Feign client lazy initialization fails when using CompletableFuture.supplyAsync() to call the Feign client initially #475

maverick1601 · 2021-01-28T12:42:42Z

Describe the bug
Feign client initialization is always lazy. As such, the first calling thread triggers the initialization, which may be another Spring component (e.g. REST controller) using CompletableFuture.supplyAsync() to do so. This uses ForkJoinWorkerThread underneath, resulting in a ClassNotFoundException, if and only if running in a dockerized environment based on Spring Boot Build Image plugin.

Using other JVM Executors(except newWorkStealingExecutor), e.g. fixedSizeThreadExecutor(), does not result in this behavior. Also eagerly initializing the Feign client by calling it synchronously, e.g. from within a CommandLineRunner, circumvents this. Once, the Feign client is properly initialized, there is no problem, however, Feign does not yet support eager initialization.

Sample
A sample project with instructions to reproduce is provided here: https://github.com/maverick1601/openfeign-build-image-error

The text was updated successfully, but these errors were encountered:

OlgaMaciaszek · 2021-01-29T14:28:25Z

I was able to reproduce it with the sample. Example stacktrace:

 java.lang.ClassNotFoundException: org.springframework.boot.autoconfigure.condition.OnPropertyCondition
      at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(Unknown Source) ~[na:na]
      at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(Unknown Source) ~[na:na]
      at java.base/java.lang.ClassLoader.loadClass(Unknown Source) ~[na:na]
      at java.base/java.lang.Class.forName0(Native Method) ~[na:na]
      at java.base/java.lang.Class.forName(Unknown Source) ~[na:na]
      at org.springframework.util.ClassUtils.forName(ClassUtils.java:284) ~[spring-core-5.3.3.jar:5.3.3]
      at org.springframework.util.ClassUtils.resolveClassName(ClassUtils.java:324) ~[spring-core-5.3.3.jar:5.3.3]
      at org.springframework.context.annotation.ConditionEvaluator.getCondition(ConditionEvaluator.java:124) ~[spring-context-5.3.3.jar:5.3.3]
      at org.springframework.context.annotation.ConditionEvaluator.shouldSkip(ConditionEvaluator.java:96) ~[spring-context-5.3.3.jar:5.3.3]
      at org.springframework.context.annotation.ConditionEvaluator.shouldSkip(ConditionEvaluator.java:88) ~[spring-context-5.3.3.jar:5.3.3]
      at org.springframework.context.annotation.ConditionEvaluator.shouldSkip(ConditionEvaluator.java:71) ~[spring-context-5.3.3.jar:5.3.3]
       at org.springframework.context.annotation.AnnotatedBeanDefinitionReader.doRegisterBean(AnnotatedBeanDefinitionReader.java:254) ~[spring-context-5.3.3.jar:5.3.3]
       at org.springframework.context.annotation.AnnotatedBeanDefinitionReader.registerBean(AnnotatedBeanDefinitionReader.java:147) ~[spring-context-5.3.3.jar:5.3.3]
       at org.springframework.context.annotation.AnnotatedBeanDefinitionReader.register(AnnotatedBeanDefinitionReader.java:137) ~[spring-context-5.3.3.jar:5.3.3]
      at org.springframework.context.annotation.AnnotationConfigApplicationContext.register(AnnotationConfigApplicationContext.java:168) ~[spring-context-5.3.3.jar:5.3.3]
      at org.springframework.cloud.context.named.NamedContextFactory.createContext(NamedContextFactory.java:122) ~[spring-cloud-context-3.0.1.jar:3.0.1]
      at org.springframework.cloud.context.named.NamedContextFactory.getContext(NamedContextFactory.java:101) ~[spring-cloud-context-3.0.1.jar:3.0.1]
       at org.springframework.cloud.context.named.NamedContextFactory.getInstances(NamedContextFactory.java:181) ~[spring-cloud-context-3.0.1.jar:3.0.1]
       at org.springframework.cloud.openfeign.loadbalancer.FeignBlockingLoadBalancerClient.execute(FeignBlockingLoadBalancerClient.java:85) ~[spring-cloud-openfeign-core-3.0.1.jar:3.0.1]
      at feign.SynchronousMethodHandler.executeAndDecode(SynchronousMethodHandler.java:119) ~[feign-core-10.10.1.jar:na]
       at feign.SynchronousMethodHandler.invoke(SynchronousMethodHandler.java:89) ~[feign-core-10.10.1.jar:na]
       at feign.ReflectiveFeign$FeignInvocationHandler.invoke(ReflectiveFeign.java:100) ~[feign-core-10.10.1.jar:na]
       at com.sun.proxy.$Proxy73.fetchIt(Unknown Source) ~[na:na]
       at de.digitalfrontiers.spring.build.image.SampleController$sampleApi$1.get(SampleController.kt:14) ~[classes/:na]
       at de.digitalfrontiers.spring.build.image.SampleController$sampleApi$1.get(SampleController.kt:9) ~[classes/:na]
      at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(Unknown Source) ~[na:na]
       at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.exec(Unknown Source) ~[na:na]
       at java.base/java.util.concurrent.ForkJoinTask.doExec(Unknown Source) ~[na:na]
       at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(Unknown Source) ~[na:na]
       at java.base/java.util.concurrent.ForkJoinPool.scan(Unknown Source) ~[na:na]
       at java.base/java.util.concurrent.ForkJoinPool.runWorker(Unknown Source) ~[na:na]
       at java.base/java.util.concurrent.ForkJoinWorkerThread.run(Unknown Source) ~[na:na]

