because this happens in an old legacy app and I was unable to reproduce it outside of it.
If there is way to trace cause of this early initialization please let me know.

[wilkinsona]

Unfortunately, the stack trace isn't useful as, while it tells us that a series of beans is being created, it doesn't tell us what they are. You can figure that out using the debugger by walking back up the stack and looking at the value of the beanName parameter for each occurrence of ….createBean(AbstractAutowireCapableBeanFactory.java:522). If you can share with us those bean names plus details of how each is defined, we may be able to figure out the cause.

[ilx]

beans are:

• meterRegistryPostProcessor
• actorSystemHolder
• xlrDatabaseInformation
• sqlConfiguration
• databaseProxyFeature
• distributedFeaturesConfiguration

where actorSystemHolder is (most of the code is Scala codebase):

class ActorSystemHolder(xlrConfig: XlrConfig, @Qualifier("xlrDatabaseInformation") dbInfo: DatabaseInfo)
  extends Logging with ScalaSpringAwareBean with FactoryBean[ActorSystem] {

  private var running: Boolean = false

  lazy val actorSystem: ActorSystem = {
    info("Starting up actor system.")
    if (xlrConfig.isActiveOnStartup) {
      NodeState.setActive(true)
    }

    val pekkoConfig = getSlickConfig.withFallback(xlrConfig.pekko.config)
    val system = ActorSystem(xlrConfig.pekko.systemName, pekkoConfig)
    system.registerExtension(SpringExtension)
    running = true
    system
  }

  def shutdown(): Unit = {
    if (running) {
      info("Initiating actor system shutdown.")
      if (!AutoDowning.isDowning) {
        // Actor system should be terminated by Coordinated Shutdown Pekko extension
        val result = CoordinatedShutdown.get(actorSystem).run(GracefulShutdownReason)
        info("Waiting for actor system shutdown (indefinitely).")
        Await.result(result, atMost = Duration.Inf)
      }
      running = false
      info("Actor system shutdown finished.")
    }
  }

  override def getObject: ActorSystem = actorSystem

  override def getObjectType: Class[_] = classOf[ActorSystem]

DatabaseInfo is just a bean inside SqlConfiguration:

  @Bean
  def xlrDatabaseInformation: DatabaseInfo = {
    DatabaseInfo(xlrRepositoryDataSourceProxy())
  }

where it extracts database information via connection.getMetadata:

object DatabaseInfo {

  def apply(ds: DataSource): DatabaseInfo = {
    map(ds.getConnection) { connection =>
      val metadata = connection.getMetaData
      DatabaseInfo(metadata)
    }
  }

class SqlConfiguration(xlrConfig: XlrConfig,
                       databaseProxyFeature: DatabaseProxyFeature,
                       metricsTrackerFactory: MetricsTrackerFactory
                      )

DatabaseProxyFeature and MetricsTrackerFactory are making it a bit complicated but I can remove them. In that case list of beans is shorter:

• meterRegistryPostProcessor
• actorSystemHolder
• xlrDatabaseInformation
• sqlConfiguration

[wilkinsona]

Thanks for the details thus far. What's the bean that's being retrieved right at the bottom of the stack?

	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:205)
	at org.springframework.context.support.PostProcessorRegistrationDelegate.registerBeanPostProcessors(PostProcessorRegistrationDelegate.java:277)

[ilx]

Bean at the bottom of the stack is meterRegistryPostProcessor

[ilx]

Hmmm I noticed that the bean itself is configured via xml config:

    <bean id="actorSystemHolder" class="com.xebialabs.xlrelease.actors.ActorSystemHolder" destroy-method="shutdown"
          depends-on="beforeLiquibaseUpgrade">
        <constructor-arg name="xlrConfig" ref="xlrConfig"/>
        <constructor-arg name="dbInfo" ref="xlrDatabaseInformation" />
    </bean>

not sure if that makes difference

[wilkinsona]

It being defined in XML may make a difference. It may mean that the bean factory can't tell statically what type the com.xebialabs.xlrelease.actors.ActorSystemHolder factory bean will produce so it's being created really early to figure that out. Defining it in an @Configuration class may help with that as may using ObjectProvider to injects its arguments as injection into a FactoryBean is a known cause of problems:

• Intermittent BeanCurrentlyInCreationException when using @Autowired on a FactoryBean or anywhere in its dependency graph [SPR-9255] spring-framework#13893
• BeanPostProcessor can eagerly initialize factory beans that use constructor injection spring-framework#24553

The XML snippet also shows that beforeLiquibaseUpgrade is involved here too. That will affect things.

I'm afraid that we're going to need the complete picture here – and ideally a sample that reproduces the problem – to make any further progress.

Injecting the application context into the constructor should not be a problem as there's special handling for that and it isn't treated like a normal bean. We can't change that without a complete understanding of the problem as it may not be the optimal solution and it may have unwanted side-effects that we couldn't justify without a full understanding.