Pulsar

Since Camel 2.24

Both producer and consumer are supported

Maven users will need to add the following dependency to their pom.xml for this component.

<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-pulsar</artifactId>
    <!-- use the same version as your Camel core version -->
    <version>x.y.z</version>
</dependency>

URI format

pulsar:[persistent|non-persistent]://tenant/namespace/topic

Configuring Options

Camel components are configured on two separate levels:

  • component level

  • endpoint level

Configuring Component Options

The component level is the highest level which holds general and common configurations that are inherited by the endpoints. For example a component may have security settings, credentials for authentication, urls for network connection and so forth.

Some components only have a few options, and others may have many. Because components typically have pre configured defaults that are commonly used, then you may often only need to configure a few options on a component; or none at all.

Configuring components can be done with the Component DSL, in a configuration file (application.properties|yaml), or directly with Java code.

Configuring Endpoint Options

Where you find yourself configuring the most is on endpoints, as endpoints often have many options, which allows you to configure what you need the endpoint to do. The options are also categorized into whether the endpoint is used as consumer (from) or as a producer (to), or used for both.

Configuring endpoints is most often done directly in the endpoint URI as path and query parameters. You can also use the Endpoint DSL and DataFormat DSL as a type safe way of configuring endpoints and data formats in Java.

A good practice when configuring options is to use Property Placeholders, which allows to not hardcode urls, port numbers, sensitive information, and other settings. In other words placeholders allows to externalize the configuration from your code, and gives more flexibility and reuse.

The following two sections lists all the options, firstly for the component followed by the endpoint.

Component Options

The Pulsar component supports 48 options, which are listed below.

Name Description Default Type

authenticationClass (common)

The Authentication FQCN to be used while creating the client from URI.

String

authenticationParams (common)

The Authentication Parameters to be used while creating the client from URI.

String

configuration (common)

Allows to pre-configure the Pulsar component with common options that the endpoints will reuse.

PulsarConfiguration

serviceUrl (common)

The Pulsar Service URL to point while creating the client from URI.

String

ackGroupTimeMillis (consumer)

Group the consumer acknowledgments for the specified time in milliseconds - defaults to 100.

100

long

ackTimeoutMillis (consumer)

Timeout for unacknowledged messages in milliseconds - defaults to 10000.

10000

long

ackTimeoutRedeliveryBackoff (consumer)

RedeliveryBackoff to use for ack timeout redelivery backoff.

RedeliveryBackoff

allowManualAcknowledgement (consumer)

Whether to allow manual message acknowledgements. If this option is enabled, then messages are not acknowledged automatically after successful route completion. Instead, an instance of PulsarMessageReceipt is stored as a header on the org.apache.camel.Exchange. Messages can then be acknowledged using PulsarMessageReceipt at any time before the ackTimeout occurs.

false

boolean

bridgeErrorHandler (consumer)

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions (if possible) occurred while the Camel consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. Important: This is only possible if the 3rd party component allows Camel to be alerted if an exception was thrown. Some components handle this internally only, and therefore bridgeErrorHandler is not possible. In other situations we may improve the Camel component to hook into the 3rd party component and make this possible for future releases. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored.

false

boolean

consumerName (consumer)

Name of the consumer when subscription is EXCLUSIVE.

sole-consumer

String

consumerNamePrefix (consumer)

Prefix to add to consumer names when a SHARED or FAILOVER subscription is used.

cons

String

consumerQueueSize (consumer)

Size of the consumer queue - defaults to 10.

10

int

deadLetterTopic (consumer)

Name of the topic where the messages which fail maxRedeliverCount times will be sent. Note: if not set, default topic name will be topicName-subscriptionName-DLQ.

String

enableRetry (consumer)

To enable retry letter topic mode. The default retry letter topic uses this format: topicname-subscriptionname-RETRY.

false

boolean

keySharedPolicy (consumer)

Policy to use by consumer when using key-shared subscription type.

Enum values:

  • AUTO_SPLIT

  • STICKY

String

maxRedeliverCount (consumer)

Maximum number of times that a message will be redelivered before being sent to the dead letter queue. If this value is not set, no Dead Letter Policy will be created.

Integer

messageListener (consumer)

Whether to use the messageListener interface, or to receive messages using a separate thread pool.

true

boolean

negativeAckRedeliveryBackoff (consumer)

RedeliveryBackoff to use for negative ack redelivery backoff.

