Pulsar Node.js client configurations

Client configs

The following configurable parameters are available for Pulsar Node.js clients:

Parameter	Description	Default
serviceUrl	The connection URL for the Pulsar cluster. See above for more info.
authentication	Configure the authentication provider. (default: no authentication). See mTLS authentication for more info.
operationTimeoutSeconds	The timeout for Node.js client operations (creating producers, subscribing to and unsubscribing from topics). Retries occur until this threshold is reached, at which point the operation fails.	30
ioThreads	The number of threads to use for handling connections to Pulsar brokers.	1
messageListenerThreads	The number of threads used by message listeners (consumers and readers).	1
concurrentLookupRequest	The number of concurrent lookup requests that can be sent on each broker connection. Setting a maximum helps to keep from overloading brokers. You should set values over the default of 50000 only if the client needs to produce and/or subscribe to thousands of Pulsar topics.	50000
tlsTrustCertsFilePath	The file path for the trusted TLS certificate.
tlsValidateHostname	The boolean value of setup whether to enable TLS hostname verification.	false
tlsAllowInsecureConnection	The boolean value of setup whether the Pulsar client accepts untrusted TLS certificate from broker.	false
statsIntervalInSeconds	Interval between each stat info. Stats is activated with positive statsInterval. The value should be set to 1 second at least	600
log	A function that is used for logging.	console.log

Producer configs

Parameter	Description	Default
topic	The Pulsar topic to which the producer publishes messages. The topic format is <topic-name> or <tenant-name>/<namespace-name>/<topic-name>. For example, sample/ns1/my-topic.
producerName	A name for the producer. If you do not explicitly assign a name, Pulsar automatically generates a globally unique name. If you choose to explicitly assign a name, it needs to be unique across all Pulsar clusters, otherwise the creation operation throws an error.
sendTimeoutMs	When publishing a message to a topic, the producer waits for an acknowledgment from the responsible Pulsar broker. If a message is not acknowledged within the threshold set by this parameter, an error is thrown. If you set sendTimeoutMs to -1, the timeout is set to infinity (and thus removed). Removing the send timeout is recommended when using Pulsar's message de-duplication feature.	30000
initialSequenceId	The initial sequence ID of the message. When producer send message, add sequence ID to message. The ID is increased each time to send.
maxPendingMessages	The maximum size of the queue holding pending messages (i.e. messages waiting to receive an acknowledgment from the broker). By default, when the queue is full all calls to the send method fails unless blockIfQueueFull is set to true.	1000
maxPendingMessagesAcrossPartitions	The maximum size of the sum of partition's pending queue.	50000
blockIfQueueFull	If set to true, the producer's send method waits when the outgoing message queue is full rather than failing and throwing an error (the size of that queue is dictated by the maxPendingMessages parameter); if set to false (the default), send operations fails and throw a error when the queue is full.	false
messageRoutingMode	The message routing logic (for producers on partitioned topics). This logic is applied only when no key is set on messages. The available options are: round robin (RoundRobinDistribution), or publishing all messages to a single partition (UseSinglePartition, the default).	UseSinglePartition
hashingScheme	The hashing function that determines the partition on which a particular message is published (partitioned topics only). The available options are: JavaStringHash (the equivalent of String.hashCode() in Java), Murmur3_32Hash (applies the Murmur3 hashing function), or BoostHash (applies the hashing function from C++'s Boost library).	BoostHash
compressionType	The message data compression type used by the producer. The available options are LZ4, and Zlib, ZSTD, SNAPPY.	Compression None
batchingEnabled	If set to true, the producer send message as batch.	true
batchingMaxPublishDelayMs	The maximum time of delay sending message in batching.	10
batchingMaxMessages	The maximum size of sending message in each time of batching.	1000
properties	The metadata of producer.

Consumer configs

Parameter	Description	Default
topic	The Pulsar topic on which the consumer establishes a subscription and listen for messages.
topics	The array of topics.
topicsPattern	The regular expression for topics.
subscription	The subscription name for this consumer.
subscriptionType	Available options are Exclusive, Shared, Key_Shared, and Failover.	Exclusive
subscriptionInitialPosition	Initial position at which to set cursor when subscribing to a topic at first time.	SubscriptionInitialPosition.Latest
ackTimeoutMs	Acknowledge timeout in milliseconds.	0
nAckRedeliverTimeoutMs	Delay to wait before redelivering messages that failed to be processed.	60000
receiverQueueSize	Sets the size of the consumer's receiver queue, i.e. the number of messages that can be accumulated by the consumer before the application calls receive. A value higher than the default of 1000 could increase consumer throughput, though at the expense of more memory utilization.	1000
receiverQueueSizeAcrossPartitions	Set the max total receiver queue size across partitions. This setting is used to reduce the receiver queue size for individual partitions if the total exceeds this value.	50000
consumerName	The name of consumer. Currently(v2.4.1), failover mode use consumer name in ordering.
properties	The metadata of consumer.
listener	A listener that is called for a message received.
readCompacted	If enabling readCompacted, a consumer reads messages from a compacted topic rather than reading a full message backlog of a topic. A consumer only sees the latest value for each key in the compacted topic, up until reaching the point in the topic message when compacting backlog. Beyond that point, send messages as normal. readCompacted can only be enabled on subscriptions to persistent topics, which have a single active consumer (like failure or exclusive subscriptions). Attempting to enable it on subscriptions to non-persistent topics or on shared subscriptions leads to a subscription call throwing a PulsarClientException.	false

Reader configs

Parameter	Description	Default
topic	The Pulsar topic on which the reader establishes a subscription and listen for messages.
startMessageId	The initial reader position, i.e. the message at which the reader begins processing messages. The options are Pulsar.MessageId.earliest (the earliest available message on the topic), Pulsar.MessageId.latest (the latest available message on the topic), or a message ID object for a position that is not earliest or latest.
receiverQueueSize	Sets the size of the reader's receiver queue, i.e. the number of messages that can be accumulated by the reader before the application calls readNext. A value higher than the default of 1000 could increase reader throughput, though at the expense of more memory utilization.	1000
readerName	The name of the reader.
subscriptionRolePrefix	The subscription role prefix.
readCompacted	If enabling readCompacted, a consumer reads messages from a compacted topic rather than reading a full message backlog of a topic. A consumer only sees the latest value for each key in the compacted topic, up until reaching the point in the topic message when compacting backlog. Beyond that point, send messages as normal. readCompacted can only be enabled on subscriptions to persistent topics, which have a single active consumer (like failure or exclusive subscriptions). Attempting to enable it on subscriptions to non-persistent topics or on shared subscriptions leads to a subscription call throwing a PulsarClientException.	false