PublishKafka_2_6

Description:

Sends the contents of a FlowFile as a message to Apache Kafka using the Kafka 2.6 Producer API.The messages to send may be individual FlowFiles or may be delimited, using a user-specified delimiter, such as a new-line. The complementary NiFi processor for fetching messages is ConsumeKafka_2_6.

Additional Details...

Tags:

Apache, Kafka, Put, Send, Message, PubSub, 2.6

Properties:

In the list below, the names of required properties appear in bold. Any other properties (not in bold) are considered optional. The table also indicates any default values, and whether a property supports the NiFi Expression Language.

Display NameAPI NameDefault ValueAllowable ValuesDescription
Kafka Brokersbootstrap.serverslocalhost:9092Comma-separated list of Kafka Brokers in the format host:port
Supports Expression Language: true (will be evaluated using variable registry only)
Topic NametopicThe name of the Kafka Topic to publish to.
Supports Expression Language: true (will be evaluated using flow file attributes and variable registry)
Use Transactionsuse-transactionstrue
  • true
  • false
Specifies whether or not NiFi should provide Transactional guarantees when communicating with Kafka. If there is a problem sending data to Kafka, and this property is set to false, then the messages that have already been sent to Kafka will continue on and be delivered to consumers. If this is set to true, then the Kafka transaction will be rolled back so that those messages are not available to consumers. Setting this to true requires that the <Delivery Guarantee> property be set to "Guarantee Replicated Delivery."
Transactional Id Prefixtransactional-id-prefixWhen Use Transaction is set to true, KafkaProducer config 'transactional.id' will be a generated UUID and will be prefixed with this string.
Supports Expression Language: true (will be evaluated using variable registry only)

This Property is only considered if the [Use Transactions] Property has a value of "true".
Message Demarcatormessage-demarcatorSpecifies the string (interpreted as UTF-8) to use for demarcating multiple messages within a single FlowFile. If not specified, the entire content of the FlowFile will be used as a single message. If specified, the contents of the FlowFile will be split on this delimiter and each section sent as a separate Kafka message. To enter special character such as 'new line' use CTRL+Enter or Shift+Enter, depending on your OS.
Supports Expression Language: true (will be evaluated using flow file attributes and variable registry)
Failure StrategyFailure StrategyRoute to Failure
  • Route to Failure When unable to publish records to Kafka, the FlowFile will be routed to the failure relationship.
  • Rollback When unable to publish records to Kafka, the FlowFile will be placed back on the queue so that it will be retried. For flows where FlowFile ordering is important, this strategy can be used along with ensuring that the each processor uses only a single Concurrent Task.
Specifies how the processor handles a FlowFile if it is unable to publish the data to Kafka
Delivery GuaranteeacksGuarantee Replicated Delivery
  • Best Effort FlowFile will be routed to success after successfully sending the content to a Kafka node, without waiting for any acknowledgment from the node at all. This provides the best performance but may result in data loss.
  • Guarantee Single Node Delivery FlowFile will be routed to success if the message is received by a single Kafka node, whether or not it is replicated. This is faster than <Guarantee Replicated Delivery> but can result in data loss if a Kafka node crashes
  • Guarantee Replicated Delivery FlowFile will be routed to failure unless the message is replicated to the appropriate number of Kafka Nodes according to the Topic configuration
Specifies the requirement for guaranteeing that a message is sent to Kafka. Corresponds to Kafka's 'acks' property.
Attributes to Send as Headers (Regex)attribute-name-regexA Regular Expression that is matched against all FlowFile attribute names. Any attribute whose name matches the regex will be added to the Kafka messages as a Header. If not specified, no FlowFile attributes will be added as headers.
Message Header Encodingmessage-header-encodingUTF-8For any attribute that is added as a message header, as configured via the <Attributes to Send as Headers> property, this property indicates the Character Encoding to use for serializing the headers.
Security Protocolsecurity.protocolPLAINTEXT
  • PLAINTEXT
  • SSL
  • SASL_PLAINTEXT
  • SASL_SSL
Security protocol used to communicate with brokers. Corresponds to Kafka Client security.protocol property
SASL Mechanismsasl.mechanismGSSAPI
  • GSSAPI General Security Services API for Kerberos authentication
  • PLAIN Plain username and password authentication
  • SCRAM-SHA-256 Salted Challenge Response Authentication Mechanism using SHA-512 with username and password
  • SCRAM-SHA-512 Salted Challenge Response Authentication Mechanism using SHA-256 with username and password
SASL mechanism used for authentication. Corresponds to Kafka Client sasl.mechanism property
Kerberos Credentials Servicekerberos-credentials-serviceController Service API:
KerberosCredentialsService
Implementation: KeytabCredentialsService		Service supporting generalized credentials authentication with Kerberos
Kerberos User Servicekerberos-user-serviceController Service API:
SelfContainedKerberosUserService
Implementations: KerberosKeytabUserService
KerberosTicketCacheUserService		Service supporting user authentication with Kerberos
Kerberos Service Namesasl.kerberos.service.nameThe service name that matches the primary name of the Kafka server configured in the broker JAAS configuration
Supports Expression Language: true (will be evaluated using variable registry only)
Kerberos Principalsasl.kerberos.principalPrincipal used for authentication with Kerberos
Supports Expression Language: true (will be evaluated using variable registry only)
Kerberos Keytabsasl.kerberos.keytabKeytab credentials used for authentication with Kerberos

This property requires exactly one file to be provided..