RedeliveryBackoff

negativeAckRedeliveryDelayMicros (consumer)

Set the negative acknowledgement delay.

60000000

long

numberOfConsumers (consumer)

Number of consumers - defaults to 1.

1

int

numberOfConsumerThreads (consumer)

Number of threads to receive and handle messages when using a separate thread pool.

1

int

readCompacted (consumer)

Enable compacted topic reading.

false

boolean

retryLetterTopic (consumer)

Name of the topic to use in retry mode. Note: if not set, default topic name will be topicName-subscriptionName-RETRY.

String

subscriptionInitialPosition (consumer)

Control the initial position in the topic of a newly created subscription. Default is latest message.

Enum values:

  • EARLIEST

  • LATEST

LATEST

SubscriptionInitialPosition

subscriptionName (consumer)

Name of the subscription to use.

subs

String

subscriptionTopicsMode (consumer)

Determines to which topics this consumer should be subscribed to - Persistent, Non-Persistent, or both. Only used with pattern subscriptions.

Enum values:

  • PersistentOnly

  • NonPersistentOnly

  • AllTopics

PersistentOnly

RegexSubscriptionMode

subscriptionType (consumer)

Type of the subscription EXCLUSIVESHAREDFAILOVERKEY_SHARED, defaults to EXCLUSIVE.

Enum values:

  • EXCLUSIVE

  • SHARED

  • FAILOVER

  • KEY_SHARED

EXCLUSIVE

SubscriptionType

topicsPattern (consumer)

Whether the topic is a pattern (regular expression) that allows the consumer to subscribe to all matching topics in the namespace.

false

boolean

pulsarMessageReceiptFactory (consumer (advanced))

Provide a factory to create an alternate implementation of PulsarMessageReceipt.

PulsarMessageReceiptFactory

batcherBuilder (producer)

Control batching method used by the producer.

DEFAULT

BatcherBuilder

batchingEnabled (producer)

Control whether automatic batching of messages is enabled for the producer.

true

boolean

batchingMaxMessages (producer)

The maximum size to batch messages.

1000

int

batchingMaxPublishDelayMicros (producer)

The maximum time period within which the messages sent will be batched if batchingEnabled is true.

1000

long

blockIfQueueFull (producer)

Whether to block the producing thread if pending messages queue is full or to throw a ProducerQueueIsFullError.

false

boolean

chunkingEnabled (producer)

Control whether chunking of messages is enabled for the producer.

false

boolean

compressionType (producer)

Compression type to use.

Enum values:

  • NONE

  • LZ4

  • ZLIB

  • ZSTD

  • SNAPPY

NONE

CompressionType

hashingScheme (producer)

Hashing function to use when choosing the partition to use for a particular message.

Enum values:

  • JavaStringHash

  • Murmur3_32Hash

JavaStringHash

String

initialSequenceId (producer)

The first message published will have a sequence Id of initialSequenceId 1.

-1

long

lazyStartProducer (producer)

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

boolean

maxPendingMessages (producer)

Size of the pending massages queue. When the queue is full, by default, any further sends will fail unless blockIfQueueFull=true.

1000

int

maxPendingMessagesAcrossPartitions (producer)

Deprecated The maximum number of pending messages for partitioned topics. The maxPendingMessages value will be reduced if (number of partitions maxPendingMessages) exceeds this value. Partitioned topics have a pending message queue for each partition.

50000

int

messageRouter (producer)

Custom Message Router to use.

MessageRouter

messageRoutingMode (producer)

Message Routing Mode to use.

Enum values:

  • SinglePartition

  • RoundRobinPartition

  • CustomPartition

RoundRobinPartition

MessageRoutingMode

producerName (producer)

Name of the producer. If unset, lets Pulsar select a unique identifier.

String

sendTimeoutMs (producer)

Send timeout in milliseconds.

30000

int

autoConfiguration (advanced)

The pulsar auto configuration.

AutoConfiguration

autowiredEnabled (advanced)

Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc.

true

boolean

pulsarClient (advanced)

Autowired The pulsar client.

PulsarClient

Endpoint Options

The Pulsar endpoint is configured using URI syntax:

pulsar:persistence://tenant/namespace/topic

with the following path and query parameters:

Path Parameters (4 parameters)

Name Description Default Type

persistence (common)

Required Whether the topic is persistent or non-persistent.

Enum values:

  • persistent

  • non-persistent

String

tenant (common)

Required The tenant.