OlgaMaciaszek · 2021-01-29T14:31:13Z

@maverick1601, thanks for reporting this. Will discuss it with the team and get back to you.

OlgaMaciaszek · 2021-02-18T16:07:53Z

@maverick1601 we don't recommend using CompletableFuture.supplyAsync(), however, an enhancement that could be helpful here would be to offer an opt-in eager-loading mechanism. We don't think it's a priority at this point, so we would not work on this right now, however, we would welcome pull requests. As a reference, here is a PR, that introduced eager-loading in SC Ribbon where child contexts were being lazily initialised, very similarly to what we have in OpenFeign: spring-cloud/spring-cloud-netflix@567a6c4.

davgia · 2021-10-04T16:20:21Z

Hi, is there any news about this issue and the associated PR? I encountered a similar issue when using openfeign client called within a method annotated as @Async that uses a ForkJoinPool executor (spring-boot: 2.5.5, spring-cloud: 2020.0.4). I have yet to find a solution or workaround.

P.S. I think it's related to #600

P.S.S. I've tried the solution described in #600 and I managed to make it working. I hope that it can be fixed asap because it's not only a openfeign issue but it does apply on LoadBalanced RestTemplates too

OlgaMaciaszek · 2021-10-28T16:28:06Z

This issue is not within the team's priorities right now, but is open to community contributions.

mgrigis · 2022-03-01T17:34:44Z

An alternative solution is to use rxjava,

mvn dep

io.reactivex rxjava

…t more aggressively. `ConditionEvaluator` extracts the class loader from the bean factory at instantiation, and then uses said classloader to load classes when evaluating conditionals. Hence, we need to inject the parent class loader into a bean factory that we inject into the child context. This fix is an extension of the fix made in spring-cloud/spring-cloud-netflix#3101. Fixes spring-cloud/spring-cloud-openfeign#475

DenisKorolev · 2022-04-28T07:25:49Z

The previous workaround didn't work for me as the constructor of LoadBalancerClientFactory without arguments is deprecated, as a result that solution causes NPE.

Here is the modified version:

    @Bean
    @ConditionalOnMissingBean
    public LoadBalancerClientFactory loadBalancerClientFactory(LoadBalancerClientsProperties properties) {
        return new LoadBalancerClientFactory(properties) {
            @Override
            protected AnnotationConfigApplicationContext createContext(String name) {
                // FIXME: temporary switch classloader to use the correct one when creating the context
                ClassLoader originalClassLoader = Thread.currentThread().getContextClassLoader();
                Thread.currentThread().setContextClassLoader(this.getClass().getClassLoader());
                AnnotationConfigApplicationContext context = super.createContext(name);
                Thread.currentThread().setContextClassLoader(originalClassLoader);
                return context;
            }
        };
    }

timosmit · 2022-05-10T06:28:14Z

The previous workaround didn't work for me as the constructor of LoadBalancerClientFactory without arguments is deprecated, as a result that solution causes NPE.

@DenisKorolev is there any particular reason why you have omitted the following line from the previous workaround?

clientFactory.setConfigurations(configurations.getIfAvailable(Collections::emptyList));

This line still appears in the org.springframework.cloud.loadbalancer.config.LoadBalancerAutoConfiguration.

