Skip to content

The Kafka topic is here, a Java consumer program finds it, but lists none of its content, while a kafka-console-consumer is able to

It’s my first Kafka program.

From a kafka_2.13-3.1.0 instance, I created a Kafka topic poids_garmin_brut and filled it with this csv:

kafka-topics.sh --create --bootstrap-server localhost:9092 --replication-factor 1 --partitions 1 --topic poids_garmin_brut
kafka-console-producer.sh --broker-list localhost:9092 --topic poids_garmin_brut < "Poids(1).csv"
Durée,Poids,Variation,IMC,Masse grasse,Masse musculaire squelettique,Masse osseuse,Masse hydrique,
" 14 Fév. 2022",
06:37,72.1 kg,0.3 kg,22.8,26.3 %,29.7 kg,3.5 kg,53.8 %,
" 13 Fév. 2022",
06:48,72.4 kg,0.2 kg,22.9,25.4 %,29.8 kg,3.6 kg,54.4 %,
" 12 Fév. 2022",
06:17,72.2 kg,0.0 kg,22.8,25.3 %,29.7 kg,3.6 kg,54.5 %,
[...]

And at anytime now, before or after running the program I’ll show, its content can be displayed by a kafka-console-consumer command:

kafka-console-consumer.sh --bootstrap-server localhost:9092 --topic poids_garmin_brut --from-beginning
Durée,Poids,Variation,IMC,Masse grasse,Masse musculaire squelettique,Masse osseuse,Masse hydrique,
" 14 Fév. 2022",
06:37,72.1 kg,0.3 kg,22.8,26.3 %,29.7 kg,3.5 kg,53.8 %,
" 13 Fév. 2022",
06:48,72.4 kg,0.2 kg,22.9,25.4 %,29.8 kg,3.6 kg,54.4 %,
" 12 Fév. 2022",
06:17,72.2 kg,0.0 kg,22.8,25.3 %,29.7 kg,3.6 kg,54.5 %,
" 11 Fév. 2022",
05:54,72.2 kg,0.1 kg,22.8,25.6 %,29.7 kg,3.5 kg,54.3 %,
" 10 Fév. 2022",
06:14,72.3 kg,0.0 kg,22.8,25.9 %,29.7 kg,3.5 kg,54.1 %,
" 9 Fév. 2022",
06:06,72.3 kg,0.5 kg,22.8,26.3 %,29.7 kg,3.5 kg,53.8 %,
" 8 Fév. 2022",
07:14,71.8 kg,0.7 kg,22.7,26.3 %,29.6 kg,3.5 kg,53.8 %,

Here is the Java program, based on org.apache.kafka:kafka-streams:3.1.0 dependency, extracting this topic as a stream:

package extracteur.garmin;

import org.apache.kafka.clients.consumer.ConsumerConfig;
import org.apache.kafka.common.serialization.Serdes;
import org.apache.kafka.streams.KafkaStreams;
import org.apache.kafka.streams.StreamsBuilder;
import org.apache.kafka.streams.StreamsConfig;
import org.apache.kafka.streams.kstream.KStream;
import org.slf4j.*;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import java.util.Properties;

@SpringBootApplication
public class Kafka {
   /** Logger. */
   private static final Logger LOGGER = LoggerFactory.getLogger(Kafka.class);

   public static void main(String[] args) {
      LOGGER.info("L'extracteur de données Garmin démarre...");

      /* Les données du fichier CSV d'entrée sont sous cette forme :

         Durée,Poids,Variation,IMC,Masse grasse,Masse musculaire squelettique,Masse osseuse,Masse hydrique,
         " 14 Fév. 2022",
         06:37,72.1 kg,0.3 kg,22.8,26.3 %,29.7 kg,3.5 kg,53.8 %,
         " 13 Fév. 2022",
         06:48,72.4 kg,0.2 kg,22.9,25.4 %,29.8 kg,3.6 kg,54.4 %,
       */

      // Création d'un flux sans clef et valeur : chaîne de caractères.
      StreamsBuilder builder = new StreamsBuilder();
      KStream<Void,String> stream = builder.stream("poids_garmin_brut");

      // C'est un foreach de Kafka, pas de lambda java. Il est lazy.
      stream.foreach((key, value) -> {
         LOGGER.info(value);
      });

      KafkaStreams streams = new KafkaStreams(builder.build(), config());
      streams.start();