String

namespace (common)

Required The namespace.

String

topic (common)

Required The topic.

String

Query Parameters (45 parameters)

Name Description Default Type

authenticationClass (common)

The Authentication FQCN to be used while creating the client from URI.

String

authenticationParams (common)

The Authentication Parameters to be used while creating the client from URI.

String

serviceUrl (common)

The Pulsar Service URL to point while creating the client from URI.

String

ackGroupTimeMillis (consumer)

Group the consumer acknowledgments for the specified time in milliseconds - defaults to 100.

100

long

ackTimeoutMillis (consumer)

Timeout for unacknowledged messages in milliseconds - defaults to 10000.

10000

long

ackTimeoutRedeliveryBackoff (consumer)

RedeliveryBackoff to use for ack timeout redelivery backoff.

RedeliveryBackoff

allowManualAcknowledgement (consumer)

Whether to allow manual message acknowledgements. If this option is enabled, then messages are not acknowledged automatically after successful route completion. Instead, an instance of PulsarMessageReceipt is stored as a header on the org.apache.camel.Exchange. Messages can then be acknowledged using PulsarMessageReceipt at any time before the ackTimeout occurs.

false

boolean

consumerName (consumer)

Name of the consumer when subscription is EXCLUSIVE.

sole-consumer

String

consumerNamePrefix (consumer)

Prefix to add to consumer names when a SHARED or FAILOVER subscription is used.

cons

String

consumerQueueSize (consumer)

Size of the consumer queue - defaults to 10.

10

int

deadLetterTopic (consumer)

Name of the topic where the messages which fail maxRedeliverCount times will be sent. Note: if not set, default topic name will be topicName-subscriptionName-DLQ.

String

enableRetry (consumer)

To enable retry letter topic mode. The default retry letter topic uses this format: topicname-subscriptionname-RETRY.

false

boolean

keySharedPolicy (consumer)

Policy to use by consumer when using key-shared subscription type.

Enum values:

  • AUTO_SPLIT

  • STICKY

String

maxRedeliverCount (consumer)

Maximum number of times that a message will be redelivered before being sent to the dead letter queue. If this value is not set, no Dead Letter Policy will be created.

Integer

messageListener (consumer)

Whether to use the messageListener interface, or to receive messages using a separate thread pool.

true

boolean

negativeAckRedeliveryBackoff (consumer)

RedeliveryBackoff to use for negative ack redelivery backoff.

RedeliveryBackoff

negativeAckRedeliveryDelayMicros (consumer)

Set the negative acknowledgement delay.

60000000

long

numberOfConsumers (consumer)

Number of consumers - defaults to 1.

1

int

numberOfConsumerThreads (consumer)

Number of threads to receive and handle messages when using a separate thread pool.

1

int

readCompacted (consumer)

Enable compacted topic reading.

false

boolean

retryLetterTopic (consumer)

Name of the topic to use in retry mode. Note: if not set, default topic name will be topicName-subscriptionName-RETRY.

String

subscriptionInitialPosition (consumer)

Control the initial position in the topic of a newly created subscription. Default is latest message.

Enum values:

  • EARLIEST

  • LATEST

LATEST

SubscriptionInitialPosition

subscriptionName (consumer)

Name of the subscription to use.

subs

String

subscriptionTopicsMode (consumer)

Determines to which topics this consumer should be subscribed to - Persistent, Non-Persistent, or both. Only used with pattern subscriptions.

Enum values:

  • PersistentOnly

  • NonPersistentOnly

  • AllTopics

PersistentOnly

RegexSubscriptionMode

subscriptionType (consumer)

Type of the subscription EXCLUSIVESHAREDFAILOVERKEY_SHARED, defaults to EXCLUSIVE.

Enum values:

  • EXCLUSIVE

  • SHARED

  • FAILOVER

  • KEY_SHARED

EXCLUSIVE

SubscriptionType

topicsPattern (consumer)

Whether the topic is a pattern (regular expression) that allows the consumer to subscribe to all matching topics in the namespace.

false

boolean

bridgeErrorHandler (consumer (advanced))

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions (if possible) occurred while the Camel consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. Important: This is only possible if the 3rd party component allows Camel to be alerted if an exception was thrown. Some components handle this internally only, and therefore bridgeErrorHandler is not possible. In other situations we may improve the Camel component to hook into the 3rd party component and make this possible for future releases. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored.

false

boolean

exceptionHandler (consumer (advanced))

To let the consumer use a custom ExceptionHandler. Notice if the option bridgeErrorHandler is enabled then this option is not in use. By default the consumer will deal with exceptions, that will be logged at WARN or ERROR level and ignored.

