I created an application which use Kafka. So how can I find how many MB/sec my consumers reads ?
My topics have only one partition
Are you using the Java Kafka consumer API? If yes, some JMX metrics are exposed by it and some more specific to consumer fetching. You can see them here:
https://kafka.apache.org/documentation/#consumer_fetch_monitoring
Related
I run a system comprising an InfluxDB, a Kafka Broker and data sources (sensors) producing time series data. The purpose of the broker is to protect the database from inbound event overload and as a format-agnostic platform for ingesting data. The data is transferred from Kafka to InfluxDB via Apache Camel routes.
I would like to use Kafka a intermediate message buffer in case a Camel route crashes or becomes unavailable - which is the most often error in the system. Up to now, I didn’t achieve to configure Kafka in a manner that inbound messages remain available for later consumption.
How do I configure it properly?
The messages will retain in Kafka topics based on its retention policies (you can choose between time or byte size limits) as described in the Topic Configurations. With
cleanup.policy=delete
Retention.ms=-1
the messages will in a Kafka topic will never be deleted.
Then your camel consumer will be able to re-read all messages (offsets) if you select a new consumer group or reset the offsets of the existing consumer group. Otherwise, your camel consumer might auto commit the messages (check corresponding consumer configuration) and it will not be possible to re-read offsets again for the same consumer group.
To limit the consumption rate of the camel consumer you may adjust configurations like maxPollRecords or fetchMaxBytes which are described in the docs.
How to list producers writing to a certain kafka topic using kafka CLI ?
There is no command line tool available that is able to list all producers for a certain topic.
This would require that in Kafka there is a central place where all producers and their metadata are being stored which is not the case (as opposed to consumers and their ConsumerGroups).
I am new to Kafka Streams.
I would like to connect to Kafka Cluster and read all Stream Topologies.
Is there an API that would allow doing that?
I am looking at the Topology class, is there a way to list all Topologies?
https://docs.confluent.io/5.5.0/streams/javadocs/index.html
That is not possible. Brokers don't know anything about Kafka Streams applications.
I have Nifi cluster of and Kafka is also installed there.
Created one topic with 5 partitions, start consuming that topic with one gourp-id. So that each partition will get unique messages.
Now I created the 5 ConsumeKafka_1_0 processors having the intent of getting unique messages on each consumer side. But only 2 of the ConsumeKafka_1_0 are consuming all the messages rest is setting ideal.
Now what I did is started the 5 command line Kafka consumer, and what happened is, I was able to see the all the partitions are getting the messages and able to consume them from command line consumer in round-robin fashion only.
Also, I tried descried the Kafka group and what I saw was only 2 of the Nifi ConsumeKafka_1_0 is consuming all the 5 partitions and rest is ideal, see the snapshot.
Would you please let me what I am doing wrong here with Nifi consumer processor.
Note - i used Nifi version is 1.5 and Kafka version is 1.0.
I've written this article which explains how the integration with Kafka works:
https://bryanbende.com/development/2016/09/15/apache-nifi-and-apache-kafka
The Apache Kafka client (used by NiFi) is what assigns partitions to the consumers.
Typically if you had a 5 node NiFi cluster, with 1 ConsumeKafka processor on the canvas with 1 concurrent task, then each node would be consuming 1 partition.
I'm a new user of Apache Kafka and I'm still getting to know the internals.
In my use case, I need to increase the number of partitions of a topic dynamically from the Kafka Producer client.
I found other similar questions regarding increasing the partition size, but they utilize the zookeeper configuration. But my kafkaProducer has only the Kafka broker config, but not the zookeeper config.
Is there any way I can increase the number of partitions of a topic from the Producer side? I'm running Kafka version 0.10.0.0.
As of Kafka 0.10.0.1 (latest release): As Manav said it is not possible to increase the number of partitions from the Producer client.
Looking ahead (next releases): In an upcoming version of Kafka, clients will be able to perform some topic management actions, as outlined in KIP-4. A lot of the KIP-4 functionality is already completed and available in Kafka's trunk; the code in trunk as of today allows client to create and to delete topics. But unfortunately, for your use case, increasing the number of partitions is still not possible yet -- this is in scope for KIP-4 (see Alter Topics Request) but is not completed yet.
TL;DR: The next versions of Kafka will allow you to increase the number of partitions of a Kafka topic, but this functionality is not yet available.
It is not possible to increase the number of partitions from the Producer client.
Any specific use case use why you cannot use the broker to achieve this ?
But my kafkaProducer has only the Kafka broker config, but not the
zookeeper config.
I don't think any client will let you change the broker config. You can only access (read) the server side config at max.
Your producer can provide different keys for ProducerRecord's. The broker would place them in different partitions. For example, if you need two partitions, use keys "abc" and "xyz".
This can be done in version 0.9 as well.