long ts1 = System.currentTimeMillis();
String memId;
if (visibilityTO > 0) {
memId = jedis.lpop(queue.getRelativeUrl() + "-" + shard + "-Q");
} else {
memId = jedis.lindex(queue.getRelativeUrl() + "-" + shard + "-Q", i);
}
long ts2 = System.currentTimeMillis();