Major It seems from Atlas db that a lot of requests are not cleared by GC:
select sb.statusCode, count(*) from request_queue rq, status_BoL sb, request_BoL rb where rq.ID = rb.request_queueID and sb.request_BoLID=rb.ID and rq.config_RequestTypeID="BOL" group by sb.statusCode;
+------------+----------+
| statusCode | count(*) |
+------------+----------+
| 0 | 184 |
| 1 | 91 |
| 5 | 122 |
| 17 | 2464 |
| 18 | 1438837 |
| 20 | 1535 |
| 21 | 352375 |
+------------+----------+