DDAaTao · 2022-09-02T02:34:10Z

My problem like it, #1139

But my problem is deadlock, Maybe it's the same thing with different consequences

Found one Java-level deadlock:
=============================
"ForkJoinPool.commonPool-worker-2":
  waiting to lock monitor 0x000000002c456c18 (object 0x00000005c2284aa8, a java.util.concurrent.ConcurrentHashMap),
  which is held by "main"
"main":
  waiting to lock monitor 0x000000002bda1db8 (object 0x000000071649d0e0, a java.util.concurrent.ConcurrentHashMap),
  which is held by "ForkJoinPool.commonPool-worker-2"

Java stack information for the threads listed above:
===================================================
"ForkJoinPool.commonPool-worker-2":
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:179)
        - waiting to lock <0x00000005c2284aa8> (a java.util.concurrent.ConcurrentHashMap)
        at org.springframework.beans.factory.support.AbstractBeanFactory.isTypeMatch(AbstractBeanFactory.java:493)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.doGetBeanNamesForType(DefaultListableBeanFactory.java:520)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanNamesForType(DefaultListableBeanFactory.java:491)
        at org.springframework.beans.factory.BeanFactoryUtils.beanNamesForTypeIncludingAncestors(BeanFactoryUtils.java:227)
        at org.springframework.beans.factory.BeanFactoryUtils.beanNamesForTypeIncludingAncestors(BeanFactoryUtils.java:231)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1419)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1218)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1175)
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostPro
cessor.java:595)
        at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:90)
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.
java:376)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1404)      
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:592)       
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515)
        at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320)
        at org.springframework.beans.factory.support.AbstractBeanFactory$$Lambda$162/2081000371.getObject(Unknown Source)
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
        - locked <0x000000071a98c5a8> (a java.util.concurrent.ConcurrentHashMap)
        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:847)
        at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:877)
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549)
        - locked <0x000000071a98c200> (a java.lang.Object)
        at org.springframework.cloud.context.named.NamedContextFactory.createContext(NamedContextFactory.java:136)
        at org.springframework.cloud.context.named.NamedContextFactory.getContext(NamedContextFactory.java:101)
        - locked <0x000000071649d0e0> (a java.util.concurrent.ConcurrentHashMap)
        at org.springframework.cloud.netflix.ribbon.SpringClientFactory.getContext(SpringClientFactory.java:131)
        at org.springframework.cloud.context.named.NamedContextFactory.getInstance(NamedContextFactory.java:145)
        at org.springframework.cloud.netflix.ribbon.SpringClientFactory.getInstance(SpringClientFactory.java:121)
        at org.springframework.cloud.netflix.ribbon.SpringClientFactory.getClientConfig(SpringClientFactory.java:75)
        at org.springframework.cloud.openfeign.ribbon.LoadBalancerFeignClient.getClientConfig(LoadBalancerFeignClient.java:97)
        at org.springframework.cloud.openfeign.ribbon.LoadBalancerFeignClient.execute(LoadBalancerFeignClient.java:81)
        at feign.SynchronousMethodHandler.executeAndDecode(SynchronousMethodHandler.java:110)
        at feign.SynchronousMethodHandler.invoke(SynchronousMethodHandler.java:80)
        at feign.ReflectiveFeign$FeignInvocationHandler.invoke(ReflectiveFeign.java:103)
        at com.sun.proxy.$Proxy154.getPersonOne(Unknown Source)
        at com.siiri.cts.open.biz.config.TestDeadLockConfig.lambda$initBean$0(TestDeadLockConfig.java:28)
        at com.siiri.cts.open.biz.config.TestDeadLockConfig$$Lambda$565/2000449863.run(Unknown Source)
        at java.util.concurrent.CompletableFuture$AsyncRun.run$$$capture(CompletableFuture.java:1626)
        at java.util.concurrent.CompletableFuture$AsyncRun.run(CompletableFuture.java)
        at java.util.concurrent.CompletableFuture$AsyncRun.exec(CompletableFuture.java:1618)
        at java.util.concurrent.ForkJoinTask.doExec$$$capture(ForkJoinTask.java:289)
        at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java)
        at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1056)
        at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1692)
        at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:157)
"main":
        at org.springframework.cloud.context.named.NamedContextFactory.getContext(NamedContextFactory.java:100)
        - waiting to lock <0x000000071649d0e0> (a java.util.concurrent.ConcurrentHashMap)
        at org.springframework.cloud.netflix.ribbon.SpringClientFactory.getContext(SpringClientFactory.java:131)
        at org.springframework.cloud.context.named.NamedContextFactory.getInstance(NamedContextFactory.java:145)
        at org.springframework.cloud.netflix.ribbon.SpringClientFactory.getInstance(SpringClientFactory.java:121)
        at org.springframework.cloud.netflix.ribbon.SpringClientFactory.getClientConfig(SpringClientFactory.java:75)
        at org.springframework.cloud.openfeign.ribbon.LoadBalancerFeignClient.getClientConfig(LoadBalancerFeignClient.java:97)
        at org.springframework.cloud.openfeign.ribbon.LoadBalancerFeignClient.execute(LoadBalancerFeignClient.java:81)
        at feign.SynchronousMethodHandler.executeAndDecode(SynchronousMethodHandler.java:110)
        at feign.SynchronousMethodHandler.invoke(SynchronousMethodHandler.java:80)
        at feign.ReflectiveFeign$FeignInvocationHandler.invoke(ReflectiveFeign.java:103)
        at com.sun.proxy.$Proxy153.getByAccountName(Unknown Source)
        at com.siiri.cts.open.biz.config.TestDeadLockConfig.initBean(TestDeadLockConfig.java:33)
        at com.siiri.cts.open.biz.config.TestDeadLockConfig$$EnhancerBySpringCGLIB$$3776b5f.CGLIB$initBean$0(<generated>)
        at com.siiri.cts.open.biz.config.TestDeadLockConfig$$EnhancerBySpringCGLIB$$3776b5f$$FastClassBySpringCGLIB$$bc6c3884.invoke(<generated>)       
        at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:244)
        at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:363)       
        at com.siiri.cts.open.biz.config.TestDeadLockConfig$$EnhancerBySpringCGLIB$$3776b5f.initBean(<generated>)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154)
        at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:622)
        at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:456)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory
.java:1320)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1159)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555)       
        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.AbstractBeanFactory$$Lambda$162/2081000371.getObject(Unknown Source)
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
        - locked <0x00000005c2284aa8> (a java.util.concurrent.ConcurrentHashMap)
        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:847)
        at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:877)
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549)
        - locked <0x00000005c23cb290> (a java.lang.Object)
        at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141)
        at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:744)
        at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:391)
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:312)
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1215)
        at org.springframework.boot.SpringApplication.run(SpringApplication.java:1204)
        at com.siiri.cts.open.web.OpenServiceWebApplication.main(OpenServiceWebApplication.java:42)