      // Fermer le flux Kafka quand la VM s'arrêtera, en faisant appeler
      streams.close();
      Runtime.getRuntime().addShutdownHook(new Thread(streams::close));
   }

   /**
    * Propriétés pour le démarrage.
    * @return propriétés de configuration.
    */
   private static Properties config() {
      Properties config = new Properties();
      config.put(StreamsConfig.APPLICATION_ID_CONFIG, "dev1");
      config.put(StreamsConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092");
      config.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
      config.put(StreamsConfig.DEFAULT_KEY_SERDE_CLASS_CONFIG, Serdes.Void().getClass());
      config.put(StreamsConfig.DEFAULT_VALUE_SERDE_CLASS_CONFIG, Serdes.String().getClass());
      return config;
   }
}

But, while the logs don’t seem to report any error during execution, my program doesn’t enter the stream.forEach, and therefore: displays no content from that topic.

(in this log I removed the dev1-d1c8ce47-6fbf-41b7-b8aa-e3d094703088- part of [dev1-d1c8ce47-6fbf-41b7-b8aa-e3d094703088-StreamThread-1] you should read inside, for SO message length and lisibility. And org.apache.kafka becames o.a.k.).

/usr/lib/jvm/java-1.11.0-openjdk-amd64/bin/java -XX:TieredStopAtLevel=1 -noverify -Dspring.output.ansi.enabled=always -Dcom.sun.management.jmxremote -Dspring.jmx.enabled=true -Dspring.liveBeansView.mbeanDomain -Dspring.application.admin.enabled=true -javaagent:/opt/idea-IU-212.5284.40/lib/idea_rt.jar=41397:/opt/idea-IU-212.5284.40/bin -Dfile.encoding=UTF-8 -classpath /home/lebihan/dev/Java/garmin/target/classes:/home/lebihan/.m2/repository/org/slf4j/slf4j-api/1.7.33/slf4j-api-1.7.33.jar:/home/lebihan/.m2/repository/org/slf4j/log4j-over-slf4j/1.7.33/log4j-over-slf4j-1.7.33.jar:/home/lebihan/.m2/repository/ch/qos/logback/logback-classic/1.2.10/logback-classic-1.2.10.jar:/home/lebihan/.m2/repository/ch/qos/logback/logback-core/1.2.10/logback-core-1.2.10.jar:/home/lebihan/.m2/repository/org/springframework/boot/spring-boot-starter-web/2.6.3/spring-boot-starter-web-2.6.3.jar:/home/lebihan/.m2/repository/org/springframework/boot/spring-boot-starter/2.6.3/spring-boot-starter-2.6.3.jar:/home/lebihan/.m2/repository/org/springframework/boot/spring-boot/2.6.3/spring-boot-2.6.3.jar:/home/lebihan/.m2/repository/org/springframework/boot/spring-boot-autoconfigure/2.6.3/spring-boot-autoconfigure-2.6.3.jar:/home/lebihan/.m2/repository/org/springframework/boot/spring-boot-starter-logging/2.6.3/spring-boot-starter-logging-2.6.3.jar:/home/lebihan/.m2/repository/org/apache/logging/log4j/log4j-to-slf4j/2.17.1/log4j-to-slf4j-2.17.1.jar:/home/lebihan/.m2/repository/org/apache/logging/log4j/log4j-api/2.17.1/log4j-api-2.17.1.jar:/home/lebihan/.m2/repository/org/slf4j/jul-to-slf4j/1.7.33/jul-to-slf4j-1.7.33.jar:/home/lebihan/.m2/repository/jakarta/annotation/jakarta.annotation-api/1.3.5/jakarta.annotation-api-1.3.5.jar:/home/lebihan/.m2/repository/org/yaml/snakeyaml/1.29/snakeyaml-1.29.jar:/home/lebihan/.m2/repository/org/springframework/boot/spring-boot-starter-json/2.6.3/spring-boot-starter-json-2.6.3.jar:/home/lebihan/.m2/repository/com/fasterxml/jackson/datatype/jackson-datatype-jdk8/2.13.1/jackson-datatype-jdk8-2.13.1.jar:/home/lebihan/.m2/repository/com/fasterxml/jackson/datatype/jackson-datatype-jsr310/2.13.1/jackson-datatype-jsr310-2.13.1.jar:/home/lebihan/.m2/repository/com/fasterxml/jackson/module/jackson-module-parameter-names/2.13.1/jackson-module-parameter-names-2.13.1.jar:/home/lebihan/.m2/repository/org/springframework/boot/spring-boot-starter-tomcat/2.6.3/spring-boot-starter-tomcat-2.6.3.jar:/home/lebihan/.m2/repository/org/apache/tomcat/embed/tomcat-embed-core/9.0.56/tomcat-embed-core-9.0.56.jar:/home/lebihan/.m2/repository/org/apache/tomcat/embed/tomcat-embed-el/9.0.56/tomcat-embed-el-9.0.56.jar:/home/lebihan/.m2/repository/org/apache/tomcat/embed/tomcat-embed-websocket/9.0.56/tomcat-embed-websocket-9.0.56.jar:/home/lebihan/.m2/repository/org/springframework/spring-web/5.3.15/spring-web-5.3.15.jar:/home/lebihan/.m2/repository/org/springframework/spring-beans/5.3.15/spring-beans-5.3.15.jar:/home/lebihan/.m2/repository/org/springframework/spring-webmvc/5.3.15/spring-webmvc-5.3.15.jar:/home/lebihan/.m2/repository/org/springframework/spring-aop/5.3.15/spring-aop-5.3.15.jar:/home/lebihan/.m2/repository/org/springframework/spring-context/5.3.15/spring-context-5.3.15.jar:/home/lebihan/.m2/repository/org/springframework/spring-expression/5.3.15/spring-expression-5.3.15.jar:/home/lebihan/.m2/repository/org/springframework/spring-core/5.3.15/spring-core-5.3.15.jar:/home/lebihan/.m2/repository/org/springframework/spring-jcl/5.3.15/spring-jcl-5.3.15.jar:/home/lebihan/.m2/repository/org/apache/kafka/kafka-streams/3.1.0/kafka-streams-3.1.0.jar:/home/lebihan/.m2/repository/org/apache/kafka/kafka-clients/3.0.0/kafka-clients-3.0.0.jar:/home/lebihan/.m2/repository/com/github/luben/zstd-jni/1.5.0-2/zstd-jni-1.5.0-2.jar:/home/lebihan/.m2/repository/org/lz4/lz4-java/1.7.1/lz4-java-1.7.1.jar:/home/lebihan/.m2/repository/org/xerial/snappy/snappy-java/1.1.8.1/snappy-java-1.1.8.1.jar:/home/lebihan/.m2/repository/org/rocksdb/rocksdbjni/6.22.1.1/rocksdbjni-6.22.1.1.jar:/home/lebihan/.m2/repository/com/fasterxml/jackson/core/jackson-annotations/2.13.1/jackson-annotations-2.13.1.jar:/home/lebihan/.m2/repository/com/fasterxml/jackson/core/jackson-databind/2.13.1/jackson-databind-2.13.1.jar:/home/lebihan/.m2/repository/com/fasterxml/jackson/core/jackson-core/2.13.1/jackson-core-2.13.1.jar extracteur.garmin.Kafka
07:57:49.720 [main] INFO extracteur.garmin.Kafka - L'extracteur de données Garmin démarre...
07:57:49.747 [main] INFO o.a.k.streams.StreamsConfig - StreamsConfig values: 
    acceptable.recovery.lag = 10000
    application.id = dev1
    application.server = 
    bootstrap.servers = [localhost:9092]
    buffered.records.per.partition = 1000
    built.in.metrics.version = latest
    cache.max.bytes.buffering = 10485760
    client.id = 
    commit.interval.ms = 30000
    connections.max.idle.ms = 540000
    default.deserialization.exception.handler = class o.a.k.streams.errors.LogAndFailExceptionHandler
    default.key.serde = class o.a.k.common.serialization.Serdes$VoidSerde
    default.list.key.serde.inner = null
    default.list.key.serde.type = null
    default.list.value.serde.inner = null
    default.list.value.serde.type = null
    default.production.exception.handler = class o.a.k.streams.errors.DefaultProductionExceptionHandler
    default.timestamp.extractor = class o.a.k.streams.processor.FailOnInvalidTimestamp
    default.value.serde = class o.a.k.common.serialization.Serdes$StringSerde
    max.task.idle.ms = 0
    max.warmup.replicas = 2
    metadata.max.age.ms = 300000
    metric.reporters = []
    metrics.num.samples = 2
    metrics.recording.level = INFO
    metrics.sample.window.ms = 30000
    num.standby.replicas = 0
    num.stream.threads = 1
    poll.ms = 100
    probing.rebalance.interval.ms = 600000
    processing.guarantee = at_least_once
    receive.buffer.bytes = 32768
    reconnect.backoff.max.ms = 1000
    reconnect.backoff.ms = 50
    replication.factor = -1
    request.timeout.ms = 40000
    retries = 0
    retry.backoff.ms = 100
    rocksdb.config.setter = null
    security.protocol = PLAINTEXT
    send.buffer.bytes = 131072
    state.cleanup.delay.ms = 600000
    state.dir = /tmp/kafka-streams
    task.timeout.ms = 300000
    topology.optimization = none
    upgrade.from = null
    window.size.ms = null
    windowed.inner.class.serde = null
    windowstore.changelog.additional.retention.ms = 86400000

