Kafka Connect Fluentd Connector

kafka-connect-fluentd is a Kafka Connector for copying data between Kafka and Fluentd. kafka-connect-fluentd can be alternative to fluent-plugin-kafka.

Installation

You can download and install kafka-connect-fluentd from Maven Central.

For more details, see Installing Plugins.

Running Kafka and Kafka Connector Workers

See Running Workers.

Run Apache Kafka:

(on terminal 1)
$ ./bin/zookeeper-server-start.sh config/zookeeper.properties 
(on terminal 2)
$ ./bin/kafka-server-start.sh config/server.properties

Run kafka-connect-fluentd (FluentdSourceConnector/FluentdSinkConnector):

(on terminal 3)
$ bin/connect-standalone.sh config/connect-standalone.properties \
    /path/to/kafka-connect-fluentd/config/FluentdSourceConnector.properties \
    /path/to/kafka-connect-fluentd/config/FluentdSinkConnector.properties

NOTE: Copy jar file to CLASSPATH or change plugin.path in connect-standalone.properties. Use same topics in FluentdSourceConnector.properties and FluentdSinkConnector.properties.

FluentdSourceConnector.properties:

name=FluentdSourceConnector
tasks.max=1
connector.class=org.fluentd.kafka.FluentdSourceConnector
fluentd.port=24224
fluentd.bind=0.0.0.0

fluentd.worker.pool.size=1
fluentd.counter.enabled=true

FluentdSinkConnector.properties:

name=FluentdSinkConnector
topics=fluentd-test
tasks.max=1
connector.class=org.fluentd.kafka.FluentdSinkConnector
fluentd.connect=localhost:24225

Setup Fluentd:

See also Fluentd Installation.

(on terminal 4)
$ git clone https://github.com/fluent/fluentd.git
$ cd fluentd
$ bundle install

Run Fluentd:

(on terminal 4)
$ bundle exec fluentd -c fluent.conf

fluent.conf:

<source>
  @type forward
  port 24225
</source>
<match fluentd-test>
  @type stdout
</match>

And emit records:

(on terminal 5)
$ cd fluentd
$ echo '{"messmages": "Hi, Kafka connect!"}' | bundle exec fluent-cat fluentd-test --time-as-integer

NOTE: Specify tag same as topics in FluentdSourceConnector.properties and FluentdSinkConnector.properties.

See also kafka-connect benchmark scripts.

Configuration for FluentdSourceConnector

See also Influent.

• fluentd.port
  • Port number to listen. Default: 24224
• fluentd.bind
  • Bind address to listen. Default: 0.0.0.0
• fluentd.chunk.size.limit
  • Allowable chunk size. Default: Long.MAX_VALUE
• fluentd.backlog
  • The maximum number of pending connections for a server. Default: 0
• fluentd.send.buffer.bytes
  • SO_SNDBUF for forward connection. 0 means system default value. Default: 0
• fluentd.receve.buffer.bytes
  • SO_RCVBUF for forward connection. 0 means system default value. Default: 0
• fluentd.keep.alive.enabled
  • If true, SO_KEEPALIVE is enabled. Default: true
• fluentd.tcp.no.delay.enabled
  • If true, TCP_NODELAY is enabled. Default: true
• fluentd.worker.pool.size
  • Event loop pool size. 0 means auto. Default: 0
• fluentd.transport
  • Set Fluentd transport protocol to tcp or tls. Default: tcp
• fluentd.tls.versions
  • TLS version. TLS, TLSv1, TLSv1.1 or TLSv1.2. Default: TLSv1.2
• fluentd.tls.ciphers
  • Cipher suites
• fluentd.keystore.path
  • Path to keystore
• fluentd.keystore.password
  • Password for keystore
• fluentd.key.password
  • Password for key
• kafka.topic
  • Topic for Kafka. null means using Fluentd’s tag for topic dynamically. Default: null
• fluentd.schemas.enable
  • Enable schemas for messages. Default: true
• fluentd.counter.enabled
  • For developer only Enable counter for messages/sec. Default: false

Configuration for FluentdSinkConnector

See also Fluency.

• fluentd.connect
  • Connection specs for Fluentd. Default: localhost:24224
• fluentd.client.max.buffer.bytes
  • Max buffer size.
• fluentd.client.buffer.chunk.initial.bytes
  • Initial size of buffer chunk. Default: 1048576 (1MiB)
• fluentd.client.buffer.chunk.retention.bytes
  • Retention size of buffer chunk. Default: 4194304 (4MiB)
• fluentd.client.flush.interval
  • Buffer flush interval in msec. Default: 600(msec)
• fluentd.client.ack.response.mode
  • Enable/Disable ack response mode. Default: false
• fluentd.client.file.backup.dir
  • Enable/Disable file backup mode. Default: false
• fluentd.client.wait.until.buffer.flushed
  • Max wait until all buffers are flushed in sec. Default: 60(sec)
• fluentd.client.wait.until.flusher.terminated
  • Max wait until the flusher is terminated in sec. Default: 60(sec)
• fluentd.client.jvm.heap.buffer.mode
  • If true use JVM heap memory for buffer pool. Default: false
• fluentd.client.timestamp.integer
  • If true, use integer timestamp (unix timestamp). Default: false

NOTE: Fluency doesn’t support SSL/TLS yet

Example of SSL/TLS support with Fluentd

FluentdSourceConnector.properties

name=FluentdSourceConnector
tasks.max=1
connector.class=org.fluentd.kafka.FluentdSourceConnector
fluentd.port=24224
fluentd.bind=0.0.0.0
fluentd.transport=tls
fluentd.keystore.path=/path/to/influent-server.jks
fluentd.keystore.password=password-for-keystore
fluentd.key.password=password-for-key

fluent.conf

<source>
  @type dummy
  dummy {"message": "this is test"}
  tag test
</source>

<filter test>
  @type stdout
</filter>
<match test>
  @type forward
  transport tls
  tls_cert_path /path/to/ca_cert.pem
  # tls_verify_hostname false # for test
  heartbeat_type none
  <server>
    # first server
    host 127.0.0.1
    port 24224
  </server>
  <buffer>
    flush_interval 1
  </buffer>
</match>

Run kafka-connect-fluentd and then run Fluentd with above configuration:

(on terminal 1)
$ ./bin/zookeeper-server-start.sh config/zookeeper.properties
(on terminal 2)
$ ./bin/kafka-server-start.sh config/server.properties
(on terminal 3)
$ bin/connect-standalone.sh config/connect-standalone.properties \
    /path/to/kafka-connect-fluentd/config/FluentdSourceConnector.properties \
    /path/to/connect-file-sink.properties
(on terminal 4)
$ fluentd -c fluent.conf

License

Apache License, Version 2.0