Found 1 deadlock.

HJK181 · 2022-10-05T06:10:33Z

I'm facing the exact same problem after an update from Spring 2.3 to Spring 2.7 + Java update from 14 to 17.
We are not using any @async or CompletableFuture, but the feign client is called by a Grizzly Thread (started as part of a Spring Boot app) that is part of our core infrastructure and needs to call another running Spring Boot app via Feign. This used to work without any problems before the update. Disappointed way too often to see such an issue open for such a long time with no prospect of a solution

Psimage · 2022-10-30T00:02:58Z

Made another sample project that reproduces a problem. It also contains a submodule with proposed workaround by @DenisKorolev. There are also a test with boot 2.3 and ribbon that works fine and a test for when eager-loading enabled for Spring's loadbalancer (available in boot 3+, but you can implement the same logic for yourself if it fits).

ruanun · 2022-10-31T09:02:51Z

Hi. In what version was the "openfeign asynchronous call error "problem fixed?

OlgaMaciaszek · 2022-10-31T11:13:31Z

This issue is still open.

SuperChrisliu · 2022-12-01T06:08:37Z

Made another sample project that reproduces a problem. It also contains a submodule with proposed workaround by @DenisKorolev. There are also a test with boot 2.3 and ribbon that works fine and a test for when eager-loading enabled for Spring's loadbalancer (available in boot 3+, but you can implement the same logic for yourself if it fits).

use maven package to jar file then run jar , it get ClassNotFoundException

will not get ClassNotFoundException while not use jar file run

poolsnowhui · 2023-02-07T06:19:44Z

linux in docker had the problem in jdk17, but windows was ok in jdk17.

nicolasArmando · 2023-02-28T10:58:44Z

I wanted to share some information about some similar bug.