07:57:49.760 [main] INFO o.a.k.clients.admin.AdminClientConfig - AdminClientConfig values: 
    bootstrap.servers = [localhost:9092]
    client.dns.lookup = use_all_dns_ips
    client.id = admin
    connections.max.idle.ms = 300000
    default.api.timeout.ms = 60000
    metadata.max.age.ms = 300000
    metric.reporters = []
    metrics.num.samples = 2
    metrics.recording.level = INFO
    metrics.sample.window.ms = 30000
    receive.buffer.bytes = 65536
    reconnect.backoff.max.ms = 1000
    reconnect.backoff.ms = 50
    request.timeout.ms = 30000
    retries = 2147483647
    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
    security.providers = null
    send.buffer.bytes = 131072
    socket.connection.setup.timeout.max.ms = 30000
    socket.connection.setup.timeout.ms = 10000
    ssl.cipher.suites = null
    ssl.enabled.protocols = [TLSv1.2, TLSv1.3]
    ssl.endpoint.identification.algorithm = https
    ssl.engine.factory.class = null
    ssl.key.password = null
    ssl.keymanager.algorithm = SunX509
    ssl.keystore.certificate.chain = null
    ssl.keystore.key = null
    ssl.keystore.location = null
    ssl.keystore.password = null
    ssl.keystore.type = JKS
    ssl.protocol = TLSv1.3
    ssl.provider = null
    ssl.secure.random.implementation = null
    ssl.trustmanager.algorithm = PKIX
    ssl.truststore.certificates = null
    ssl.truststore.location = null
    ssl.truststore.password = null
    ssl.truststore.type = JKS

