Configuration Reference for HDFS 3 Source Connector for Confluent Platform

To use this connector, specify the name of the connector class in the connector.class configuration property.

connector.class=io.confluent.connect.hdfs3.Hdfs3SourceConnector

Connector-specific configuration properties are described below.

HDFS3 Parameters

hdfs.url

The HDFS connection URL. This configuration has the format of hdfs://hostname:port and specifies the HDFS to export data to. This property is deprecated and will be removed in future releases. Use store.url instead.

  • Type: string
  • Default: null
  • Importance: high
hadoop.conf.dir

The Hadoop configuration directory.

  • Type: string
  • Default: “”
  • Importance: high
hadoop.home

The Hadoop home directory.

  • Type: string
  • Default: “”
  • Importance: high
hdfs.poll.interval.ms

Frequency in milliseconds to poll for new or removed folders. This may result in updated task configurations starting to poll for data in added folders or stopping polling for data in removed folders.

  • Type: long
  • Default: 300000
  • Importance: medium

Security Parameters

hdfs.authentication.kerberos

Configuration indicating whether HDFS is using Kerberos for authentication.

  • Type: boolean
  • Default: false
  • Importance: high
  • Dependents: connect.hdfs.principal, connect.hdfs.keytab, hdfs.namenode.principal, kerberos.ticket.renew.period.ms
connect.hdfs.keytab

The path to the keytab file for the HDFS connector principal. This keytab file should only be readable by the connector user.

  • Type: string
  • Default: “”
  • Importance: high
connect.hdfs.principal

The principal to use when HDFS is using Kerberos to for authentication.

  • Type: string
  • Default: “”
  • Importance: high
hdfs.namenode.principal

The principal for HDFS Namenode.

  • Type: string
  • Default: “”
  • Importance: high
kerberos.ticket.renew.period.ms

The period in milliseconds to renew the Kerberos ticket.

  • Type: long
  • Default: 3600000
  • Importance: low

Connector Parameters

format.class

Class responsible for converting source objects to source records.

  • Type: class
  • Default: io.confluent.connect.hdfs3.format.avro.AvroFormat
  • Importance: high

You can use following four type of formatter:

  • io.confluent.connect.hdfs3.format.avro.AvroFormat
  • io.confluent.connect.hdfs3.format.json.JsonFormat
  • io.confluent.connect.hdfs3.format.string.StringFormat
  • io.confluent.connect.hdfs3.format.parquet.ParquetFormat
schema.cache.size

The size of the schema cache used in the Avro converter.

  • Type: int
  • Default: 50
  • Valid Values: [1,…]
  • Importance: low
record.batch.max.size

The maximum amount of records to return each time HDFS3 is polled.

  • Type: int
  • Default: 200
  • Valid Values: [1,…]
  • Importance: medium

Auto topic creation

For more information about Auto topic creation, see Configuring Auto Topic Creation for Source Connectors.

Configuration properties accept regular expressions (regex) that are defined as Java regex.

topic.creation.groups

A list of group aliases that are used to define per-group topic configurations for matching topics. A default group always exists and matches all topics.

  • Type: List of String types
  • Default: empty
  • Possible Values: The values of this property refer to any additional groups. A default group is always defined for topic configurations.
topic.creation.$alias.replication.factor

The replication factor for new topics created by the connector. This value must not be larger than the number of brokers in the Kafka cluster. If this value is larger than the number of Kafka brokers, an error occurs when the connector attempts to create a topic. This is a required property for the default group. This property is optional for any other group defined in topic.creation.groups. Other groups use the Kafka broker default value.

  • Type: int
  • Default: n/a
  • Possible Values: >= 1 for a specific valid value or -1 to use the Kafka broker’s default value.
topic.creation.$alias.partitions

The number of topic partitions created by this connector. This is a required property for the default group. This property is optional for any other group defined in topic.creation.groups. Other groups use the Kafka broker default value.

  • Type: int
  • Default: n/a
  • Possible Values: >= 1 for a specific valid value or -1 to use the Kafka broker’s default value.
topic.creation.$alias.include

A list of strings that represent regular expressions that match topic names. This list is used to include topics with matching values, and apply this group’s specific configuration to the matching topics. $alias applies to any group defined in topic.creation.groups. This property does not apply to the default group.

  • Type: List of String types
  • Default: empty
  • Possible Values: Comma-separated list of exact topic names or regular expressions.
topic.creation.$alias.exclude

A list of strings representing regular expressions that match topic names. This list is used to exclude topics with matching values from getting the group’s specfic configuration. $alias applies to any group defined in topic.creation.groups. This property does not apply to the default group. Note that exclusion rules override any inclusion rules for topics.

