Unbounded KafkaTemplate.send().get() in KpiProducer — potential blocking under broker latency

Summary

While reviewing Kafka producer usage patterns in this module, I noticed that KpiProducer calls KafkaTemplate.send().get() without a timeout. This can cause the calling thread to block indefinitely if the broker is slow, unreachable, or the topic is unavailable. I haven't seen this cause a concrete failure in this repo — I'm flagging it as a possible hardening opportunity, not reporting an incident.

Location

spring-kafka-4/src/main/java/com/baeldung/kafka/batch/KpiProducer.java:17

public void sendMessage(String topic, String message) throws ExecutionException, InterruptedException {
    kafkaTemplate.send(topic, message).get();   // line 17 — no timeout
    this.kafkaTemplate.flush();
}

Why this can matter

Future.get() with no arguments blocks the calling thread until the send completes, with no upper bound. If the broker is unreachable, the partition leader is unavailable, or there's elevated network latency, this call can hang far longer than a caller would expect. If sendMessage is ever invoked from a request-handling thread or a bounded thread pool, that shape can lead to thread starvation under load.

The usual mitigation is Future.get(timeout, TimeUnit), so a slow or unavailable broker surfaces as a handled TimeoutException instead of an unbounded block.

What I checked before opening this

• I searched the repo and found KpiProducer is only referenced by KafkaBatchProcessingLiveTest and KafkaNoBatchLiveTest, both of which exercise it against an EmbeddedKafkaBroker in tests.
• I did not find a production/application caller of KpiProducer.sendMessage() anywhere in this repo. So I can't say this pattern has caused (or would currently cause) an actual problem here — this is a potential-risk report, not a report of observed behavior.
• If this class is intentionally a minimal/naive example (e.g., for later contrast with a batching or async approach elsewhere in this module), this issue may simply not apply — feel free to close it in that case.

Suggested change (optional)

kafkaTemplate.send(topic, message).get(5, TimeUnit.SECONDS);

(with whatever timeout/exception-handling strategy fits this tutorial's purpose).

Additional context

For what it's worth, I've applied this same fix shape (bounded .get(timeout, TimeUnit) instead of unbounded .get()) in a reproducible production-pattern lab I maintain: https://github.com/Joaquinriosheredia/Java-Production-Labs — see commit 01cee184. I'm sharing it only as an illustration of what the change looks like, not as evidence that this repository has the same issue — entirely your call whether it's worth adopting here.

Thanks for maintaining this repo — happy to close this out or help however's useful if it turns out not to be relevant.