This page explains the Apache Kafka Producer Adapter in Bridge context. If you were looking for the same information regarding the PAS Designer, refer to Apache Kafka Producer Adapter in the Designer guide.
You can use the Apache Kafka Producer Adapter to write synchronous messages to an Apache Kafka event topic. The access to Kafka can be configured statically by an alias - dynamic access is not available. The Kafka Producer supports SSL but no Kerberos authentication.
To use the Apache Kafka Producer adapter, you need basic knowledge of Apache Kafka. Refer to the Apache Kafka Documentation for any deeper insights.
Writing a Message to a Kafka Topic
You can use the Apache Kafka Producer adapter to write a message to a Kafka topic. Create an action node and assign stereotype KafkaProducerAdapter. This action node has got the following parameters:
|
Name |
Type |
Direction |
Description |
|---|---|---|---|
|
producerRecord |
Apache Kafka Producer | ApacheKafkaProducer ProducerRecord |
in |
Provide the message and the target for the adapter to send the message to a Kafka topic. |
|
recordMetaData |
Apache Kafka Producer | ApacheKafkaProducer RecordMetaData |
out |
Returns some meta data about the processing the Kafka broker has done. |
producerRecord is a complex structure that defines the message and target.The topic you want to write the message to is the only mandatory parameter.
|
Attribute |
Type |
Mandatory |
Description |
|---|---|---|---|
|
topic |
String |
|
Specify the topic the message should be sent do. |
|
partition
|
Integer |
|
Specify the partition the message should be send to. |
|
key
|
Blob |
|
Specify a key the message should be filed to. |
|
id
|
Integer |
|
Will be generated. We recommend not to set one manually. |
|
headers
|
Array of MessageHeader |
|
Specify headers if you want to provide additional information on the message content for e.g. routing or filtering use cases. |
|
value
|
Blob |
|
Specify the actual message content. Only payload of type Blob is supported. |
The Kafka Producer returns some meta data about the processing of the message.
|
Attribute |
Type |
Mandatory |
Description |
Allowed Values / Examples |
|
|---|---|---|---|---|---|
|
topic |
String |
|
Kafka topic the message has been sent to. |
|
|
|
partition
|
Integer |
|
Topic partition the message has been sent to. |
|
|
|
offset
|
Integer |
|
Offset of the message within the partition. |
|
|
|
recordId
|
Integer |
|
The message ID as provided with the call, or as generated if it has not been specified. |
|
|
|
keySize
|
Integer |
|
Actual size of the key in bytes. |
|
|
|
valueSize
|
Integer |
|
Actual size of the value in bytes. |
|
|
|
timestamp
|
DateTime |
|
A processing timestamp (UTC). See timestampType for what the timestamp refers to. |
|
|
|
timestampType
|
TimestampType |
|
Indicates what the timestamp refers to. |
NotAvailable |
Timestamp is unknown. |
|
CreateTime |
Timestamp relates to message creation time as set by a Kafka broker. |
||||
|
LogAppendTime |
Timestamp relates to the time a message was appended to a Kafka log. |
||||
|
persistedStatus
|
PersistedStatus |
|
Status of the message. |
NotPersisted |
Message was never transmitted to the broker, or failed with an error indicating it was not written to the log. |
|
Persisted |
Message was written to the log and acknowledged by the broker. |
||||
|
PossiblyPersisted |
Message was transmitted to broker, but no acknowledgement was received. |
||||
Transaction Handling
The xUML Runtime handles Apache Kafka Producer calls like is specified in the Runtime transaction concept. All producer calls within a session are wrapped into a dedicated transaction with a random unique transaction ID. These transactions can be rolled back until they have been committed.
You cannot set a custom transaction ID (transactional.id), therefore there will be no fencing.