protected long getNextScan(Subscription sub) {
SubscriptionHistory history = sub.getHistory();
Long fail_count = (Long) sub.getUserData(SCHEDULER_FAILED_SCAN_CONSEC_KEY);
if (fail_count != null) {
long fail_time = ((Long) sub.getUserData(SCHEDULER_FAILED_SCAN_TIME_KEY)).longValue();
long fails = fail_count.longValue();
long backoff = FAIL_INIT_DELAY;
for (int i = 1; i < fails; i++) {
backoff <<= 1;
if (backoff > FAIL_MAX_DELAY) {
backoff = FAIL_MAX_DELAY;
break;
}
}
return (fail_time + backoff);
}
return (history.getNextScanTime());
}