ExceptionHandler

exchangePattern (consumer (advanced))

Sets the exchange pattern when the consumer creates an exchange.

Enum values:

  • InOnly

  • InOut

ExchangePattern

batcherBuilder (producer)

Control batching method used by the producer.

DEFAULT

BatcherBuilder

batchingEnabled (producer)

Control whether automatic batching of messages is enabled for the producer.

true

boolean

batchingMaxMessages (producer)

The maximum size to batch messages.

1000

int

batchingMaxPublishDelayMicros (producer)

The maximum time period within which the messages sent will be batched if batchingEnabled is true.

1000

long

blockIfQueueFull (producer)

Whether to block the producing thread if pending messages queue is full or to throw a ProducerQueueIsFullError.

false

boolean

chunkingEnabled (producer)

Control whether chunking of messages is enabled for the producer.

false

boolean

compressionType (producer)

Compression type to use.

Enum values:

  • NONE

  • LZ4

  • ZLIB

  • ZSTD

  • SNAPPY

NONE

CompressionType

hashingScheme (producer)

Hashing function to use when choosing the partition to use for a particular message.

Enum values:

  • JavaStringHash

  • Murmur3_32Hash

JavaStringHash

String

initialSequenceId (producer)

The first message published will have a sequence Id of initialSequenceId 1.

-1

long

maxPendingMessages (producer)

Size of the pending massages queue. When the queue is full, by default, any further sends will fail unless blockIfQueueFull=true.

1000

int

maxPendingMessagesAcrossPartitions (producer)

Deprecated The maximum number of pending messages for partitioned topics. The maxPendingMessages value will be reduced if (number of partitions maxPendingMessages) exceeds this value. Partitioned topics have a pending message queue for each partition.

50000

int

messageRouter (producer)

Custom Message Router to use.

MessageRouter

messageRoutingMode (producer)

Message Routing Mode to use.

Enum values:

  • SinglePartition

  • RoundRobinPartition

  • CustomPartition

RoundRobinPartition

MessageRoutingMode

producerName (producer)

Name of the producer. If unset, lets Pulsar select a unique identifier.

String

sendTimeoutMs (producer)

Send timeout in milliseconds.

30000

int

lazyStartProducer (producer (advanced))

Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing.

false

boolean

Message Headers

The Pulsar component supports 15 message header(s), which is/are listed below:

Name Description Default Type

properties (consumer)

Constant: PROPERTIES

The properties attached to the message.

Map

producer_name (consumer)

Constant: PRODUCER_NAME

The producer name who produced the message.

String

sequence_id (consumer)

Constant: SEQUENCE_ID

The sequence id associated with the message.

long

publish_time (consumer)

Constant: PUBLISH_TIME

The publish time of the message.

long

message_id (consumer)

Constant: MESSAGE_ID

The unique message ID associated with the message.

MessageId

event_time (consumer)

Constant: EVENT_TIME

The event time associated with the message.

long

key (consumer)

Constant: KEY

The key of the message.

String

key_bytes (consumer)

Constant: KEY_BYTES

The bytes in key.

byte[]

topic_name (consumer)

Constant: TOPIC_NAME

The topic the message was published to.

String

message_receipt (consumer)

Constant: MESSAGE_RECEIPT

The message receipt.

PulsarMessageReceipt

CamelPulsarProducerMessageKey (producer)

Constant: KEY_OUT

The key of the message for routing policy.

String

CamelPulsarProducerMessageProperties (producer)

Constant: PROPERTIES_OUT

The properties of the message to add.

Map

CamelPulsarProducerMessageEventTime (producer)

Constant: EVENT_TIME_OUT

The event time of the message message.

Long

CamelPulsarProducerMessageDeliverAt (producer)

Constant: DELIVER_AT_OUT

Deliver the message only at or after the specified absolute timestamp. The timestamp is milliseconds and based on UTC (eg: System.currentTimeMillis) Note: messages are only delivered with delay when a consumer is consuming through a Shared subscription. With other subscription types, the messages will still be delivered immediately.

Long

CamelPulsarRedeliveryCount (consumer)

Constant: PULSAR_REDELIVERY_COUNT

The message redelivery count, redelivery count maintain in pulsar broker.

int