We have one spring service working with docker, k8, java 17 and the use of CompletableFuture, everything was working ok, until we decided to add more memory and cpu

We pass from

resources:
  requests:
    memory: "64Mi"
    cpu: "48m"
  limits:
    memory: "512Mi"
    cpu: "1000m"

To

  resources:
    requests:
      memory: "512Mi"
      cpu: "60m"
    limits:
      memory: "512Mi"

And the same bug appear Could not find class [org.springframework.boot.autoconfigure.condition.OnBeanCondition] the classLoader was almost empty, like we pass from 15000 class to 50 in the classLoader.

But the the code was related to StreamBridge and not feign client (even if we use it in the code, but not directly in the code called), but for me is the same JVM/spring bug. Is was working ok with the IDE, but the Jar was failing, etc

The solution put in place was add

@Configuration
public class TaskExecutorConfig {

  @Bean("asyncPool")
  public Executor asyncPool() {

    return Executors.newFixedThreadPool(10);
  }
}

And pass it when we call the CompletableFuture

CompletableFuture.runAsync(
  () -> {
                your code here...
            },
  asyncPool
);

eldzej88 · 2023-03-31T13:38:46Z

Another workaround is manually init load balancer clients, for example after application ready event occured

@Configuration
@RequiredArgsConstructor
public class LoadBalancerClientsInitializer {

    private final LoadBalancerClientFactory loadBalancerClientFactory;

    @EventListener(ApplicationReadyEvent.class)
    public void onApplicationReadyEvent() {
        loadBalancerClientFactory.getInstance("client-name", NONE);
    }

}

@FeignClient(name = "client-name", contextId = "someClient")
public interface SomeClient {
}

kisick · 2023-04-15T10:48:13Z

The previous workaround didn't work for me as the constructor of LoadBalancerClientFactory without arguments is deprecated, as a result that solution causes NPE.

@DenisKorolev is there any particular reason why you have omitted the following line from the previous workaround?
clientFactory.setConfigurations(configurations.getIfAvailable(Collections::emptyList));
This line still appears in the org.springframework.cloud.loadbalancer.config.LoadBalancerAutoConfiguration.

If you have a custom loadbalancer configure, like
@LoadBalancerClients(defaultConfiguration = CustomLoadBalancerConfiguration.class)
you should add it
loadBalancerClientFactory.setConfigurations(configurations.getIfAvailable(Collections::emptyList));

    @Bean
    @ConditionalOnMissingBean
    public LoadBalancerClientFactory loadBalancerClientFactory(LoadBalancerClientsProperties properties, ObjectProvider<List<LoadBalancerClientSpecification>> configurations) {
        LoadBalancerClientFactory loadBalancerClientFactory = new LoadBalancerClientFactory(properties) {
            @Override
            protected AnnotationConfigApplicationContext createContext(String name) {
                // FIXME: temporary switch classloader to use the correct one when creating the context
                ClassLoader originalClassLoader = Thread.currentThread().getContextClassLoader();
                Thread.currentThread().setContextClassLoader(this.getClass().getClassLoader());
                AnnotationConfigApplicationContext context = super.createContext(name);
                Thread.currentThread().setContextClassLoader(originalClassLoader);
                return context;
            }
        };
        loadBalancerClientFactory.setConfigurations(configurations.getIfAvailable(Collections::emptyList));
        return loadBalancerClientFactory;
    }

HJK181 · 2023-04-17T05:44:37Z

We experience the same issue with k8s resource limits. After we removed the CPU limit of 1, our application failed to execute Feign requests as the POD where the application runs now had more CPUs visible to the JVM. 4 instead of 1. I'm wondering why the Spring team does not see this as a serious issue as the usage of CompletableFuture in a project is very likely and we have numerous comments here with lots of related issues that were closed ...

badrkacimi · 2023-06-26T11:31:49Z

Spring boot 3.1.0
spring-cloud 2022.0.3
Java 17

The previous workaround is working with little changes

 @Bean
  @ConditionalOnMissingBean
  public LoadBalancerClientFactory loadBalancerClientFactory(LoadBalancerClientsProperties properties) {
    return new LoadBalancerClientFactory(properties) {
      @Override public AnnotationConfigApplicationContext createContext(String name) {
        ClassLoader originalClassLoader = Thread.currentThread().getContextClassLoader();
        Thread.currentThread().setContextClassLoader(this.getClass().getClassLoader());
        AnnotationConfigApplicationContext context = (AnnotationConfigApplicationContext) super.createContext(name);
        Thread.currentThread().setContextClassLoader(originalClassLoader);
        return context;
      }
    };
  }

crmky · 2023-07-07T06:15:57Z

We got similar issue in one of our applications. After investigation, we found this is caused by https://bugs.openjdk.org/browse/JDK-8172726.