07:57:49.790 [main] INFO o.a.k.common.utils.AppInfoParser - Kafka version: 3.0.0
07:57:49.790 [main] INFO o.a.k.common.utils.AppInfoParser - Kafka commitId: 8cb0a5e9d3441962
07:57:49.790 [main] INFO o.a.k.common.utils.AppInfoParser - Kafka startTimeMs: 1644908269788
07:57:49.793 [main] INFO o.a.k.streams.KafkaStreams - stream-client [dev1-d1c8ce47-6fbf-41b7-b8aa-e3d094703088] Kafka Streams version: 3.1.0
07:57:49.793 [main] INFO o.a.k.streams.KafkaStreams - stream-client [dev1-d1c8ce47-6fbf-41b7-b8aa-e3d094703088] Kafka Streams commit ID: 37edeed0777bacb3
07:57:49.800 [main] INFO o.a.k.streams.processor.internals.StreamThread - stream-thread [StreamThread-1] Creating restore consumer client
07:57:49.802 [main] INFO o.a.k.clients.consumer.ConsumerConfig - ConsumerConfig values: 
    allow.auto.create.topics = true
    auto.commit.interval.ms = 5000
    auto.offset.reset = none
    bootstrap.servers = [localhost:9092]
    check.crcs = true
    client.dns.lookup = use_all_dns_ips
    client.id = StreamThread-1-restore-consumer
    client.rack = 
    connections.max.idle.ms = 540000
    default.api.timeout.ms = 60000
    enable.auto.commit = false
    exclude.internal.topics = true
    fetch.max.bytes = 52428800
    fetch.max.wait.ms = 500
    fetch.min.bytes = 1
    group.id = null
    group.instance.id = null
    heartbeat.interval.ms = 3000
    interceptor.classes = []
    internal.leave.group.on.close = false
    internal.throw.on.fetch.stable.offset.unsupported = false
    isolation.level = read_uncommitted
    key.deserializer = class o.a.k.common.serialization.ByteArrayDeserializer
    max.partition.fetch.bytes = 1048576
    max.poll.interval.ms = 300000
    max.poll.records = 1000
    metadata.max.age.ms = 300000
    metric.reporters = []
    metrics.num.samples = 2
    metrics.recording.level = INFO
    metrics.sample.window.ms = 30000
    partition.assignment.strategy = [class o.a.k.clients.consumer.RangeAssignor, class o.a.k.clients.consumer.CooperativeStickyAssignor]
    receive.buffer.bytes = 65536
    reconnect.backoff.max.ms = 1000
    reconnect.backoff.ms = 50
    request.timeout.ms = 30000
    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
    security.providers = null
    send.buffer.bytes = 131072
    session.timeout.ms = 45000
    socket.connection.setup.timeout.max.ms = 30000
    socket.connection.setup.timeout.ms = 10000
    ssl.cipher.suites = null
    ssl.enabled.protocols = [TLSv1.2, TLSv1.3]
    ssl.endpoint.identification.algorithm = https
    ssl.engine.factory.class = null
    ssl.key.password = null
    ssl.keymanager.algorithm = SunX509
    ssl.keystore.certificate.chain = null
    ssl.keystore.key = null
    ssl.keystore.location = null
    ssl.keystore.password = null
    ssl.keystore.type = JKS
    ssl.protocol = TLSv1.3
    ssl.provider = null
    ssl.secure.random.implementation = null
    ssl.trustmanager.algorithm = PKIX
    ssl.truststore.certificates = null
    ssl.truststore.location = null
    ssl.truststore.password = null
    ssl.truststore.type = JKS
    value.deserializer = class o.a.k.common.serialization.ByteArrayDeserializer

07:57:49.816 [main] INFO o.a.k.common.utils.AppInfoParser - Kafka version: 3.0.0
07:57:49.816 [main] INFO o.a.k.common.utils.AppInfoParser - Kafka commitId: 8cb0a5e9d3441962
07:57:49.816 [main] INFO o.a.k.common.utils.AppInfoParser - Kafka startTimeMs: 1644908269816
07:57:49.818 [main] INFO o.a.k.streams.processor.internals.StreamThread - stream-thread [StreamThread-1] Creating thread producer client
07:57:49.820 [main] INFO o.a.k.clients.producer.ProducerConfig - ProducerConfig values: 
    acks = -1
    batch.size = 16384
    bootstrap.servers = [localhost:9092]
    buffer.memory = 33554432
    client.dns.lookup = use_all_dns_ips
    client.id = StreamThread-1-producer
    compression.type = none
    connections.max.idle.ms = 540000
    delivery.timeout.ms = 120000
    enable.idempotence = true
    interceptor.classes = []
    key.serializer = class o.a.k.common.serialization.ByteArraySerializer
    linger.ms = 100
    max.block.ms = 60000
    max.in.flight.requests.per.connection = 5
    max.request.size = 1048576
    metadata.max.age.ms = 300000
    metadata.max.idle.ms = 300000
    metric.reporters = []
    metrics.num.samples = 2
    metrics.recording.level = INFO
    metrics.sample.window.ms = 30000
    partitioner.class = class o.a.k.clients.producer.internals.DefaultPartitioner
    receive.buffer.bytes = 32768
    reconnect.backoff.max.ms = 1000
    reconnect.backoff.ms = 50
    request.timeout.ms = 30000
    retries = 2147483647
    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
    security.providers = null
    send.buffer.bytes = 131072
    socket.connection.setup.timeout.max.ms = 30000
    socket.connection.setup.timeout.ms = 10000
    ssl.cipher.suites = null
    ssl.enabled.protocols = [TLSv1.2, TLSv1.3]
    ssl.endpoint.identification.algorithm = https
    ssl.engine.factory.class = null
    ssl.key.password = null
    ssl.keymanager.algorithm = SunX509
    ssl.keystore.certificate.chain = null
    ssl.keystore.key = null
    ssl.keystore.location = null
    ssl.keystore.password = null
    ssl.keystore.type = JKS
    ssl.protocol = TLSv1.3
    ssl.provider = null
    ssl.secure.random.implementation = null
    ssl.trustmanager.algorithm = PKIX
    ssl.truststore.certificates = null
    ssl.truststore.location = null
    ssl.truststore.password = null
    ssl.truststore.type = JKS
    transaction.timeout.ms = 60000
    transactional.id = null
    value.serializer = class o.a.k.common.serialization.ByteArraySerializer

