spring-boot 2.1.9 can used chaos-monkey-spring-boot which version

Expected Behavior

pass my test，spring-boot 2.1.9 project only can used chaos-monkey-spring-boot version is 2.0.0、2.0.1、2.0.2，can‘t used version is 2.1.1、2.2.0 and 2.3.0-SNAPSHOT.

Why support spring-boot 2.1.9 in 2.0.2 after version ?

Current Behavior

when i used 2.1.1 and after version， will thrown exception

2020-06-10 11:13:41.594 ERROR [test-project,main,] Error starting Tomcat context. Exception: org.springframework.beans.factory.BeanCreationException. Message: Error creating bean with name 'servletEndpointRegistrar' defined in class path resource [org/springframework/boot/actuate/autoconfigure/endpoint/web/ServletEndpointManagementContextConfiguration$WebMvcServletEndpointManagementContextConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.boot.actuate.endpoint.web.ServletEndpointRegistrar]: Factory method 'servletEndpointRegistrar' threw exception; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'chaosMonkeyRestEndpoint' defined in class path resource [de/codecentric/spring/boot/chaos/monkey/configuration/ChaosMonkeyConfiguration.class]: Unsatisfied dependency expressed through method 'chaosMonkeyRestEndpoint' parameter 1; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'scheduler' defined in class path resource [de/codecentric/spring/boot/chaos/monkey/configuration/ChaosMonkeyConfiguration.class]: Unsatisfied dependency expressed through method 'scheduler' parameter 0; nested exception is org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type 'org.springframework.scheduling.TaskScheduler' available: expected single matching bean but found 2: taskScheduler,catalogWatchTaskScheduler
2020-06-10 11:13:41.632  INFO [test-project,main,] Stopping service [Tomcat]
2020-06-10 11:13:41.650  WARN [test-project,main,] The web application [ROOT] appears to have started a thread named [AsyncReporter{KafkaSender{bootstrapServers=10.1.41.126:9092, topic=zipkin}}] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
 sun.misc.Unsafe.park(Native Method)
 java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:215)
 java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitNanos(AbstractQueuedSynchronizer.java:2078)
 zipkin2.reporter.ByteBoundedQueue.drainTo(ByteBoundedQueue.java:81)
 zipkin2.reporter.AsyncReporter$BoundedAsyncReporter.flush(AsyncReporter.java:257)
 zipkin2.reporter.AsyncReporter$Builder$1.run(AsyncReporter.java:190)
2020-06-10 11:13:41.650  WARN [test-project,main,] The web application [ROOT] appears to have started a thread named [Abandoned connection cleanup thread] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
 java.lang.Object.wait(Native Method)
 java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:144)
 com.mysql.jdbc.AbandonedConnectionCleanupThread.run(AbandonedConnectionCleanupThread.java:43)
2020-06-10 11:13:41.653  WARN [test-project,main,] Exception encountered during context initialization - cancelling refresh attempt: org.springframework.context.ApplicationContextException: Unable to start web server; nested exception is org.springframework.boot.web.server.WebServerException: Unable to start embedded Tomcat
2020-06-10 11:13:42.501  INFO [test-project,AsyncReporter{KafkaSender{bootstrapServers=10.1.41.126:9092, topic=zipkin}},] ProducerConfig values: 
	acks = 0
	batch.size = 16384
	bootstrap.servers = [10.1.41.126:9092]
	buffer.memory = 33554432
	client.id = 
	compression.type = none
	connections.max.idle.ms = 540000
	enable.idempotence = false
	interceptor.classes = []
	key.serializer = class org.apache.kafka.common.serialization.ByteArraySerializer
	linger.ms = 0
	max.block.ms = 60000
	max.in.flight.requests.per.connection = 5
	max.request.size = 1048576
	metadata.max.age.ms = 300000
	metric.reporters = []
	metrics.num.samples = 2
	metrics.recording.level = INFO
	metrics.sample.window.ms = 30000
	partitioner.class = class org.apache.kafka.clients.producer.internals.DefaultPartitioner
	receive.buffer.bytes = 32768
	reconnect.backoff.max.ms = 1000
	reconnect.backoff.ms = 50
	request.timeout.ms = 30000
	retries = 0
	retry.backoff.ms = 100
	sasl.client.callback.handler.class = null
	sasl.jaas.config = null
	sasl.kerberos.kinit.cmd = /usr/bin/kinit
	sasl.kerberos.min.time.before.relogin = 60000
	sasl.kerberos.service.name = null
	sasl.kerberos.ticket.renew.jitter = 0.05
	sasl.kerberos.ticket.renew.window.factor = 0.8
	sasl.login.callback.handler.class = null
	sasl.login.class = null
	sasl.login.refresh.buffer.seconds = 300
	sasl.login.refresh.min.period.seconds = 60
	sasl.login.refresh.window.factor = 0.8
	sasl.login.refresh.window.jitter = 0.05
	sasl.mechanism = GSSAPI
	security.protocol = PLAINTEXT
	send.buffer.bytes = 131072
	ssl.cipher.suites = null
	ssl.enabled.protocols = [TLSv1.2, TLSv1.1, TLSv1]
	ssl.endpoint.identification.algorithm = https
	ssl.key.password = null
	ssl.keymanager.algorithm = SunX509
	ssl.keystore.location = null
	ssl.keystore.password = null
	ssl.keystore.type = JKS
	ssl.protocol = TLS
	ssl.provider = null
	ssl.secure.random.implementation = null
	ssl.trustmanager.algorithm = PKIX
	ssl.truststore.location = null
	ssl.truststore.password = null
	ssl.truststore.type = JKS
	transaction.timeout.ms = 60000
	transactional.id = null
	value.serializer = class org.apache.kafka.common.serialization.ByteArraySerializer

