How to expand confluent cloud kafka cluster? - apache-kafka

I have set up a confluent cloud multizone cluster and it got created with just one bootstrap server. There was no setting for choosing number of servers while creating the cluster. Even after creation, I can’t edit the number of bootstrap servers.
I want to know how to increase the number of servers in confluent cloud kafka cluster.

Under the hood, the Confluent Cloud cluster is already running multiple brokers. Depending on your cluster configuration (specifically, whether you're running Standard or Dedicated, and what region and cloud you're in), the cluster will have between six and several dozen brokers.
The way a Kafka client bootstrap server config works is that the client reaches out to the bootstrap server and requests a list of all brokers, and then uses those broker endpoints to actually produce/consume from Kafka (reference: https://jaceklaskowski.gitbooks.io/apache-kafka/content/kafka-properties-bootstrap-servers.html)
In Confluent Cloud, the provided bootstrap server is actually a load balancer in front of all of the brokers; when the client connects to the bootstrap server it'll receive the actual endpoints for all of the actual brokers, and then use that for subsequent connections.
So TL;DR, in your client, you only need to specify the one bootstrap server; under the hood, the Kafka client will connect to the (many) brokers running in Confluent Cloud, and it should all just work.
Source: I work at Confluent.

Related

Exposing Kafka brokers using Google click to deploy environment

I have used the Kafka cluster (with replication) click to deploy container from Google on kubernetes. How do I expose the brokers so I can consume from an external consumer? I'm very new to kunernetes.
I have tried exposing the broker nodes with a load balancer but the external ip given
I opened the port with a firewall rule
But when connecting from my consumer it throws an error about being disconnected
Any help would be great, I can provide more info if asked.
You cannot use a load balancer. Kafka clients must talk directly to the brokers.
Firewall is a good step, but you need to ensure each of the brokers are exposed properly via advertised.listeners within and outside of the VPC. Refer blog post.
Alternative, within GKE, you can run Strimzi Operator, which handles Kubernetes resources for you with regard to the Kafka cluster.

Configuring kafka connect with multi brokers

Steps
I have used two kafka brokers and I have started zookeeper,kafka server and kafka connect services.
I have one source type kafka connector which can be used for getting data from Database.
If i start the connector[connector 1] by using the rest API, then it will hit any one kafka server [Server 1] using load balancer.After that server 1 will store and running the connector.But server 2 does not know the connector [connector 1] which is running in the server 1.
Expectation
So if the kafka server 1 is down, then the another kafka server 2 should be able to run the connector in the failed kafka server 1.
While starting the connector, kafka server should know how many connectors are in running, so that if any one broker failed to do the job then another server will be able to continue the job.
Reality
Another Kafka server 2 which is not doing the job as per the requirement.
is there any thing to make it by configuration setup with kafka?.
Kindly suggest me some ideas.
Kafka Server 1
Kafka Server 2
It appears that you have started all processes in single pods.
You should run Kafka, Zookeeper, and Connect all as separate services in different pods.
I suggest you refer the Confluent or Strimzi sites to find Kafka Kubernetes Helm Charts / Operators
But to answer the question - You could give one or more broker to connect-distributed.properties bootstrap.server value. Then each broker is connected to as part of the Kafka cluster, and will reconnect in the event that one broker is unavailable
"Kakfa servers" (brokers) do not run Connectors
If you want to run a cluster of connect workers, you also need to setup their rest.advertised.listener address so that they can communicate with each other.

Can Kafka Connect consume data from a separate kerberized Kafka instance and then route to Splunk?

My pipeline is:
Kerberized Kafka --> Logstash (hosted on a different server) --> Splunk.
Can I replace the Logstash component with Kafka Connect?
Could you point me to a resource/guide where I can use kerberized Kafka as a source for my Kafka connect (which is hosted separately)?
From the documentation, what I understood is that if Kafka Connect is hosted on the same cluster as that of Kafka, that's quite possible. But I don't have that option right now, as our Kafka cluster is multi-tenant and hence not approved for additional processes on the cluster.
Kerberos keytabs aren't commonly machine/JVM specific, so yes, Kafka Connect should be able to be configured very similarly to Logstash since both are JVM processes using native Kafka protocol.
You shouldn't run Connect on the brokers anyway
If you can't add Kafka Connect to an existing Kafka cluster, you will have to spin up a separate Kafka Connect (Cluster or standalone).
I've written about it here: enter link description here

Kafka and Kafka Connect deployment environment

if I already have Kafka running on premises, is Kafka Connect just a configuration on top of my existing Kafka, or does Kafka Connect require it's own Server/Environment separate from that of my existing Kafka?
Kafka Connect is part of Apache Kafka, but it runs as a separate process, called a Kafka Connect Worker. Except in a sandbox environment, you would usually deploy it on a separate machine/node from your Kafka brokers.
This diagram shows conceptually how it runs, separate from your brokers:
You can run Kafka Connect on a single node, or as part of a cluster (for throughput and redundancy).
You can read more here about installation and configuration and architecture of Kafka Connect.
Kafka Connect is its own configuration on top of your bootstrap-server's configuration.
For Kafka Connect you can choose between a standalone server or distributed connect servers and you'll have to update the corresponding properties file to point to your currently running Kafka server(s).
Look under {kafka-root}/config and you'll see
You'll basically update connect-standalone or connect-distributed properties based on your need.

Apache Kafka consumer groups and microservices running on Kubernetes, are they compatible?

So far, I have been using Spring Boot apps (with Spring Cloud Stream) and Kafka running without any supporting infrastructure (PaaS).
Since our corporate platform is running on Kubernetes we need to move those Spring Boot apps into K8s to allow the apps to scale and so on. Obviously there will be more than one instance of every application so we will define a consumer group per application to ensure the unique delivery and processing of every message.
Kafka will be running outside Kubernetes.
Now my doubt is: since the apps deployed on k8s are accessed through the k8s service that abstracts the underlying pods, and individual application pods can't be access directly outside of the k8s cluster, Kafka won't know how to call individual instances of the consumer group to deliver the messages, will it?
How can I make them work together?
Kafka brokers do not push data to clients. Rather clients poll() and pull data from the brokers. As long as the consumers can connect to the bootstrap servers and you set the Kafka brokers to advertise an IP and port that the clients can connect to and poll() then it will all work fine.
Can Spring Cloud Data Flow solve your requirement to control the number of instances deployed?
and, there is a community released Spring Cloud Data Flow server for OpenShift:
https://github.com/donovanmuller/spring-cloud-dataflow-server-openshift