07:57:49.828 [main] INFO o.a.k.common.utils.AppInfoParser - Kafka version: 3.0.0
07:57:49.828 [main] INFO o.a.k.common.utils.AppInfoParser - Kafka commitId: 8cb0a5e9d3441962
07:57:49.828 [main] INFO o.a.k.common.utils.AppInfoParser - Kafka startTimeMs: 1644908269828
07:57:49.830 [main] INFO o.a.k.streams.processor.internals.StreamThread - stream-thread [StreamThread-1] Creating consumer client
07:57:49.831 [main] INFO o.a.k.clients.consumer.ConsumerConfig - ConsumerConfig values: 
    allow.auto.create.topics = false
    auto.commit.interval.ms = 5000
    auto.offset.reset = earliest
    bootstrap.servers = [localhost:9092]
    check.crcs = true
    client.dns.lookup = use_all_dns_ips
    client.id = StreamThread-1-consumer
    client.rack = 
    connections.max.idle.ms = 540000
    default.api.timeout.ms = 60000
    enable.auto.commit = false
    exclude.internal.topics = true
    fetch.max.bytes = 52428800
    fetch.max.wait.ms = 500
    fetch.min.bytes = 1
    group.id = dev1
    group.instance.id = null
    heartbeat.interval.ms = 3000
    interceptor.classes = []
    internal.leave.group.on.close = false
    internal.throw.on.fetch.stable.offset.unsupported = false
    isolation.level = read_uncommitted
    key.deserializer = class o.a.k.common.serialization.ByteArrayDeserializer
    max.partition.fetch.bytes = 1048576
    max.poll.interval.ms = 300000
    max.poll.records = 1000
    metadata.max.age.ms = 300000
    metric.reporters = []
    metrics.num.samples = 2
    metrics.recording.level = INFO
    metrics.sample.window.ms = 30000
    partition.assignment.strategy = [o.a.k.streams.processor.internals.StreamsPartitionAssignor]
    receive.buffer.bytes = 65536
    reconnect.backoff.max.ms = 1000
    reconnect.backoff.ms = 50
    request.timeout.ms = 30000
    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
    security.providers = null
    send.buffer.bytes = 131072
    session.timeout.ms = 45000
    socket.connection.setup.timeout.max.ms = 30000
    socket.connection.setup.timeout.ms = 10000
    ssl.cipher.suites = null
    ssl.enabled.protocols = [TLSv1.2, TLSv1.3]
    ssl.endpoint.identification.algorithm = https
    ssl.engine.factory.class = null
    ssl.key.password = null
    ssl.keymanager.algorithm = SunX509
    ssl.keystore.certificate.chain = null
    ssl.keystore.key = null
    ssl.keystore.location = null
    ssl.keystore.password = null
    ssl.keystore.type = JKS
    ssl.protocol = TLSv1.3
    ssl.provider = null
    ssl.secure.random.implementation = null
    ssl.trustmanager.algorithm = PKIX
    ssl.truststore.certificates = null
    ssl.truststore.location = null
    ssl.truststore.password = null
    ssl.truststore.type = JKS
    value.deserializer = class o.a.k.common.serialization.ByteArrayDeserializer

