[apache-kafka] Purge Kafka Topic

Is there a way to purge the topic in kafka?

I pushed a message that was too big into a kafka message topic on my local machine, now I'm getting an error:

kafka.common.InvalidMessageSizeException: invalid message size

Increasing the fetch.size is not ideal here, because I don't actually want to accept messages that big.

UPDATE: This answer is relevant for Kafka 0.6. For Kafka 0.8 and later see answer by @Patrick.

Yes, stop kafka and manually delete all files from corresponding subdirectory (it's easy to find it in kafka data directory). After kafka restart the topic will be empty.

A lot of great answers over here but among them, I didn't find one about docker. I spent some time to figure out that using the broker container is wrong for this case (obviously!!!)

## this is wrong!
docker exec broker1 kafka-topics --zookeeper localhost:2181 --alter --topic mytopic --config retention.ms=1000

Exception in thread "main" kafka.zookeeper.ZooKeeperClientTimeoutException: Timed out waiting for connection while in state: CONNECTING
        at kafka.zookeeper.ZooKeeperClient.$anonfun$waitUntilConnected$3(ZooKeeperClient.scala:258)
        at scala.runtime.java8.JFunction0$mcV$sp.apply(JFunction0$mcV$sp.java:23)
        at kafka.utils.CoreUtils$.inLock(CoreUtils.scala:253)
        at kafka.zookeeper.ZooKeeperClient.waitUntilConnected(ZooKeeperClient.scala:254)
        at kafka.zookeeper.ZooKeeperClient.<init>(ZooKeeperClient.scala:112)
        at kafka.zk.KafkaZkClient$.apply(KafkaZkClient.scala:1826)
        at kafka.admin.TopicCommand$ZookeeperTopicService$.apply(TopicCommand.scala:280)
        at kafka.admin.TopicCommand$.main(TopicCommand.scala:53)
        at kafka.admin.TopicCommand.main(TopicCommand.scala)

and I should have used zookeeper:2181 instead of --zookeeper localhost:2181 as per my compose file

## this might be an option, but as per comment below not all zookeeper images can have this script included
docker exec zookeper1 kafka-topics --zookeeper localhost:2181 --alter --topic mytopic --config retention.ms=1000

the correct command would be

docker exec broker1 kafka-configs --zookeeper zookeeper:2181 --alter --entity-type topics --entity-name dev_gdn_urls --add-config retention.ms=12800000

Hope it will save someone's time.

Also, be aware that the messages won't be deleted immediately and it will happen when the segment of the log will be closed.

Tested in Kafka 0.8.2, for the quick-start example: First, Add one line to server.properties file under config folder:

delete.topic.enable=true

then, you can run this command:

bin/kafka-topics.sh --zookeeper localhost:2181 --delete --topic test

Following @steven appleyard answer I executed the following commands on Kafka 2.2.0 and they worked for me.

bin/kafka-configs.sh --zookeeper localhost:2181 --entity-type topics --entity-name <topic-name> --describe

bin/kafka-configs.sh --zookeeper localhost:2181 --entity-type topics --entity-name <topic-name> --alter --add-config retention.ms=1000

bin/kafka-configs.sh --zookeeper localhost:2181 --entity-type topics --entity-name <topic-name> --alter --delete-config retention.ms

To clean up all the messages from a particular topic using your application group (GroupName should be same as application kafka group name).

./kafka-path/bin/kafka-console-consumer.sh --zookeeper localhost:2181 --topic topicName --from-beginning --group application-group

kafka don't have direct method for purge/clean-up topic (Queues), but can do this via deleting that topic and recreate it.

first of make sure sever.properties file has and if not add delete.topic.enable=true

then, Delete topic bin/kafka-topics.sh --zookeeper localhost:2181 --delete --topic myTopic

then create it again.

bin/kafka-topics.sh --zookeeper localhost:2181 --create --topic myTopic --partitions 10 --replication-factor 2

Another, rather manual, approach for purging a topic is:

in the brokers:

1. stop kafka broker
   sudo service kafka stop
2. delete all partition log files (should be done on all brokers)
   sudo rm -R /kafka-storage/kafka-logs/<some_topic_name>-*

in zookeeper:

3. run zookeeper command line interface
   sudo /usr/lib/zookeeper/bin/zkCli.sh
4. use zkCli to remove the topic metadata
   rmr /brokers/topic/<some_topic_name>

in the brokers again:

5. restart broker service
   sudo service kafka start

have you considered having your app simply use a new renamed topic? (i.e. a topic that is named like the original topic but with a "1" appended at the end).