2020-06-10 11:13:42.505  INFO [test-project,AsyncReporter{KafkaSender{bootstrapServers=10.1.41.126:9092, topic=zipkin}},] Kafka version : 2.0.1
2020-06-10 11:13:42.506  INFO [test-project,AsyncReporter{KafkaSender{bootstrapServers=10.1.41.126:9092, topic=zipkin}},] Kafka commitId : fa14705e51bd2ce5
2020-06-10 11:13:42.518  INFO [test-project,kafka-producer-network-thread | producer-1,] Cluster ID: nvkI2fgER1CCkbc3dB2DTQ
2020-06-10 11:13:42.528  INFO [test-project,main,] [Producer clientId=producer-1] Closing the Kafka producer with timeoutMillis = 9223372036854775807 ms.
2020-06-10 11:13:42.554  INFO [test-project,main,] 

Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2020-06-10 11:13:42.566 ERROR [test-project,main,] 

***************************
APPLICATION FAILED TO START
***************************

Description:

Parameter 0 of method scheduler in de.codecentric.spring.boot.chaos.monkey.configuration.ChaosMonkeyConfiguration required a single bean, but 2 were found:
	- taskScheduler: defined by method 'taskScheduler' in class path resource [org/springframework/boot/autoconfigure/task/TaskSchedulingAutoConfiguration.class]
	- catalogWatchTaskScheduler: defined by method 'catalogWatchTaskScheduler' in class path resource [org/springframework/cloud/consul/discovery/ConsulDiscoveryClientConfiguration.class]


Action:

Consider marking one of the beans as @Primary, updating the consumer to accept multiple beans, or using @Qualifier to identify the bean that should be consumed

Disconnected from the target VM, address: '127.0.0.1:58284', transport: 'socket'

Process finished with exit code 1

Possible Solution

i seed source code in ChaosMonkeyConfiguration.class

  @Bean
  public ChaosMonkeyScheduler scheduler(
      @Nullable TaskScheduler scheduler, ChaosMonkeyRuntimeScope runtimeScope) {
    ScheduledTaskRegistrar registrar = null;
    if (scheduler != null) {
      registrar = new ScheduledTaskRegistrar();
      registrar.setTaskScheduler(scheduler);
    }
    return new ChaosMonkeyScheduler(registrar, assaultProperties, runtimeScope);
  }

in this code, this statement of method , is compatible scheduler parameter is null，why add @Nullable annotation。

Steps to Reproduce

1. add pom.xml dependency。

        <dependency>
            <groupId>de.codecentric</groupId>
            <artifactId>chaos-monkey-spring-boot</artifactId>
            <version>2.3.0-SNAPSHOT</version>
        </dependency>

1. add program run parameter

--spring.profiles.active=chaos-monkey

1. start project

Context (Environment)

os: macOS 10.15.3 JDK: 1.8.0_231-b11 spring-boot: 2.1.9 spring-cloud : 2.1.0

[liquanjin]

Hi, @WtfJoke . Thank your reply 。

Your reply given me some idea to fix this question。

At this same time，i think this question：chaos-monkey-spring-boot depend TaskScheduler Bean，Why chaos-monkey-spring-boot can’t configure a TaskScheduler Bean by myself，But rely on external TaskScheduler Bean。

I think defined a TaskScheduler Bean by myself is best way to fix this question。

[maiksensi]

hey @liquanjin, this seems answered. If you have other questions, feel free to ask them on stackoverflow as we tend to use that for questions regarding the usage. If you think your issue is a bug, please open a new one, and we can discuss the details there.