com.microsoft.azure.functions.annotation

Annotation Type KafkaOutput

@Target(value=PARAMETER)
 @Retention(value=RUNTIME)
public @interface KafkaOutput

Place this on a parameter whose value would be published to Kafka. The parameter type should be OutputBinding<T>, where T could be one of:

• Any native Java types such as int, String, byte[]
• Any POJO type

The following example shows a Java function that produce a message to the Kafka cluster, using event provided in the body of an HTTP Post request.

  @FunctionName("kafkaInupt-Java")

 public String input(
     @HttpTrigger(name = "request", methods = {HttpMethod.POST}, authLevel = AuthorizationLevel.ANONYMOUS)
     final String message,
     @KafkaOutput(name = "event", topic = "users", brokerList="broker:29092") OutputBinding<String< output,
    final ExecutionContext context) {
     context.getLogger().info("Message:" + message);
     output.setValue(message);
     return "{ \"id\": \"" + System.currentTimeMillis() + "\", \"description\": \"" + message + "\" }";
 }
 

Since:

1.4.0

Required Element Summary

Required Elements

Modifier and Type	Required Element and Description
String	brokerList Defines the BrokerList.
String	name The variable name used in function.json.
String	topic Defines the Topic.

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
com.microsoft.azure.functions.BrokerAuthenticationMode	authenticationMode SASL mechanism to use for authentication.
int	batchSize Defines the maximum number of messages batched in one MessageSet.
String	dataType Defines how Functions runtime should treat the parameter value.
boolean	enableIdempotence When set to `true`, the producer will ensure that messages are successfully produced exactly once and in the original produce order.
int	maxMessageBytes Defines the maximum transmit message size.
int	maxRetries How many times to retry sending a failing Message.
int	messageTimeoutMs Local message timeout.
String	password SASL password with the PLAIN and SASL-SCRAM-..
com.microsoft.azure.functions.BrokerProtocol	protocol Gets or sets the security protocol used to communicate with brokers default is PLAINTEXT
int	requestTimeoutMs The ack timeout of the producer request in milliseconds.
String	sslCaLocation Path to CA certificate file for verifying the broker's certificate.
String	sslCertificateLocation Path to client's certificate.
String	sslKeyLocation Path to client's private key (PEM) used for authentication.
String	sslKeyPassword Password for client's certificate.
String	username SASL username with the PLAIN and SASL-SCRAM-..

Element Detail

name

public abstract String name

The variable name used in function.json.

Returns:

The variable name used in function.json.

topic

public abstract String topic

Defines the Topic.

Returns:

The topic name.

brokerList

public abstract String brokerList

Defines the BrokerList.

Returns:

The brokerList name string.

dataType

public abstract String dataType

Defines how Functions runtime should treat the parameter value. Possible values are:

• "" or string: treat it as a string whose value is serialized from the parameter
• binary: treat it as a binary data whose value comes from for example OutputBinding<byte[]<

Returns:

The dataType which will be used by the Functions runtime.

Default:

""

maxMessageBytes

public abstract int maxMessageBytes

Defines the maximum transmit message size. Default: 1MB

Returns:

The maximum trnasmit message size.

Default:

1000012

batchSize

public abstract int batchSize

Defines the maximum number of messages batched in one MessageSet. default: 10000

Returns:

The maximum number of messages batched in one MessageSet.

Default:

10000

enableIdempotence

public abstract boolean enableIdempotence

When set to `true`, the producer will ensure that messages are successfully produced exactly once and in the original produce order. default: false

Returns:

whether idempotence is enabled.

Default:

false

messageTimeoutMs

public abstract int messageTimeoutMs

Local message timeout. This value is only enforced locally and limits the time a produced message waits for successful delivery. A time of 0 is infinite. This is the maximum time used to deliver a message (including retries). Delivery error occurs when either the retry count or the message timeout are exceeded. default: 300000

Returns:

The local message timeout.

Default:

300000

requestTimeoutMs

public abstract int requestTimeoutMs

The ack timeout of the producer request in milliseconds. default: 5000

Returns:

The ack timeout of the producer request in milliseconds.

Default:

5000

maxRetries

public abstract int maxRetries

How many times to retry sending a failing Message. **Note:** default: 2 Retrying may cause reordering unless EnableIdempotence is set to true.

Returns:

The number of the max retries.

See Also:

enableIdempotence()

Default:

2

authenticationMode

public abstract com.microsoft.azure.functions.BrokerAuthenticationMode authenticationMode

SASL mechanism to use for authentication. Default: PLAIN

Returns:

The SASL mechanism.

Default:

com.microsoft.azure.functions.BrokerAuthenticationMode.NOTSET

username

public abstract String username

SASL username with the PLAIN and SASL-SCRAM-.. mechanisms Default: ""

Returns:

The SASL username.

Default:

""

password

public abstract String password

SASL password with the PLAIN and SASL-SCRAM-.. mechanisms Default is plaintext security.protocol in librdkafka

Returns:

The SASL password.

Default:

""

protocol

public abstract com.microsoft.azure.functions.BrokerProtocol protocol

Gets or sets the security protocol used to communicate with brokers default is PLAINTEXT

Returns:

The protocol.

Default:

com.microsoft.azure.functions.BrokerProtocol.NOTSET

sslKeyLocation

public abstract String sslKeyLocation

Path to client's private key (PEM) used for authentication. Default "" ssl.key.location in librdkafka

Returns:

The ssl key location.

Default:

""

sslCaLocation

public abstract String sslCaLocation

Path to CA certificate file for verifying the broker's certificate. ssl.ca.location in librdkafka

Returns:

The ssl ca location.

Default:

""

sslCertificateLocation

public abstract String sslCertificateLocation

Path to client's certificate. ssl.certificate.location in librdkafka

Returns:

The ssl certificate location.

Default:

""

sslKeyPassword

public abstract String sslKeyPassword

Password for client's certificate. ssl.key.password in librdkafka

Returns:

The ssl key password.

Default:

""