Start with Java 9, ForkJoinPool creates thread using system class loader as context class loader, refer to https://github.com/openjdk/jdk11u/blob/master/src/java.base/share/classes/java/util/concurrent/ForkJoinPool.java#L721.

If we run applications in IDE, the system class loader has been used to load Spring and application classes, so it's not easy to reproduce this issue. If we run applications from command line using fat JAR, org.springframework.boot.loader.LaunchedURLClassLoader will be used to load those classes instead. If threads switch to use system class loader, it will not be able to load Spring and other classes inside the fat JAR.

crmky · 2023-07-07T08:55:54Z

The fix in spring-cloud/spring-cloud-commons#1098 tries to use the class loader of parent ApplicationContext in child ApplicationContext:

context = new AnnotationConfigApplicationContext(beanFactory);
context.setClassLoader(this.parent.getClassLoader());

However typically the parent ApplicationContext doesn't set class loader explicitly, it will use ClassUtils.getDefaultClassLoader() to return the default class loader. Unfortunately that implementation will return context class loader if that has been set.

crmky · 2023-07-07T23:52:44Z

Our applications use a different workaround. We created ApplicationContextInitializer implementation (and added to spring.factories) to manually set the class loader as the context class loader who starts the application.

public class ClassLoaderApplicationContextInitializer
        implements ApplicationContextInitializer<ConfigurableApplicationContext> {

    @Override
    public void initialize(ConfigurableApplicationContext applicationContext) {
        applicationContext.setClassLoader(applicationContext.getClassLoader());
    }
}

OlgaMaciaszek · 2023-07-19T17:22:56Z

Thanks for looking into it @crmky. Have submitted a PR to address this in Commons.

OlgaMaciaszek · 2023-07-20T08:43:36Z

Fixed with spring-cloud/spring-cloud-commons#1256.

spring-cloud-issues added the waiting-for-triage label Jan 28, 2021

OlgaMaciaszek added for team discussion and removed waiting-for-triage labels Jan 29, 2021

OlgaMaciaszek added enhancement New feature or request help wanted Extra attention is needed and removed for team discussion labels Feb 18, 2021

Periecle mentioned this issue Mar 14, 2021

GH-475: Optional Feign clients eager initialization mechanism #512

Closed

OlgaMaciaszek mentioned this issue Oct 28, 2021

ClassNotFoundException when calling a FeignBlockingLoadBalancerClient in a parallel stream (multiple threads) #600

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tommyk-gears mentioned this issue Apr 19, 2022

Inject the class loader from the parent context into the child context spring-cloud/spring-cloud-commons#1098

Merged

OlgaMaciaszek added this to To do in 2021.0.2 via automation Apr 21, 2022

OlgaMaciaszek added this to To do in 2022.0.0-M3 via automation Apr 21, 2022

OlgaMaciaszek moved this from To do to In progress in 2021.0.2 Apr 21, 2022

OlgaMaciaszek moved this from To do to In progress in 2022.0.0-M3 Apr 21, 2022

OlgaMaciaszek added this to the 3.1.2 milestone Apr 21, 2022

spencergibb removed this from In progress in 2021.0.2 May 5, 2022

spencergibb added this to To do in 2021.0.3 via automation May 5, 2022

spencergibb removed this from the 3.1.2 milestone May 5, 2022

spencergibb removed this from To do in 2021.0.3 May 27, 2022

spencergibb added this to To do in 2021.0.4 via automation May 27, 2022

ryanjbaxter removed this from In progress in 2022.0.0-M3 Jun 15, 2022

OlgaMaciaszek mentioned this issue Sep 2, 2022

CompletableFuture create client triggered a deadlock spring-cloud/spring-cloud-commons#1139