Supports Expression Language: true (will be evaluated using variable registry only)
Usernamesasl.usernameUsername provided with configured password when using PLAIN or SCRAM SASL Mechanisms
Supports Expression Language: true (will be evaluated using variable registry only)

This Property is only considered if the [SASL Mechanism] Property is set to one of the following values: [PLAIN], [SCRAM-SHA-512], [SCRAM-SHA-256]
Passwordsasl.passwordPassword provided with configured username when using PLAIN or SCRAM SASL Mechanisms
Sensitive Property: true
Supports Expression Language: true (will be evaluated using variable registry only)

This Property is only considered if the [SASL Mechanism] Property is set to one of the following values: [PLAIN], [SCRAM-SHA-512], [SCRAM-SHA-256]
AWS Profile Nameaws.profile.nameThe Amazon Web Services Profile to select when multiple profiles are available.
Supports Expression Language: true (will be evaluated using flow file attributes and variable registry)

This Property is only considered if the [SASL Mechanism] Property
Token Authenticationsasl.token.authfalse
  • true
  • false
Enables or disables Token authentication when using SCRAM SASL Mechanisms

This Property is only considered if the [SASL Mechanism] Property is set to one of the following values: [SCRAM-SHA-512], [SCRAM-SHA-256]
SSL Context Servicessl.context.serviceController Service API:
SSLContextService
Implementations: StandardSSLContextService
StandardRestrictedSSLContextService		Service supporting SSL communication with Kafka brokers
Kafka Keykafka-keyThe Key to use for the Message. If not specified, the flow file attribute 'kafka.key' is used as the message key, if it is present.Beware that setting Kafka key and demarcating at the same time may potentially lead to many Kafka messages with the same key.Normally this is not a problem as Kafka does not enforce or assume message and key uniqueness. Still, setting the demarcator and Kafka key at the same time poses a risk of data loss on Kafka. During a topic compaction on Kafka, messages will be deduplicated based on this key.
Supports Expression Language: true (will be evaluated using flow file attributes and variable registry)
Key Attribute Encodingkey-attribute-encodingUTF-8 Encoded
  • UTF-8 Encoded The key is interpreted as a UTF-8 Encoded string.
  • Hex Encoded The key is interpreted as arbitrary binary data that is encoded using hexadecimal characters with uppercase letters.
FlowFiles that are emitted have an attribute named 'kafka.key'. This property dictates how the value of the attribute should be encoded.
Max Request Sizemax.request.size1 MBThe maximum size of a request in bytes. Corresponds to Kafka's 'max.request.size' property and defaults to 1 MB (1048576).
Acknowledgment Wait Timeack.wait.time5 secsAfter sending a message to Kafka, this indicates the amount of time that we are willing to wait for a response from Kafka. If Kafka does not acknowledge the message within this time period, the FlowFile will be routed to 'failure'.
Max Metadata Wait Timemax.block.ms5 secThe amount of time publisher will wait to obtain metadata or wait for the buffer to flush during the 'send' call before failing the entire 'send' call. Corresponds to Kafka's 'max.block.ms' property
Supports Expression Language: true (will be evaluated using variable registry only)
Partitioner classpartitioner.classDefaultPartitioner
  • RoundRobinPartitioner Messages will be assigned partitions in a round-robin fashion, sending the first message to Partition 1, the next Partition to Partition 2, and so on, wrapping as necessary.
  • DefaultPartitioner The default partitioning strategy will choose the sticky partition that changes when the batch is full (See KIP-480 for details about sticky partitioning).
  • Expression Language Partitioner Interprets the <Partition> property as Expression Language that will be evaluated against each FlowFile. This Expression will be evaluated once against the FlowFile, so all Records in a given FlowFile will go to the same partition.
Specifies which class to use to compute a partition id for a message. Corresponds to Kafka's 'partitioner.class' property.
PartitionpartitionSpecifies which Partition Records will go to.
Supports Expression Language: true (will be evaluated using flow file attributes and variable registry)
Compression Typecompression.typenone
  • none
  • gzip
  • snappy
  • lz4
This parameter allows you to specify the compression codec for all data generated by this producer.

Dynamic Properties:

Supports Sensitive Dynamic Properties: No

Dynamic Properties allow the user to specify both the name and value of a property.

NameValueDescription
The name of a Kafka configuration property.The value of a given Kafka configuration property.These properties will be added on the Kafka configuration after loading any provided configuration properties. In the event a dynamic property represents a property that was already set, its value will be ignored and WARN message logged. For the list of available Kafka properties please refer to: http://kafka.apache.org/documentation.html#configuration.
Supports Expression Language: true (will be evaluated using variable registry only)

Relationships:

NameDescription
successFlowFiles for which all content was sent to Kafka.
failureAny FlowFile that cannot be sent to Kafka will be routed to this Relationship

Reads Attributes:

NameDescription
kafka.tombstoneIf this attribute is set to 'true', if the processor is not configured with a demarcator and if the FlowFile's content is null, then a tombstone message with zero bytes will be sent to Kafka.

Writes Attributes:

NameDescription
msg.countThe number of messages that were sent to Kafka for this FlowFile. This attribute is added only to FlowFiles that are routed to success. If the <Message Demarcator> Property is not set, this will always be 1, but if the Property is set, it may be greater than 1.

State management:

This component does not store state.

Restricted:

This component is not restricted.

Input requirement:

This component requires an incoming relationship.

System Resource Considerations:

None specified.