I use kafka which version is kafka V0.11.
I have a consumer group which group.id = test, but when I use command like kafka-consumer-groups --bootstrap-server localhost:9092 --group test --describe, I find no consumer under this group.
however, service consume is normal.
Who could know why? thx.
Related
I am using kafka-python and I want to consume messages from a topic. For monitoring reasons, I want to create a consumer and assign it to a consumer'group.
I am using the following functions:
server = KafkaConsumer(application.name, bootstrap_servers = str(ip_address)+':'+str(ip_port) , client_id =str(application.name)+'_dispatcher', group_id='xxxxxx')
server.subscribe(topics=[application.name])
However, when monitoring the consumer groups using:
bash kafka-consumer-groups.sh --bootstrap-server localhost:9092 --describe --all-groups
I still see that the consumer is not added to the consumer groups and the consumer group is not rebalancing. Could someone explain to me what is the problem with Kafka?
I have several consumers that connect to Kafka Cluster that I do not have control over. At the same time, I would like to have visibility into how those consumers are configured.
Is there an API to list all consumers (if there is one for publishers, it is an added benefit) and then read all their configs?
I am talking about these consumer settings:
https://docs.confluent.io/current/installation/configuration/consumer-configs.html#cp-config-consumer
This is not possible as most of those settings are configured at the consumer only and are not pushed to the brokers or any topic.
It's possible however to get a high-level description for a given consumer group:
./kafka-consumer-groups.sh --bootstrap-server localhost:9092 --describe --group consumer-group
I am running kafka locally following instructions on quick start guide here,
and then I defined my consumer group configuration in config/consumer.properties so that my consumer can pick messages from the defined group.id
Running the following command,
bin/kafka-consumer-groups.sh --list --bootstrap-server localhost:9092
results in,
test-consumer-group <-- group.id defined in conf/consumer.properties
console-consumer-67807 <-- when connecting to kafka via kafka-console-consumer.sh
I am able to connect to kafka via a python based consumer that is configured to use the provide group.id i.e test-consumer-group
First of all, I am not able to understand how/when kafka creates consumer groups. It seems it loads the conf/consumer.properties at some point of time and additionally it implicitly creates consumer-group (in my case console-consumer-67807) when connecting via kafka-console-consumer.sh.
How can I explicitly create my own consumer group, lets say my-created-consumer-group ?
You do not explicitly create consumer groups but rather build consumers which always belong to a consumer group. No matter which technology (Spark, Spring, Flink, ...) you are using, each Kafka Consumer will have a Consumer Group. The consumer group is configurable for each individual consumer.
It seems it loads the conf/consumer.properties at some point of time and additionally it implicitly creates consumer-group (in my case console-consumer-67807) when connecting via kafka-console-consumer.sh
If you do not tell your console consumer to actually make use of that file it will not be taken into consideration.
There are the following alternatives to provide the name of a consumer group:
Console Consumer with property file (--consumer.config)
This is how the file config/consumer.properties should look like
# consumer group id
group.id=my-created-consumer-group
And this is how you would then ensure that the console-consumer takes this group.id into consideration:
bin/kafka-console-consumer.sh --bootstrap-server localhost:9092 --topic test-topic --from-beginning --consumer.config /path/to/config/consumer.properties
Console consumer with --group
For console consumers the consumer group gets created automatically with prefix "console-consumer" and suffix something like a PID, unless you provide your own consumer group by adding --group:
bin/kafka-console-consumer.sh --bootstrap-server localhost:9092 --topic test-topic --from-beginning --group my-created-consumer-group
Standard code-based consumer API
When using the standard JAVA/Scala/... Consumer API you could provide the Consumer Group through the properties:
Properties settings = new Properties();
settings.put(ConsumerConfig.GROUP_ID_CONFIG, "basic-consumer");
// set more properties
KafkaConsumer<String, String> consumer = new KafkaConsumer<>(settings)) {
consumer.subscribe(Arrays.asList("test-topic")
I want to check the lag for a consumer group which was assigned manually to particular topic , is this possible ? . I am using Kafka - 0.10.0.1 .I used sh kafka-run-class.sh kafka.admin.ConsumerGroupCommand —new-consumer —describe —bootstrap-server localhost:9092 —group test but it says no group exists , so i wonder when we assign a partition manually can we check the lag for the consumer.
In Nussknacker we are using AKHQ GUI tool which provides various monitoring options as consumer and consumer groups lag and general Kafka operations as topic, topic data and schema registry management
./kafka-consumer-groups.sh --bootstrap-server localhost:9092
--describe --group
.
If You want API support or visual lag monitoring you can use https://github.com/yahoo/kafka-manager
I am playing aroung Kafka, when I use
bin/kafka-console-consumer.sh --zookeeper localhost:2181 --from-beginning --topic test
Kafka will automatically create a consumer group. I am wondering how to get the consumer group name?
You should use kafka-consumer-groups.sh. The following command will list you all consumer groups.
bin/kafka-consumer-groups.sh --list --bootstrap-server localhost:9092
Note: This will only show information about consumers that use the Java Consumer API (non-Zookeeper-based consumers).