}

                    // Normal polling interval: max 5 seconds, increased based on failures
                    long pollInterval = Math.min(MAX_POLL_INTERVAL, BASE_POLL_INTERVAL + (registration.getHeartbeatFailures() * 500));
                    Thread.sleep(pollInterval);

                } catch (InterruptedException e) {
                    log.debug("Async notification monitoring interrupted for {}", registrationId);

        this.heartbeatFailures++;
    }

    /**
     * Gets the number of consecutive heartbeat failures.
     *
     * @return the number of consecutive heartbeat failures
     */
    public int getHeartbeatFailures() {
        return heartbeatFailures;
    }

    /**
     * Checks if this registration has expired based on the timeout.
     *
     * @param timeoutMs the timeout in milliseconds