  • Type: List of String types
  • Default: empty
  • Possible Values: Comma-separated list of exact topic names or regular expressions.
topic.creation.$alias.${kafkaTopicSpecificConfigName}

Any of the Changing Broker Configurations Dynamically for the version of the Kafka broker where the records will be written. The broker’s topic-level configuration value is used if the configuration is not specified for the rule. $alias applies to the default group as well as any group defined in topic.creation.groups.

  • Type: property values
  • Default: Kafka broker value

Storage Parameters

topics.dir

Top level directory where data was stored to be re-ingested by Kafka.

  • Type: string
  • Default: topics
  • Importance: high
directory.delim

Directory delimiter pattern.

  • Type: string
  • Default: /
  • Importance: medium
behavior.on.error

Sets how the connector handles errors that occur when processing records.

  • Type: string
  • Default: fail
  • Valid Values: Matches: fail, ignore, log
  • Importance: medium

Partitioner Parameters

partitioner.class The partitioner to use when reading data to the store.. The following partitioners are available:

  • io.confluent.connect.storage.partitioner.DefaultPartitioner
  • io.confluent.connect.storage.partitioner.DailyPartitioner
  • io.confluent.connect.storage.partitioner.HourlyPartitioner
  • io.confluent.connect.storage.partitioner.FieldPartitioner
  • io.confluent.connect.storage.partitioner.TimeBasedPartitioner
    • Type: class
    • Default: io.confluent.connect.storage.partitioner.DefaultPartitioner
    • Importance: high
partition.field.name

The name of the partitioning field when FieldPartitioner is used.

  • Type: list
  • Default: “”
  • Importance: medium
path.format

This configuration that was used to set the format of the data directories when partitioning with a TimeBasedPartitioner. For example, if you set path.format to 'year'=YYYY/'month'=MM/'day'=dd/'hour'=HH, then a valid data directories would be: /year=2015/month=12/day=07/hour=15/.

  • Type: string
  • Default: “”
  • Importance: medium
partition.duration.ms

The duration of a partition milliseconds used by TimeBasedPartitioner. The default value -1 means that we are not using TimeBasedPartitioner.

  • Type: long
  • Default: -1
  • Importance: medium
locale

The locale to use when partitioning with TimeBasedPartitioner, and used to format dates and times. For example, use en-US for US English, en-GB for UK English, or fr-FR for French (in France). These may vary by Java version; see the available locales.

  • Type: string
  • Default: “”
  • Importance: medium
timezone

The timezone to use when partitioning with TimeBasedPartitioner. Used to format and compute dates and times. All IDs must be specified in the long format, such as America/Los_Angeles, America/New_York, and Europe/Paris, or UTC. Alternatively a locale independent, fixed offset, datetime zone can be specified in form [+-]hh:mm. Support for these timezones may vary by Java version. See the available timezones within each locale, such as those within the US English locale.

  • Type: string
  • Default: “”
  • Importance: medium
timestamp.extractor

The extractor that gets the timestamp for records when partitioning with TimeBasedPartitioner. It can be set to Wallclock, Record or RecordField in order to use one of the built-in timestamp extractors or be given the fully-qualified class name of a user-defined class that extends the TimestampExtractor interface.

  • Type: string
  • Default: Wallclock
  • Importance: medium
timestamp.field

The record field to be used as timestamp by the timestamp extractor.

  • Type: string
  • Default: timestamp
  • Importance: medium

Confluent Platform license

confluent.topic.bootstrap.servers

A list of host/port pairs to use for establishing the initial connection to the Kafka cluster used for licensing. All servers in the cluster will be discovered from the initial connection. This list should be in the form host1:port1,host2:port2,.... These servers are used only for the initial connection to discover the full cluster membership, which may change dynamically, so this list need not contain the full set of servers. You may want more than one, in case a server is down.

  • Type: list
  • Importance: high
confluent.topic

Name of the Kafka topic used for Confluent Platform configuration, including licensing information.

  • Type: string
  • Default: _confluent-command
  • Importance: low
confluent.topic.replication.factor

The replication factor for the Kafka topic used for Confluent Platform configuration, including licensing information. This is used only if the topic does not already exist, and the default of 3 is appropriate for production use. If you are using a development environment with less than 3 brokers, you must set this to the number of brokers (often 1).

  • Type: int
  • Default: 3
  • Importance: low

Confluent license properties

You can put license-related properties in the connector configuration, or starting with Confluent Platform version 6.0, you can put license-related properties in the Connect worker configuration instead of in each connector configuration.

This connector is proprietary and requires a license. The license information is stored in the _confluent-command topic. If the broker requires SSL for connections, you must include the security-related confluent.topic.* properties as described below.

confluent.license

Confluent issues enterprise license keys to each subscriber. The license key is text that you can copy and paste as the value for confluent.license. A trial license allows using the connector for a 30-day trial period. A developer license allows using the connector indefinitely for single-broker development environments.

If you are a subscriber, contact Confluent Support for more information.

  • Type: string
  • Default: “”
  • Valid Values: Confluent Platform license
  • Importance: high
confluent.topic.ssl.truststore.location

The location of the trust store file.

  • Type: string
  • Default: null
  • Importance: high
confluent.topic.ssl.truststore.password

The password for the trust store file. If a password is not set access to the truststore is still available, but integrity checking is disabled.

  • Type: password
  • Default: null
  • Importance: high
confluent.topic.ssl.keystore.location

The location of the key store file. This is optional for client and can be used for two-way authentication for client.

  • Type: string
  • Default: null
  • Importance: high
confluent.topic.ssl.keystore.password

The store password for the key store file. This is optional for client and only needed if ssl.keystore.location is configured.

  • Type: password
  • Default: null
  • Importance: high
confluent.topic.ssl.key.password

The password of the private key in the key store file. This is optional for client.

  • Type: password
  • Default: null
  • Importance: high
confluent.topic.security.protocol

Protocol used to communicate with brokers. Valid values are: PLAINTEXT, SSL, SASL_PLAINTEXT, SASL_SSL.

  • Type: string
  • Default: “PLAINTEXT”
  • Importance: medium

License topic configuration

A Confluent enterprise license is stored in the _confluent-command topic. This topic is created by default and contains the license that corresponds to the license key supplied through the confluent.license property. No public keys are stored in Kafka topics.

The following describes how the default _confluent-command topic is generated under different scenarios:

  • A 30-day trial license is automatically generated for the _confluent command topic if you do not add the confluent.license property or leave this property empty (for example, confluent.license=).
  • Adding a valid license key (for example, confluent.license=<valid-license-key>) adds a valid license in the _confluent-command topic.

Here is an example of the minimal properties for development and testing.

You can change the name of the _confluent-command topic using the confluent.topic property (for instance, if your environment has strict naming conventions). The example below shows this change and the configured Kafka bootstrap server.

confluent.topic=foo_confluent-command
confluent.topic.bootstrap.servers=localhost:9092

The example above shows the minimally required bootstrap server property that you can use for development and testing. For a production environment, you add the normal producer, consumer, and topic configuration properties to the connector properties, prefixed with confluent.topic..

License topic ACLs

The _confluent-command topic contains the license that corresponds to the license key supplied through the confluent.license property. It is created by default. Connectors that access this topic require the following ACLs configured:

  • CREATE and DESCRIBE on the resource cluster, if the connector needs to create the topic.

  • DESCRIBE, READ, and WRITE on the _confluent-command topic.

    Important

    You can also use DESCRIBE and READ without WRITE to restrict access to read-only for license topic ACLs. If a topic exists, the LicenseManager will not try to create the topic.

You can provide access either individually for each principal that will use the license or use a wildcard entry to allow all clients. The following examples show commands that you can use to configure ACLs for the resource cluster and _confluent-command topic.

  1. Set a CREATE and DESCRIBE ACL on the resource cluster:

    kafka-acls --bootstrap-server localhost:9092 --command-config adminclient-configs.conf \
--add --allow-principal User:<principal> \
--operation CREATE --operation DESCRIBE --cluster

  2. Set a DESCRIBE, READ, and WRITE ACL on the _confluent-command topic:

    kafka-acls --bootstrap-server localhost:9092 --command-config adminclient-configs.conf \
--add --allow-principal User:<principal> \
--operation DESCRIBE --operation READ --operation WRITE --topic _confluent-command

Override Default Configuration Properties

You can override the replication factor using confluent.topic.replication.factor. For example, when using a Kafka cluster as a destination with less than three brokers (for development and testing) you should set the confluent.topic.replication.factor property to 1.

You can override producer-specific properties by using the producer.override.* prefix (for source connectors) and consumer-specific properties by using the consumer.override.* prefix (for sink connectors).

You can use the defaults or customize the other properties as well. For example, the confluent.topic.client.id property defaults to the name of the connector with -licensing suffix. You can specify the configuration settings for brokers that require SSL or SASL for client connections using this prefix.

You cannot override the cleanup policy of a topic because the topic always has a single partition and is compacted. Also, do not specify serializers and deserializers using this prefix; they are ignored if added.