That would also give your app a fresh clean topic.

Here are the steps I follow to delete a topic named MyTopic:

1. Describe the topic, and take not of the broker ids
2. Stop the Apache Kafka daemon for each broker ID listed.
3. Connect to each broker, and delete the topic data folder, e.g. rm -rf /tmp/kafka-logs/MyTopic-0. Repeat for other partitions, and all replicas
4. Delete the topic metadata: zkCli.sh then rmr /brokers/MyTopic
5. Start the Apache Kafka daemon for each stopped machine

If you miss you step 3, then Apache Kafka will continue to report the topic as present (for example when if you run kafka-list-topic.sh).

Tested with Apache Kafka 0.8.0.

To purge the queue you can delete the topic:

bin/kafka-topics.sh --zookeeper localhost:2181 --delete --topic test

then re-create it:

bin/kafka-topics.sh --create --zookeeper localhost:2181 \
    --replication-factor 1 --partitions 1 --topic test

Could not add as comment because of size: Not sure if this is true, besides updating retention.ms and retention.bytes, but I noticed topic cleanup policy should be "delete" (default), if "compact", it is going to hold on to messages longer, i.e., if it is "compact", you have to specify delete.retention.ms also.

./bin/kafka-configs.sh --zookeeper localhost:2181 --describe --entity-name test-topic-3-100 --entity-type topics
Configs for topics:test-topic-3-100 are retention.ms=1000,delete.retention.ms=10000,cleanup.policy=delete,retention.bytes=1

Also had to monitor earliest/latest offsets should be same to confirm this successfully happened, can also check the du -h /tmp/kafka-logs/test-topic-3-100-*

./bin/kafka-run-class.sh kafka.tools.GetOffsetShell --broker-list "BROKER:9095" --topic test-topic-3-100 --time -1 | awk -F ":" '{sum += $3} END {print sum}' 26599762

./bin/kafka-run-class.sh kafka.tools.GetOffsetShell --broker-list "BROKER:9095" --topic test-topic-3-100 --time -2 | awk -F ":" '{sum += $3} END {print sum}' 26599762

The other problem is, you have to get current config first so you remember to revert after deletion is successful: ./bin/kafka-configs.sh --zookeeper localhost:2181 --describe --entity-name test-topic-3-100 --entity-type topics

Sometimes, if you've a saturated cluster (too many partitions, or using encrypted topic data, or using SSL, or the controller is on a bad node, or the connection is flaky, it'll take a long time to purge said topic.

I follow these steps, particularly if you're using Avro.

1: Run with kafka tools :

bash kafka-configs.sh --alter --entity-type topics --zookeeper zookeeper01.kafka.com --add-config retention.ms=1 --entity-name <topic-name>

2: Run on Schema registry node:

kafka-avro-console-consumer --consumer-property security.protocol=SSL --consumer-property ssl.truststore.location=/etc/schema-registry/secrets/trust.jks --consumer-property ssl.truststore.password=password --consumer-property ssl.keystore.location=/etc/schema-registry/secrets/identity.jks --consumer-property ssl.keystore.password=password --consumer-property ssl.key.password=password --bootstrap-server broker01.kafka.com:9092 --topic <topic-name> --new-consumer --from-beginning

3: Set topic retention back to the original setting, once topic is empty.

bash kafka-configs.sh --alter --entity-type topics --zookeeper zookeeper01.kafka.com --add-config retention.ms=604800000 --entity-name <topic-name>

Hope this helps someone, as it isn't easily advertised.