    replication.factor = -1
    windowstore.changelog.additional.retention.ms = 86400000
07:57:49.836 [main] INFO o.a.k.streams.processor.internals.assignment.AssignorConfiguration - stream-thread [StreamThread-1-consumer] Cooperative rebalancing protocol is enabled now
07:57:49.840 [main] INFO o.a.k.common.utils.AppInfoParser - Kafka version: 3.0.0
07:57:49.840 [main] INFO o.a.k.common.utils.AppInfoParser - Kafka commitId: 8cb0a5e9d3441962
07:57:49.840 [main] INFO o.a.k.common.utils.AppInfoParser - Kafka startTimeMs: 1644908269840
07:57:49.844 [main] INFO o.a.k.streams.KafkaStreams - stream-client [dev1-d1c8ce47-6fbf-41b7-b8aa-e3d094703088] State transition from CREATED to REBALANCING
07:57:49.845 [StreamThread-1] INFO o.a.k.streams.processor.internals.StreamThread - stream-thread [StreamThread-1] Starting
07:57:49.845 [StreamThread-1] INFO o.a.k.streams.processor.internals.StreamThread - stream-thread [StreamThread-1] State transition from CREATED to STARTING
07:57:49.845 [StreamThread-1] INFO o.a.k.clients.consumer.KafkaConsumer - [Consumer clientId=StreamThread-1-consumer, groupId=dev1] Subscribed to topic(s): poids_garmin_brut
07:57:49.845 [main] INFO o.a.k.streams.KafkaStreams - stream-client [dev1-d1c8ce47-6fbf-41b7-b8aa-e3d094703088] State transition from REBALANCING to PENDING_SHUTDOWN
07:57:49.846 [kafka-streams-close-thread] INFO o.a.k.streams.processor.internals.StreamThread - stream-thread [StreamThread-1] Informed to shut down
07:57:49.846 [kafka-streams-close-thread] INFO o.a.k.streams.processor.internals.StreamThread - stream-thread [StreamThread-1] State transition from STARTING to PENDING_SHUTDOWN
07:57:49.919 [kafka-producer-network-thread | StreamThread-1-producer] INFO o.a.k.clients.Metadata - [Producer clientId=StreamThread-1-producer] Cluster ID: QKJGs4glRAy7besZxXNCrg
07:57:49.920 [StreamThread-1] INFO o.a.k.clients.Metadata - [Consumer clientId=StreamThread-1-consumer, groupId=dev1] Cluster ID: QKJGs4glRAy7besZxXNCrg
07:57:49.921 [StreamThread-1] INFO o.a.k.clients.consumer.internals.ConsumerCoordinator - [Consumer clientId=StreamThread-1-consumer, groupId=dev1] Discovered group coordinator debian:9092 (id: 2147483647 rack: null)
07:57:49.922 [StreamThread-1] INFO o.a.k.clients.consumer.internals.ConsumerCoordinator - [Consumer clientId=StreamThread-1-consumer, groupId=dev1] (Re-)joining group
07:57:49.929 [StreamThread-1] INFO o.a.k.clients.consumer.internals.ConsumerCoordinator - [Consumer clientId=StreamThread-1-consumer, groupId=dev1] Request joining group due to: need to re-join with the given member-id
07:57:49.929 [StreamThread-1] INFO o.a.k.clients.consumer.internals.ConsumerCoordinator - [Consumer clientId=StreamThread-1-consumer, groupId=dev1] (Re-)joining group
07:57:49.930 [StreamThread-1] INFO o.a.k.clients.consumer.internals.ConsumerCoordinator - [Consumer clientId=StreamThread-1-consumer, groupId=dev1] Successfully joined group with generation Generation{generationId=3, memberId='StreamThread-1-consumer-34c0df37-baeb-4582-bdfe-79ab9e2e410c', protocol='stream'}
07:57:49.936 [StreamThread-1] INFO o.a.k.streams.processor.internals.StreamsPartitionAssignor - stream-thread [StreamThread-1-consumer] All members participating in this rebalance: 
d1c8ce47-6fbf-41b7-b8aa-e3d094703088: [StreamThread-1-consumer-34c0df37-baeb-4582-bdfe-79ab9e2e410c].
07:57:49.938 [StreamThread-1] INFO o.a.k.streams.processor.internals.assignment.HighAvailabilityTaskAssignor - Decided on assignment: {d1c8ce47-6fbf-41b7-b8aa-e3d094703088=[activeTasks: ([0_0]) standbyTasks: ([]) prevActiveTasks: ([]) prevStandbyTasks: ([]) changelogOffsetTotalsByTask: ([]) taskLagTotals: ([]) capacity: 1 assigned: 1]} with no followup probing rebalance.
07:57:49.938 [StreamThread-1] INFO o.a.k.streams.processor.internals.StreamsPartitionAssignor - stream-thread [StreamThread-1-consumer] Assigned tasks [0_0] including stateful [] to clients as: 
d1c8ce47-6fbf-41b7-b8aa-e3d094703088=[activeTasks: ([0_0]) standbyTasks: ([])].
07:57:49.939 [StreamThread-1] INFO o.a.k.streams.processor.internals.StreamsPartitionAssignor - stream-thread [StreamThread-1-consumer] Client d1c8ce47-6fbf-41b7-b8aa-e3d094703088 per-consumer assignment:
    prev owned active {}
    prev owned standby {StreamThread-1-consumer-34c0df37-baeb-4582-bdfe-79ab9e2e410c=[]}
    assigned active {StreamThread-1-consumer-34c0df37-baeb-4582-bdfe-79ab9e2e410c=[0_0]}
    revoking active {}
    assigned standby {}

