Table of Contents *generated with DocToc*

• [Kafka Puppet Module](#kafka-puppet-module)
• [Requirements](#requirements)
• [Usage](#usage)
  • [Kafka (Clients)](#kafka)
  • [Kafka Broker Servers](#kafka-broker-server)
  • [Custom Zookeeper Chroot](#custom-zookeeper-chroot)
  • [Kafka Mirror](#kafka-mirror)

Kafka Puppet Module

A Puppet module for installing and managing Apache Kafka brokers.

This module is currently being maintained by The Wikimedia Foundation in Gerrit at operations/puppet/kafka and mirrored here on GitHub. It was originally developed for 0.7.2 at https://github.com/wikimedia/puppet-kafka-0.7.2.

1. Requirements
2. Java
3. An Kafka 0.8 package. You can build a .deb package using the operations/debs/kafka debian branch, or just install using this prebuilt .deb
4. A running zookeeper cluster. You can set one up using WMF's puppet-zookeeper module.

Usage

Kafka (Clients)

puppet
# Install the kafka libraries and client packages.
class { 'kafka': }

This will install the kafka-common and kafka-cli which includes /usr/bin/kafka, useful for running client (console-consumer, console-producer, etc.) commands.

Kafka Broker Server

puppet
# Include Kafka Broker Server.
class { 'kafka::server':
    log_dirs         => ['/var/spool/kafka/a', '/var/spool/kafka/b'],
    brokers          => {
        'kafka-node01.example.com' => { 'id' => 1, 'port' => 12345 },
        'kafka-node02.example.com' => { 'id' => 2 },
    },
    zookeeper_hosts  => ['zk-node01:2181', 'zk-node02:2181', 'zk-node03:2181'],
    zookeeper_chroot => '/kafka/cluster_name',
}

log_dirs defaults to a single ['/var/spool/kafka], but you may specify multiple Kafka log data directories here. This is useful for spreading your topic partitions across multiple disks.

The brokers parameter is a Hash keyed by $::fqdn. Each value is another Hash that contains config settings for that kafka host. id is required and must be unique for each Kafka Broker Server host. port is optional, and defaults to 9092.

Each Kafka Broker Server's broker_id and port properties in server.properties will be set based by looking up the node's $::fqdn in the hosts Hash passed into the kafka base class.

zookeeper_hosts is an array of Zookeeper host:port pairs. zookeeper_chroot is optional, and allows you to specify a Znode under which Kafka will store its metadata in Zookeeper. This is useful if you want to use a single Zookeeper cluster to manage multiple Kafka clusters.

Kafka Mirror

Kafka MirrorMaker will allow you to mirror data from multiple Kafka clusters into another. This is useful for cross DC replication and for aggregation.

puppet
# Mirror the 'main' and 'secondary' Kafka clusters
# to the 'aggregate' Kafka cluster.
kafka::mirror::consumer { 'main':
    mirror_name   => 'aggregate',
    zookeeper_url => 'zk:2181/kafka/main',
}
kafka::mirror::consumer { 'secondary':
    mirror_name   => 'aggregate',
    zookeeper_url => 'zk:2181/kafka/secondary',
}
kafka::mirror { 'aggregate':
    destination_brokers => ['ka01:9092','ka02:9092'],
    whitelist           => 'these_topics_only.*',
}

Note that the kafka-mirror service does not subscribe to its config files. If you make changes, you will have to restart the service manually.

jmxtrans monitoring

kafka::server::jmxtrans and kafka::mirror::jmxtrans configure useful jmxtrans JSON config objects that can be used to tell jmxtrans to send to any output writer (Ganglia, Graphite, etc.). To you use this, you will need the puppet-jmxtrans module.

puppet
# Include this class on each of your Kafka Broker Servers.
class { '::kafka::server::jmxtrans':
    ganglia => 'ganglia.example.com:8649',
}

This will install jmxtrans and render JSON config files for sending JVM and Kafka Broker stats to Ganglia. See [kafka-jmxtrans.json.md](kafka-jmxtrans.json.md) for a fully rendered jmxtrans Kafka Broker JSON config file.

# Declare this define on hosts where you run Kafka MirrorMaker.
kafka::mirror::jmxtrans { 'aggregate':
    statsd => 'statsd.example.org:8125'
}

This will install jmxtrans and render JSON config files for sending JVM and Kafka MirrorMaker (consumers and producer) stats to statsd.