From Java, using the new AdminZkClient instead of the deprecated AdminUtils:

  public void reset() {
    try (KafkaZkClient zkClient = KafkaZkClient.apply("localhost:2181", false, 200_000,
        5000, 10, Time.SYSTEM, "metricGroup", "metricType")) {

      for (Map.Entry<String, List<PartitionInfo>> entry : listTopics().entrySet()) {
        deleteTopic(entry.getKey(), zkClient);
      }
    }
  }

  private void deleteTopic(String topic, KafkaZkClient zkClient) {

    // skip Kafka internal topic
    if (topic.startsWith("__")) {
      return;
    }

    System.out.println("Resetting Topic: " + topic);
    AdminZkClient adminZkClient = new AdminZkClient(zkClient);
    adminZkClient.deleteTopic(topic);

    // deletions are not instantaneous
    boolean success = false;
    int maxMs = 5_000;
    while (maxMs > 0 && !success) {
      try {
        maxMs -= 100;
        adminZkClient.createTopic(topic, 1, 1, new Properties(), null);
        success = true;
      } catch (TopicExistsException ignored) {
      }
    }

    if (!success) {
      Assert.fail("failed to create " + topic);
    }
  }

  private Map<String, List<PartitionInfo>> listTopics() {
    Properties props = new Properties();
    props.put("bootstrap.servers", kafkaContainer.getBootstrapServers());
    props.put("group.id", "test-container-consumer-group");
    props.put("key.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");
    props.put("value.deserializer", "org.apache.kafka.common.serialization.StringDeserializer");

    KafkaConsumer<String, String> consumer = new KafkaConsumer<>(props);
    Map<String, List<PartitionInfo>> topics = consumer.listTopics();
    consumer.close();

    return topics;
  }

Thomas' advice is great but unfortunately zkCli in old versions of Zookeeper (for example 3.3.6) do not seem to support rmr. For example compare the command line implementation in modern Zookeeper with version 3.3.

If you are faced with an old version of Zookeeper one solution is to use a client library such as zc.zk for Python. For people not familiar with Python you need to install it using pip or easy_install. Then start a Python shell (python) and you can do:

import zc.zk
zk = zc.zk.ZooKeeper('localhost:2181')
zk.delete_recursive('brokers/MyTopic') 

or even

zk.delete_recursive('brokers')

if you want to remove all the topics from Kafka.

./kafka-topics.sh --describe --zookeeper zkHost:2181 --topic myTopic

This should give retention.ms configured. Then you can use above alter command to change to 1second (and later revert back to default).

Topic:myTopic   PartitionCount:6        ReplicationFactor:1     Configs:retention.ms=86400000

While the accepted answer is correct, that method has been deprecated. Topic configuration should now be done via kafka-configs.

kafka-configs --zookeeper localhost:2181 --entity-type topics --alter --add-config retention.ms=1000 --entity-name MyTopic

Configurations set via this method can be displayed with the command

kafka-configs --zookeeper localhost:2181 --entity-type topics --describe --entity-name MyTopic

From kafka 1.1

Purge a topic

bin/kafka-configs.sh --zookeeper localhost:2181 --alter --entity-type topics --entity-name tp_binance_kline --add-config retention.ms=100

wait 1 minute, to be secure that kafka purge the topic remove the configuration, and then go to default value

bin/kafka-configs.sh --zookeeper localhost:2181 --alter --entity-type topics --entity-name tp_binance_kline --delete-config retention.ms

Following command can be used to delete all the existing messages in kafka topic:

kafka-delete-records --bootstrap-server <kafka_server:port> --offset-json-file delete.json

The structure of the delete.json file should be following:

{ "partitions": [ { "topic": "foo", "partition": 1, "offset": -1 } ], "version": 1 }

where offset :-1 will delete all the records (This command has been tested with kafka 2.0.1

The simplest approach is to set the date of the individual log files to be older than the retention period. Then the broker should clean them up and remove them for you within a few seconds. This offers several advantages:

1. No need to bring down brokers, it's a runtime operation.
2. Avoids the possibility of invalid offset exceptions (more on that below).

In my experience with Kafka 0.7.x, removing the log files and restarting the broker could lead to invalid offset exceptions for certain consumers. This would happen because the broker restarts the offsets at zero (in the absence of any existing log files), and a consumer that was previously consuming from the topic would reconnect to request a specific [once valid] offset. If this offset happens to fall outside the bounds of the new topic logs, then no harm and the consumer resumes at either the beginning or the end. But, if the offset falls within the bounds of the new topic logs, the broker attempts to fetch the message set but fails because the offset doesn't align to an actual message.

This could be mitigated by also clearing the consumer offsets in zookeeper for that topic. But if you don't need a virgin topic and just want to remove the existing contents, then simply 'touch'-ing a few topic logs is far easier and more reliable, than stopping brokers, deleting topic logs, and clearing certain zookeeper nodes.