Closed

ryanjbaxter removed this from To do in 2021.0.4 Sep 7, 2022

cemthecebi mentioned this issue Sep 28, 2022

IllegalArgumentException, Could not find class error #771

Closed

HJK181 mentioned this issue Oct 6, 2022

Asynchronous deserialization performed by Hazelcast may fail due to the wrong ClassLoader being used spring-projects/spring-boot#24836

Closed

HJK181 mentioned this issue Oct 17, 2022

java.lang.IllegalArgumentException: Could not find class [org.springframework.boot.autoconfigure.condition.OnPropertyCondition] #740

Closed

OlgaMaciaszek mentioned this issue Feb 20, 2023

when use jdk17，the OnPropertyCondition of @FeignClient is class not found. #801

Closed

OlgaMaciaszek mentioned this issue Jul 19, 2023

Use classloader from class. spring-cloud/spring-cloud-commons#1256

Merged

OlgaMaciaszek added this to the 3.1.9 milestone Jul 19, 2023

OlgaMaciaszek removed the help wanted Extra attention is needed label Jul 19, 2023

OlgaMaciaszek self-assigned this Jul 19, 2023

OlgaMaciaszek closed this as completed Jul 20, 2023

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Feign client lazy initialization fails when using CompletableFuture.supplyAsync() to call the Feign client initially #475

Feign client lazy initialization fails when using CompletableFuture.supplyAsync() to call the Feign client initially #475

maverick1601 commented Jan 28, 2021 •

edited by OlgaMaciaszek

OlgaMaciaszek commented Jan 29, 2021 •

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SuperChrisliu commented Dec 1, 2022 •

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poolsnowhui commented Feb 7, 2023

nicolasArmando commented Feb 28, 2023 •

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eldzej88 commented Mar 31, 2023

kisick commented Apr 15, 2023

HJK181 commented Apr 17, 2023 •

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badrkacimi commented Jun 26, 2023

crmky commented Jul 7, 2023 •

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crmky commented Jul 7, 2023

crmky commented Jul 7, 2023

OlgaMaciaszek commented Jul 19, 2023

OlgaMaciaszek commented Jul 20, 2023

Feign client lazy initialization fails when using CompletableFuture.supplyAsync() to call the Feign client initially #475

Feign client lazy initialization fails when using CompletableFuture.supplyAsync() to call the Feign client initially #475

Comments

maverick1601 commented Jan 28, 2021 • edited by OlgaMaciaszek

OlgaMaciaszek commented Jan 29, 2021 • edited

OlgaMaciaszek commented Jan 29, 2021

OlgaMaciaszek commented Feb 18, 2021

davgia commented Oct 4, 2021 • edited

OlgaMaciaszek commented Oct 28, 2021

mgrigis commented Mar 1, 2022

DenisKorolev commented Apr 28, 2022 • edited

timosmit commented May 10, 2022

DDAaTao commented Sep 2, 2022 • edited

HJK181 commented Oct 5, 2022 • edited

Psimage commented Oct 30, 2022 • edited

ruanun commented Oct 31, 2022

OlgaMaciaszek commented Oct 31, 2022

SuperChrisliu commented Dec 1, 2022 • edited

poolsnowhui commented Feb 7, 2023

nicolasArmando commented Feb 28, 2023 • edited

eldzej88 commented Mar 31, 2023

kisick commented Apr 15, 2023

HJK181 commented Apr 17, 2023 • edited

badrkacimi commented Jun 26, 2023

crmky commented Jul 7, 2023 • edited

crmky commented Jul 7, 2023

crmky commented Jul 7, 2023

OlgaMaciaszek commented Jul 19, 2023

OlgaMaciaszek commented Jul 20, 2023

maverick1601 commented Jan 28, 2021 •

edited by OlgaMaciaszek

OlgaMaciaszek commented Jan 29, 2021 •

edited

davgia commented Oct 4, 2021 •

edited

DenisKorolev commented Apr 28, 2022 •

edited

DDAaTao commented Sep 2, 2022 •

edited

HJK181 commented Oct 5, 2022 •

edited

Psimage commented Oct 30, 2022 •

edited

SuperChrisliu commented Dec 1, 2022 •

edited

nicolasArmando commented Feb 28, 2023 •

edited

HJK181 commented Apr 17, 2023 •

edited

crmky commented Jul 7, 2023 •

edited