NATS Consumer not reading all the messages of a subject from a stream

[kruthik-nivas]

I am trying to build a NATS consumer that reads the last message from all subjects and then closes the connection. I need to do this periodically. However, my current implementation reads only up to 500 messages. Even though there are more than 1500 messages. I have also tried reading all messages from a single subject which also had more than 1200 messages and i still was able to get only 500.

How can I consume and also ensure it reads the last message from all subjects without this limitation?

The code i used from NATS BY EXAMPLE :

    val options = Options.builder()
        .server("nats://url:port")
        .authHandler(Nats.credentials("/Users/check/key.txt"))
        .build()
    val connection = Nats.connect(options)
    val js = connection.jetStream()
    val consumerConfig = ConsumerConfiguration
        .builder()
        .filterSubject("subject.>")
        .deliverPolicy(DeliverPolicy.LastPerSubject)
        .build()

    // start the consumer
    val streamContext: StreamContext = js.getStreamContext("STREAM_NAME")
    val consumerContext = streamContext.createOrUpdateConsumer(consumerConfig)

    val fetchConsumeOptions = FetchConsumeOptions.builder().noWait().build()
    try {
        consumerContext.fetch(fetchConsumeOptions).use { fetchConsumer ->
            var count = 0
            while (true) {
                val msg = fetchConsumer.nextMessage() ?: break
                count++
                println("\nMessage Received:")
                println(msg.subject)
                println(String(msg.data, StandardCharsets.UTF_8))
                msg.ack()
            }
            fetchConsumer.stop()
            println(count)
        }
    } catch (e: Exception) {
        e.printStackTrace()
    }