PubSub not re-delivering message after ack deadline - publish-subscribe

Question

I have two subscriber pointing to same subscription of topic use case.
As per document pub sub redeliver the message if subscriber took more time than Acknowledgement deadline to acknowledge the message.
I have configure the default value which is 10 sec. But processing takes approx ~ 1 min to complete and acknowledge.
Below is my sample code
public class SubscribeAsyncExample {
private Subscriber subscriber = null;
#PostConstruct
public void init() throws Exception {
// TODO(developer): Replace these variables before running the sample.
String projectId = "your-project-id";
String subscriptionId = "your-subscription-id";
subscribeAsyncExample(projectId, subscriptionId);
}
public void subscribeAsyncExample(String projectId, String subscriptionId) {
ProjectSubscriptionName subscriptionName = ProjectSubscriptionName.of(projectId, subscriptionId);
// Instantiate an asynchronous message receiver.
MessageReceiver receiver = (PubsubMessage message, AckReplyConsumer consumer) -> {
// Handle incoming message, then ack the received message.
System.out.println("Id: " + message.getMessageId());
System.out.println("Data: " + message.getData().toStringUtf8());
int sleepingTime = 20000;
System.out.println("sleepingTime:" + sleepingTime);
try {
Thread.sleep(sleepingTime);
} catch (InterruptedException e) {
e.printStackTrace();
}
consumer.ack();
System.out.println("test completed");
};
try {
subscriber = Subscriber.newBuilder(subscriptionName, receiver).build();
// Start the subscriber.
subscriber.startAsync().awaitRunning();
System.out.printf("Listening for messages on %s:\n", subscriptionName.toString());
// Allow the subscriber to run for 30s unless an unrecoverable error occurs.
// subscriber.awaitTerminated(30, TimeUnit.SECONDS);
} catch (Exception e) {
e.printStackTrace();
}
}
#PreDestroy
public void preDestroy() throws Exception {
// Shut down the subscriber after 30s. Stop receiving messages.
subscriber.stopAsync();
}
}```
Below is Response
20:53:24,300 INFO [stdout] (Thread-128) Id: 1288313732423842
20:53:24,300 INFO [stdout] (Thread-128) Data: abc13
**20:53:24,300 INFO** [stdout] (Thread-128) sleepingTime:20000
**20:53:44,300 INFO** [stdout] (Thread-128) test completed

Answer 1

When using the Cloud Pub/Sub client libraries, the deadline is automatically extended up to the MaxAckExtensionPeriod specified in the Subscriber.Buider. This extension period defaults to one hour. To change this value, you'd want to change the line that creates the subscriber as follows:
subscriber = Subscriber.newBuilder(subscriptionName, receiver)
.setMaxAckExtensionPeriod(Duration.ofSeconds(10))
.build();