Package eu.vstoyanov.natsy.jetstream

Class ConsumerContext

  • All Implemented Interfaces:
    
public final class ConsumerContext

    Context for JetStream consumer operations

    Provides access to consumer management and monitoring including:

    • Consumer information and updates

    • Pause/resume operations

    • Monitoring metrics

    Example usage:

    val consumerCtx = js.consumer("MY_STREAM", "MY_CONSUMER") {
    durable = "MY_CONSUMER"
    ackPolicy = AckPolicy.EXPLICIT
    maxDeliver = 5
}.getOrThrow()

// Update the consumer
consumerCtx.update {
    maxDeliver = 10
}

// Pause the consumer until it is explicitly resumed
consumerCtx.pause()

// ...or until a deadline, after which the server resumes it automatically
consumerCtx.pause(30.minutes)

// Check status
val isPaused = consumerCtx.isPaused()

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description

    • Constructor Summary

      Constructors 
      Constructor Description

    • Enum Constant Summary

      Enum Constants 
      Enum Constant Description

    • Method Summary

      Modifier and Type Method Description
      final String getStreamName() Name of the stream this consumer belongs to
      final String getConsumerName() Name of the consumer
      final Result<ConsumerInfo> getInfo() Get current consumer information
      final Result<ConsumerInfo> update(Function1<ConsumerConfigBuilder, Unit> block) Update the consumer configurationApplies the configuration block to update consumer settings.
      final Result<Boolean> delete() Delete the consumerPermanently deletes the consumer.
      final Result<PauseResponse> pause(Instant until) Pause the consumerTemporarily pauses message delivery to the consumer.
      final Result<PauseResponse> pause(Duration duration) Pause the consumer for a durationConvenience over pause with an absolute deadline.
      final Result<Boolean> resume() Resume the consumerResumes message delivery to a paused consumer.
      final Boolean isPaused() Check if the consumer is currently paused
      final Long deliveredCount() Get the count of delivered messages
      final Long ackPendingCount() Get the count of pending acknowledgments
      final Long waitingPullCount() Get the count of waiting pull requests (for pull consumers)
      final Long pendingMessageCount() Get the count of pending messages (messages waiting to be delivered)
      final Boolean isEphemeral() Check if this consumer is ephemeral (not durable)Ephemeral consumers are automatically cleaned up when they become inactive, while durable consumers persist until explicitly deleted.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

    • Method Detail

      • getInfo

         final Result<ConsumerInfo> getInfo()

        Get current consumer information

        Returns:

        Result containing ConsumerInfo on success or exception on failure

      • update

         final Result<ConsumerInfo> update(Function1<ConsumerConfigBuilder, Unit> block)

        Update the consumer configuration

        Applies the configuration block to update consumer settings. Only the properties assigned in the block are changed; everything else keeps the value the server currently holds, including settings natsy's DSL does not model.

        Note: Not all properties can be updated after creation. Attempting to change immutable properties will result in an error from the NATS server.

        Parameters:
        block - Configuration block with consumer updates
        Returns:

        Result containing updated ConsumerInfo on success

      • delete

         final Result<Boolean> delete()

        Delete the consumer

        Permanently deletes the consumer. This operation cannot be undone. After deletion, the consumer context should not be used.

        Returns:

        Result containing true on successful deletion

      • pause

         final Result<PauseResponse> pause(Instant until)

        Pause the consumer

        Temporarily pauses message delivery to the consumer. Messages will continue to accumulate but won't be delivered until the deadline passes or resume is called.

        NATS models pausing purely as a deadline: a pause_until that is absent or already in the past is a resume request on the same endpoint. Passing a non-future until is therefore rejected instead of silently resuming, and "pause until further notice" (the default) is expressed as a far-future deadline that resume clears immediately.

        Parameters:
        until - when the consumer should automatically resume; must be in the future.
        Returns:

        Result containing PauseResponse on success — success means the consumer is paused. Fails if until is not in the future, or if the server did not pause the consumer.

      • pause

         final Result<PauseResponse> pause(Duration duration)

        Pause the consumer for a duration

        Convenience over pause with an absolute deadline. Duration.INFINITE pauses until resume is called.

        Parameters:
        duration - how long to pause for; must be positive
        Returns:

        Result containing PauseResponse on success

      • resume

         final Result<Boolean> resume()

        Resume the consumer

        Resumes message delivery to a paused consumer.

        Returns:

        Result containing true on successful resume

      • isPaused

         final Boolean isPaused()

        Check if the consumer is currently paused

        Returns:

        true if the consumer is paused, false otherwise

      • deliveredCount

         final Long deliveredCount()

        Get the count of delivered messages

        Returns:

        Number of messages delivered by this consumer

      • ackPendingCount

         final Long ackPendingCount()

        Get the count of pending acknowledgments

        Returns:

        Number of unacknowledged messages

      • waitingPullCount

         final Long waitingPullCount()

        Get the count of waiting pull requests (for pull consumers)

        Returns:

        Number of waiting pull requests

      • pendingMessageCount

         final Long pendingMessageCount()

        Get the count of pending messages (messages waiting to be delivered)

        Returns:

        Number of pending messages

      • isEphemeral

         final Boolean isEphemeral()

        Check if this consumer is ephemeral (not durable)

        Ephemeral consumers are automatically cleaned up when they become inactive, while durable consumers persist until explicitly deleted.

        Returns:

        true if the consumer is ephemeral, false if durable