07:57:49.939 [StreamThread-1] INFO o.a.k.streams.processor.internals.StreamsPartitionAssignor - stream-thread [StreamThread-1-consumer] Finished stable assignment of tasks, no followup rebalances required.
07:57:49.939 [StreamThread-1] INFO o.a.k.clients.consumer.internals.ConsumerCoordinator - [Consumer clientId=StreamThread-1-consumer, groupId=dev1] Finished assignment for group at generation 3: {StreamThread-1-consumer-34c0df37-baeb-4582-bdfe-79ab9e2e410c=Assignment(partitions=[poids_garmin_brut-0], userDataSize=52)}
07:57:49.943 [StreamThread-1] INFO o.a.k.clients.consumer.internals.ConsumerCoordinator - [Consumer clientId=StreamThread-1-consumer, groupId=dev1] Successfully synced group in generation Generation{generationId=3, memberId='StreamThread-1-consumer-34c0df37-baeb-4582-bdfe-79ab9e2e410c', protocol='stream'}
07:57:49.943 [StreamThread-1] INFO o.a.k.clients.consumer.internals.ConsumerCoordinator - [Consumer clientId=StreamThread-1-consumer, groupId=dev1] Updating assignment with
    Assigned partitions:                       [poids_garmin_brut-0]
    Current owned partitions:                  []
    Added partitions (assigned - owned):       [poids_garmin_brut-0]
    Revoked partitions (owned - assigned):     []

07:57:49.943 [StreamThread-1] INFO o.a.k.clients.consumer.internals.ConsumerCoordinator - [Consumer clientId=StreamThread-1-consumer, groupId=dev1] Notifying assignor about the new Assignment(partitions=[poids_garmin_brut-0], userDataSize=52)
07:57:49.944 [StreamThread-1] INFO o.a.k.streams.processor.internals.StreamsPartitionAssignor - stream-thread [StreamThread-1-consumer] No followup rebalance was requested, resetting the rebalance schedule.
07:57:49.944 [StreamThread-1] INFO o.a.k.streams.processor.internals.TaskManager - stream-thread [StreamThread-1] Handle new assignment with:
    New active tasks: [0_0]
    New standby tasks: []
    Existing active tasks: []
    Existing standby tasks: []
07:57:49.950 [StreamThread-1] INFO o.a.k.clients.consumer.internals.ConsumerCoordinator - [Consumer clientId=StreamThread-1-consumer, groupId=dev1] Adding newly assigned partitions: poids_garmin_brut-0
07:57:49.953 [StreamThread-1] INFO o.a.k.clients.consumer.internals.ConsumerCoordinator - [Consumer clientId=StreamThread-1-consumer, groupId=dev1] Found no committed offset for partition poids_garmin_brut-0
07:57:49.954 [StreamThread-1] INFO o.a.k.streams.processor.internals.StreamThread - stream-thread [StreamThread-1] Shutting down
[...]

Process finished with exit code 0

What am I doing wrong?


  • I’m running my Kafka instance and its Java program locally, on the same PC.

  • I’ve experienced 3.1.0 and 2.8.1 versions of Kafka, or removed any traces of Spring in the Java program without success.

I belive I’m facing a configuration problem.

Answer

I fear having shamefully found the cause of my trouble :

streams.start();
streams.close();

The streams.start() starts the listening of the stream.
But the steams.close() ends it immediately and close the program a second after!

And what I saw, commenting that streams.close() statement, is that the first message from poids_garmin_brut topic takes around 20 seconds to be detected and displayed, provided new messages are injected in the topic, then others new injected ones comes instantaneously.

I believed that the property

config.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");

had for goal to ask Kafka to read a topic from its beginning, but it’s not the case.